GermGuardian AC4825 Air Purifier Review – Hands-On Test & Details

GermGuardian AC4825 review featured image

After having to deal with dust and other air quality issues, I picked up a GermGuardian AC4825 of my own. It wasn’t hard to find – after all, it’s one of the most popular purifiers sold today.

In my GermGuardian AC4825 review I’ll help you decide if it’s a good buy or not. I own it and I’ve put it through its paces personally.

I’d love to help you make the best buying decision for your money and experience better air at home just like I have. Believe me when I say a good air purifier is a great buy – but you’ve got to shop wisely.


My AC4825 video review

GermGuardian AC4825 Air Purifier Review - Honest Review

Unpacking & first impressions


GermGuardian AC4825 packaging and unboxing image

My AC4825 arrived quickly and after removing it from the shipping box, inside was a purifier I’d come to love soon enough. It’s well-packaged and the owner’s manual is placed right on top to be sure you find it easily. Eco-friendly recycled corrugated cardboard is used for the packaging and it’s easy to unbox. We’re off to a great start!

I’m no stranger to air purifiers and home air quality products, so I didn’t think I would get excited about another air purifier. It turned out I was wrong.

For some reason, it was still fun to pick up my AC4825 from the UPS Store for the first time and unbox it. What is it really like, I wondered? How well does it work?

It arrived well-packaged and features recycled cardboard inserts that hold it in place. The owner’s manual is right on top so you can’t miss it when opening it up the first time.

Build quality and fit & finish

GermGuardian AC4825 closeup quality image
After opening and unpacking it (which consisted of removing the corrugated cardboard inserts – styrofoam isn’t used with this one) I finally to check it out and turn it on!

The AC4825 is built with a solid, good-feeling ABS plastic body and has a nice low-gloss black finish. The top features a matte silver finish with a satin black top section surrounding the controls.

I didn’t get any kind of impressions of it having any poor-quality construction or any similar flaws. It looks good, and honestly, I’m happy with it.

Personally, I’ve never been a big fan of shiny finishes on products like this, so it’s a relief that it doesn’t stand out in a flashy way in the rooms I’ve used it in.

I have to say it’s well put together and well-made. Parts line up well, are tightly assembled, and there aren’t noticeable gaps or quality control issues to speak of.

Overall, it looks like it cost more than I spent.

If there’s one thing I’ve learned over the years, it’s that gaps and misaligned parts are a sign of build issues. There’s none of that here.

Checking out the controls

GermGuardian AC4825 top down view of controls
Operating the AC4825 is extremely easy. In the picture above, you can see 1) the 3-speed fan control, and 2) the ultraviolet-light (UV-C) germ killing feature button switch.

The fan control feels great, and the switching is somewhere between a “soft” feel and a firm feel. It’s not too light, and yet not too hard to turn. I’m pretty happy with it, because it doesn’t feel like you’re going to miss position #2 and skip over to #3, for example.

The fan switch is actually quiet in operation and smooth to use.

The ultraviolet light (UV-C) germ killing feature

The AC4825, like several other GermGuardian air purifier models, features a bulb and titanium-oxide germ killing feature which radiates germs passing through it and renders them inactive by affecting their molecular and protein structures.

However, you’ll have to manually turn on this option.

To do so, the purifier must be at least in position #1 (low speed) before the control will work. You can tell it’s on by the glowing blue trim around the body as pictured here.

GermGuardian AC4825 side view UV-C feature glowing

When activated, you’ll see the small, thin light strip on the base of the silver decorative top glow blue from inside. Don’t worry though – you’re not in any danger from exposure to ultraviolet light. It’s safely contained inside.

I like how this feature is used as a decorative accent when active. That’s a nice touch!

One complaint I have, however, is that once it’s in use, switching the purifier off then on again won’t re-activate the feature.

You’ll have to do so manually, as there’s no memory feature (unlike some competitors) to restore the setting the next time you switch it on.

While not a “deal-breaker”, that’s a small detail to be aware of.

Specifications & CADR ratings

GermGuardian AC4825 Specifications
  • Room size rating: 167 sq. ft (medium room)
  • UV-C germ killing light
  • Titanium Oxide odor molecule remover
  • 3-speed fan control
  • True HEPA filter w/ activated carbon filter
  • CADR (Clean Air Delivery Rate) ratings: Dust (118), pollen (125), smoke (108)
  • AHAM Verified & Energy Star Certified
  • Low-noise fan setting
  • Replaceable UV bulb
  • Dual-section blower fans
  • Simple rotary control
  • Pushbutton on/off UV switch
  • Filter replacement reminder
  • UV bulb replacement indicator
  • 3-year limited warranty
  • Replacement filter: FILTER B (FLT4825)
  • Power use: 55W (max. fan speed)
  • Carrying handle
  • Weight: 8.65 lbs
  • Cord length: 6 ft.
  • Control location: top
  • Size: 6.75 x 10.25 x 21.5″

If you’re not already familiar with it, it’s helpful to understand more about the Clean Air Delivery Rate (CADR) standard used by the industry. This is a voluntary lab-tested rating of an air purifier’s cleaning ability.

GermGuardian AC4825 air purifier CADR ratings AHAM label

The AC4825’s CADR ratings are shown here.

The AHAM is an organization that verifies the testing results of home appliances & performs lab testing for appliance manufacturers although it’s not required by law.

In simple terms, it’s a rating used to help you know before buying an air purifier’s effectiveness. The rating numbers mean “higher is better” as they’re lab tested using a series of tests to measure their air cleaning effectiveness.

In the case of this model, the specs are good and you’re assured you’re getting proven performance.

Size and thoughts on using a “tower” purifier

AC4825 purifier measuring height

At nearly 22″ in height, it’s not a small device. “Tower” air purifiers are simply those that are taller and don’t have a low-profile design and stand tall on the floor.

They’re taller due to having more fans to provide more airflow.

It’s important to make sure you have enough room before buying. A great place is near a door and not backed into a corner in the room.

Be sure to give it lots of room (about 2 feet in front and back) as it needs space to circulate air efficiently.

Carrying the purifier

GermGuardian AC4825 being carried by handle

One thing I like is being able to carry it easily from place to place at home using the built-in carrying handle area. At the rear of the top, there’s a recessed area where your fingers have plenty of room to pick it up securely.

It’s a nice touch I didn’t notice at first bout after moving it around to find the ideal place in my home, I found it handy.

AC4825 power use measurements

Image of GermGuardian AC4825 power use being measured

Pictured: I measured power use (in Watts) for all 4 recordings (3 speeds plus off).  I recorded power meter readings both with and without the UV-C feature switched on. Overall, it uses a relatively small amount and it’s not an energy hog at all.

How many watts does the AC4825 use?

Unfortunately, the owner’s manual doesn’t go into detail about energy for the various modes you can use.

Rather than guess, I measured power use in Watts for all speed settings with and without the UV-C feature switched on. Note that the UV-C option uses about 4W of power (larger models use 8W).

ModePower Use, UV-C OffPower Use, UV-C On

Overall, it doesn’t use much power at any setting although it’s a bit more efficient on high or medium. For those speeds, the fan is running faster and you’ll get faster air cleaning. The drawback is a bit more noise.

As the UV-C feature uses only about 4W, there’s no need to worry if leaving it on all the time will affect your energy bill.

Air cleaning ability & performance

GermGuardian FLT4825 dirty filter vacuum example image

My purifier’s filter (the FLT4825 filter that’s installed at the factory) trapped a HUGE amount of dust! You can prolong the pre-filter life by vacuuming off excessive dust or hair as needed, which I did. Dust is a really big air quality problem in my home and the AC4825 made a big difference when in use.

I’ve let it run all day while at work so I could come home to fresh, clean air, and it works well. Where I live I have to suffer every day from heavy dust which I absolutely hate!

The purifier’s filter picked up a HUGE amount of dust and did well to relieve my problems, in addition to capturing light odors well, too.

As far as odor absorption performance goes, it’s not on par with more expensive models like the Winix 5500-2, but it’s pretty good for everyday needs in my opinion.

The thing to remember is that air purifiers work by cycling air in a room and it takes time to cycle & filter the entire room’s air.

GermGuardian AC4825 square feet coverage and room size

This model is recommended for room sizes that are medium in size. That being said, there’s absolutely no reason it can’t be used in a small room!

You’ll find that it cleans the air even faster in that case.

It’s sized for rooms about 167 square feet in size which is roughly a 10 x 16.5 ft room. Bear in mind that this is an approximate size used – it doesn’t have to be used in a room exactly that size.

When used in larger rooms the amount of time required to fully cycle and clean the air increases depending on the amount of space inside the room.

Filter ability

GermGuardian AC4900CA filter close up

The AC4825’s HEPA filter (seen here) section is made up of a folded, dense fiber material. A second section, the pre-filter/activated carbon filter is responsible for trapping larger particles as well as odors and volatile organic compounds (VOCs) in the air. It’s capable of excellent filtering ability and works well. The filter can capture nearly 100% of all particulates in its airflow down to 0.3 microns in size!

The high-efficiency particulate air (HEPA) filter is fantastic for removing the most common air quality issues (especially those that cause allergies!).

Here’s the basic list of air contaminants the AC4825 can remove:

  • Pet dander
  • Pet hair (thanks to the pre-filter)
  • Dust mite allergens
  • Pollen
  • Dust
  • Home construction particles
  • Smoke residue
  • Smoke odors
  • Chemical and organic odors
  • Chemical vapors

Essentially, this is a 2-stage filter assembly made up of 2 parts: the pre-filter/activated carbon filter and an extra 2nd section, the HEPA filter, for a total of 3 filters.

The pre-filter section is a less dense & thin section covering the active carbon filter. Its job it to capture larger items in the air like pet hair, dust, and so on before they reach the HEPA filter.

The active carbon filter traps odors and other chemical substances in the air.

Finally, the HEPA filter captures an amazing 99.97% of particles passing through it down to 0.3 microns in size. That’s less than 1/1,000,000 of a meter!

That means it’s capable of capturing elements that are much smaller than you can see with your eye (microscopic).

It’s a great filter and works well. I noticed fresher air soon after using it for the first time, and I’m pleased with it.

The UV-C germ killing feature

GermGuardian UV-C and Ti02 germ killing badgesBy touching the UV button on top, you switch on the germ killing feature. It’s a great addition not found in many competing products.

It’s also perfectly silent and doesn’t cause any noise or produce any side effects.

When on, the blue trim on the base of the silver top section glows blue to show the bulb is working. The technology works using the science of ultraviolet light (UV) to affect microbes in the air, coupled with titanium dioxide to remove airborne contaminants.

As stated in the owner’s manual:

UV-C light technology works with filters to enhance the elimination of airborne germs. Titanium Dioxide is activated by the UV-C light to decompose the remaining odor molecules
caused by smoking, cooking, and pets.Author

Essentially, air passing through has the UV light irradiating into it and microbes in the air are destroyed. It can help prevent sickness and other respiratory problems caused by germs.

Does the AC4825 produce ozone?

Some people wonder if air purifiers can cause headaches. As I explain more in this post, an air purifier that uses a filter to clean the air doesn’t produce emissions to cause unwanted effects.

The UV-C option is completely enclosed and you’re in no danger of skin UV exposure. The AC4825 is perfectly safe and healthy as it does not produce unsafe ozone levels.

In fact, it produces 1/20th of the level considered acceptable by the Health Canada Guideline 2010 based on exposure levels & time considered acceptable.

You’re perfectly safe and won’t have to worry about ozone while using it.

Filter & UV bulb replacement indicators & cost

Replacement indicator lights

The purifier features a helpful way of indicating when it’s time to check and possibly replace the filters. After about 6 months of use, the green LED near the fan switch will blink red to indicate this (see the chart below).

If your filter has had very light use and isn’t heavily used, you can reset the indicator by holding the UV-C button for 5 seconds.

In the case of replacement for the UV-C feature’s bulb, the blue light will blink.

Blinking Light TypeMeaning
Blinking blue light(UV-C glow trim blinking) UV bulb needs replacement
Red blinking lightThe filter needs check/replacement

Filter life and costs

GermGuardian FLT4825 replacement filter
The FLT4825 is
the genuine replacement filter from GermGuardian. It includes both the HEPA filter and an active carbon filter section, too. While the genuine replacement filter is only around $30+, you can save money by buying 3rd party replacement filters.

Expect to replace a filter after about 6-8 months; however, this depends greatly on use. For example, if you’re a smoker or have indoor pets you can expect to replace the filter when reminded.

For situations where the air quality demands are lower you’ll get even more life out of it.

Replacement filters cost around $30 (or a bit over that) for the genuine GermGuardian brand. However, 3rd party budget models are available which contain 1 less expensive filter or 2 filters in the box. If you’re concerned about maintenance costs that’s a great option.

How hard is it to replace the filter?

GermGuardian AC4825 filter removal image
Filter replacement is easy and only takes a few seconds. I was pleasantly surprised by how easy it is.

It’s just a few simple steps:

  1. Press down on the release tab on the rear cover
  2. Pull the cover down and out (there are 2 tabs on the bottom which rest in tab slots)
  3. Using your fingers, pull the filter out and down to remove it
  4. Replace filter using the opposite motion
  5. Insert the cover’s tabs in the base
  6. Swing the cover up and snap the release tab back in place

…and you’re done! I’ve demonstrated this in my video review as well, so be sure to watch that if you’re interested.

UV-C bulb replacement & pricing

GermGuardian AC4825 UV bulb cover diagram

UV bulb replacement is pretty straightforward. The owner’s manual clarifies what you’ll need to do for bulb replacement (which is typically after 10-12 months). You’ll need a Phillips screwdriver (not included) to remove 2 screws, unplug the old bulb, and insert then a new one. Overall, it’s pretty simple to do, so don’t worry about it. Additionally, if you rarely use the feature you’ll never have to do it, anyway.

LB4000 UV replacement bulb
The GermGuardian replacement UV bulb #LB4000. Expect to pay around $25 or so for one when replacing it. The company’s life rating is 10-12 months, although a few owners have reported shorter life (which unfortunately is a problem with many bulbs in general).

Replacement bulbs cost about $25. To replace the bulb, you’ll need a Phillips head screwdriver to remove the rear metal bulb cover. It’s accessible once you’ve removed the filter after opening the cover.

Once the metal cover is removed you simply slide out the old bulb and replace it with a new one. Overall, it’s easy to do.

The bulb is rated at 10-12 months of life expectancy, although a few owners have reported that their bulbs died after only a few months.

The owner’s manual

germguardian ac4825 owners manual image
I was pleasantly surprised to find that the purifier included a solid, well-made owner’s manual with clear instructions and helpful information. Basic information like replacing the filter, UV bulb servicing, and user operation is clearly explained.

After unboxing my new purifier I reviewed the instructions and found the owner’s manual to be very clear and helpful. It is provided in English, French, and Spanish. At only 20 pages long, it’s fairly concise, but it’s good. The manual tells you the basics you need:

  • How to operate your purifiers
  • The indicator lights (power, air filter replacement reminder, and UV light bulb replacement)
  • Replacement filter model specifications
  • Power consumption
  • Specifications: size, weight, and square feet coverage

The English section is very clear and helpful. It contains 12 pages of information you’ll want to review before operating it, but honestly? This model is so easy and hassle-free to use you won’t need instructions though, honestly!

Don’t worry, I won’t leave any of the specifications off – I’ll provide them below.

(If you like, you can download the GermGuardian AC4825 manual here for your convenience)

Noise levels during use

The manufacturer claims that the unit has low noise during use and in my testing I found it to be mostly true.

  • Low speed (#1) is indeed fairly quiet, and suitable for sleeping if you’re a light sleeper like me
  • Medium (#2) is not very loud. It’s hardly noticeable at all if I’m watching YouTube or listening to music
  • High (#3) has a moderate level of noise and can be masked by the sound of your TV or radio. However, it’s fairly noticeable but not loud.

The high setting is especially helpful for fast and maximum cleaning of contaminated air. Smoke, dust, and more come to mind.

It’s honestly very quiet and I’ve found it pleasant-sounding when in use. While not as quiet during low-speed like a few competitors such as the Levoit LV-H132, I’m happy with it.

The main reason that the AC4825 is a few decibels louder is that it has not one but 2 fan sections and produces a bit more sound. Two fans move much more air than 1 and therefore, of course, add a little bit more noise than one alone.

That’s a trade-off when using a more powerful purifier like this.

Volume measurements

dB noise level meter measurement image

I measured volume levels using a nice digital decibel sound level meter at 1 meter (3.28 ft) from the purifier.

Measurement/SpeedVolume (dB)
Off (room noise)39.3

A note about the sound while running

I do have one minor gripe: while in operation, and although it’s fairly quiet, there’s a characteristic sound these devices produce.

Because of the dual-fan section design as well as both the motor and its electrical drive, the combination of these factors causes it to produces a “whirring” noise while in use. The noise isn’t annoying or bothersome in my opinion, but it’s something to be aware of beforehand.

Night brightness

Image of GermGuardian AC4825 in dark

The top-facing power-on LED is a green soft-glow type of indicator. It’s not too bright, but still slightly noticeable in the dark. The blue glow is produced when the UV-C feature is switched on isn’t very bright, but the human eye is more sensitive to blue light.

For that reason, my opinion is that for many people it will be fine, but if you’re especially sensitive to light when concentrating on a task on sleeping it could be an issue.

In that case, I recommend leaving the UV turned off during those times or moving it out of the way where you can’t notice it.

Not to worry though: the light brightness isn’t enough to “light up a room” or something unacceptable like that. Instead, it has a soft glow that’s not a problem in my opinion.

The AC4825 vs AC4900CA – A cool looking twin worth checking out

germguardian ac4825 vs ac4900ca image

The AC4825 (left) has a cool-looking twin, the AC4900CA (right). It’s identical in features and performance. Interestingly enough, sometimes one model is priced lower than the other and you can save a few dollars!

You might not know this, but the AC4825 has a sibling called the AC4900CA, which is identical in performance, features, and specifications.

I’ve thoroughly compared the two here: GermGuardian AC4825 vs AC4900CA.

I’ve seen it sold for a few dollars less (for example here at Amazon) and I think the styling is nice.

It’s well worth considering, as while not as popular as its counterpart it has the same great quality and is otherwise identical.

AC4825 vs AC5000 comparison

GermGuardian AC4825 vs ac5000 comparison photo

The “big brother” to the AC4825, the AC5000E is nearly identical except for room size coverage and the UV-C bulb. It’s a great addition to your home as well. Be sure to check out my detailed comparison if you’re interested in the AC4825 but have a large room!

In case you’re not familiar with it, the AC5000 is almost identical except for its size (near 28″ tall) and better room coverage. It too is an excellent large-room air purifier and is recommended for rooms up to 193 square feet in size (med.-large).

Just like the AC4825, it features a UV-C germ killing feature although the bulb design is different. I’ve enjoyed owning one so much that I wrote a detailed comparison of the AC4825 vs AC5000 here.

GermGuardian AC4825 vs the Honeywell HPA100

Honeywell HPA100 air purifier image

The closest rival to the AC4825, in my opinion, is the Honeywell HPA100. It offers some features the GermGuardian doesn’t, although it’s lacking in a few areas. It’s also available in a white version. Room size coverage is 155 sq. ft.

In my opinion, the AC4825 is a solid, well-built, and easy to use purifier. However, there’s no shortage of competition. Although it can’t come close to the popularity of the AC4825, the Honeywell HPA100 is a solid contender with about the same room size coverage.

As I’ve reviewed several other Honeywell models like the HPA160 you see here, I can’t verify their quality and they’re pleasant to use.

Some of the features the HPA100 offers that the AC4825 doesn’t are:

  • Electronic touch controls
  • A Turbo high-speed setting
  • Auto-off timer

However, there’s no germ killing feature offered. That’s absent in the Honeywell HPA series of purifiers, and it’s a shame. You’ll also pay a few dollars less for the GermGuardian model as well.

Additionally, the pre-filter in the HPA series is a little bit more thin than the GermGuardian family uses. The touch controls of the HPA100 are nice to have but to be honest, I’ve haven’t missed them at all.

I still use my AC4825 regularly and find it so simple and easy to use…it’s still one of my favorites! However, if having an auto-off timer is an important feature for you, it’s worth your while to check out the impressive reviews for the HPA100 at Amazon today.

Review summary

Honestly, I’ve got very little to complain about with the AC4825. It cleans the air well, it’s extremely simple to use, and it’s quiet. I love it!

The AC4825 makes enjoying clean, fresh air easy and affordable.

Image of AC4825 with Editor's Choice award badgeWatch out for high prices, however! Head over to find the current sale price (and get free shipping!) at Amazon.

  • Quality - 9.2/10
  • Value - 8.9/10
  • Ease of use - 10/10
  • Air cleaning ability - 9/10
  • Features - 7.5/10
  • Noise levels - 8.8/10

A well-performing air purifier that you'll be glad to own. No wonder it's one of the best-selling models today.

The GermGuardian AC4825 is a no-frills tower air purifier with simple operation and good air cleaning ability. It lacks a few fancier features when compared to more expensive models, but it’s a better value. Room coverage (med. rooms, 155 sq ft) is better than many similarly priced competitors.

Quality and build are very good; maintenance is easy to perform. It’s a quiet and pleasant-sounding purifier in my testing. The prefilter/HEPA filters work well to remove airborne particulates and odors. The UV-C feature is a bonus germ-killing option. One of the best-selling air purifiers available today, it’s a solid, sensible choice for fresher air.


  • Great air coverage for its price range
  • AHAM Verified & Energy Star Certified
  • True HEPA filter + prefilter/carbon filter
  • Easy to operate
  • UV-C feature kills germs
  • Carry handle built-in
  • Filter & UV replacement reminders
  • 3-year warranty
  • Maintenance is easy to perform
  • Low operational noise
  • White version available
  • Prefilter/carbon filter separately replaceable


  • UV-C feature has no memory feature
  • No auto mode or auto-off timer feature
  • Blue glowing trim could be noticeable to some with high sensitivity
  • Tall height may not be suitable for all users
  • Rotary manual control fan speed switch
  • You’ll need to buy 3rd party filters to save money as originals are more expensive

Do Air Purifiers Work With Windows Open? There’s More To It Than You Might Think!

Image of a view of a garden with house windows open

Air purifiers work by circulating and filtering contaminants like microbes, allergens, pet dander, and many more from the air. At the same time, letting in fresh air is something most of us enjoy doing from time to time. But does it affect how your air purifier works?

You may be asking yourself, “Do air purifiers work with windows open?” To help you understand the facts more easily I’ve put together some helpful information to explain it all.


Answering the basic question – Do air purifiers work with windows open?

Air purifier open window facts

Technically speaking the short answer is –yes, but not as well as they should. Before we go any further, let’s consider what the word “works” actually means.

It’s important to understand that air purifiers work by continually cycling the air in a room and filtering it.

If you open windows, the process is interrupted and your air will be subject to whatever particles are present in the outdoors. Before opening the windows, consider that you’ll potentially be starting over with the air purification process, as the purifier will have to clean the room’s air all over again.

It depends mainly on what you’re cleaning from the air and how much outside air you let in.

Let’s use an example. Think about how a refrigerator works. Its primary task is to cool air inside of it, right? Likewise, an air purifier primarily filters out contaminants from the air around it that cause air quality issues.

If you open a refrigerator, will it still operate? Yes, definitely.

The same goes for an air purifier you’ve got running and cleaning the air in an open room. If you leave its door open, it will still try to cool the air near it as much as possible.

Likewise, an air purifier will draw in as much air is physically possible and filter it.  The performance in a room with windows open is much less than with windows closed.

The problem lies with efficiency.

Should I never open a window with an air purifier running?

No, that’s not the case at all. Basically, you need to think about a few factors before doing so. Ask yourself these questions:

#1. How clean is the air outside near the window you’ll have open?

Is it dirty, polluted, or smoggy? Is anyone burning piles of leaves nearby, for example? It’s a big thumbs down if your outdoor environment is full of smoke, trash, and particles you don’t want indoors!

I’ve lived in ground-level apartments very near the path of passing cars in the past. In some cases having the window open wasn’t a problem. However, some cars with emissions problems or diesel pollution would enter my residence.

#2. Will you remember to close the window later, or do you plan to leave it open for hours? (Will you forget to close it?)

Time is the determining factor for whether or not an open window will or will not reduce the indoor air quality where you live. And your air purifier’s efficiency as well.

The longer the window is left open, the less work that the air purifier can perform. It takes a number of hours to fully clean the air in a standard sized room. Think about how much longer the device will take to do so in the case of having that interrupted.

If a room has air blowing in from outdoors it will still circulate the air and filter it, but because of the disturbance in the airflow the air to get cleaned which is the outside air.

Unfortunately, leaving the window open means the air purifier is not just cleaning the air in the room. It must also clean the air entering the room from the outdoors as well.

As long as that condition is present, you’ll never have fully purified air inside.

Diagram showing air purifiers working with windows open

An air purifier can “work” with the windows open, but it can’t work nearly as well as it would with the room sealed. One significant problem is that contaminants like allergens are re-introduced into the room’s air. It will take much more additional time to complete the purification process. If a window is open, there will always be air containing outside particles.

5 factors to consider before opening a window

Outdoor air pollution facts image with percentages of pollutants
1. Your outdoor environment

I don’t recommend opening windows if you live in a polluted area or one that has car exhaust, smoke, or other pollution issues nearby. Also, definitely don’t leave the windows open during spring because of the high pollen count. That stuff gets everywhere and will consume your air purifier’s filter lifespan more rapidly.

Opening windows means that you’re not just giving the air purifier work additional work to do. You’re also prolonging the time it will take for the air inside your house to be thoroughly cleaned.

For those with allergies, a few seconds of exposure to allergens can be critical. I don’t have allergies but I can feel the effects of pollen & other pollutants in the air. Vehicle exhaust can cause lots of coughing and headaches from time to time. Dust is another issue to contend with, too, and it gets all over the place after a few weeks!

For the sake of your health and quality of living, open the windows only if you live in a relatively clean environment.

2. Your home’s indoor environment

Image of smoke from cooking in kitchen on stove top
Given that you own an air purifier, it’s safe to assume the cleanliness of your indoor air is (now) probably pretty good. Otherwise, something else must have prompted you to open the window.

I totally get it – lots of things can happen. Maybe you burned your cooking and need to let the smoke out FAST! Maybe the garbage has piled up because of a rough week at work & you didn’t have the time. Painting your walls and having to deal with the fumes is another potential reason.

These are honestly all great reasons – you don’t have to have some huge, major cause for opening one or more windows. I love opening windows in the summertime and hearing the kids play outside. It’s one of life’s little pleasures, and I still have fond memories of living nearing a playground many years ago.

An air purifier will keep doing its job, regardless of whether the room is sealed or not.

If you’re like me and live in a fairly nice area with mostly fresh air, the air inside your house should stay clean and filtered as long as an air purifier is at work.

To make the most of your air purifier, keep the time you have windows open to a minimum.

3. The impact on your air purifier

Image of Levoit LV-H132 air purifier in bedroom

Fact: It’s easier for an air purifier to work within confined spaces.

After all, disruptions are minimal. It pulls in air, filters it, and releases it back to the room as fresh, clean air.

The air that it filters is some of the same air it filtered a few minutes ago, and the number of particles that get trapped in each filtration process decreases per attempt.

When you limit the amount of air an air purifier has to clean, you greatly increase its efficiency and the amount of time it will take to freshen an entire room.

However, there’s another issue you might not have thought of: if you’re cleaning additional air from the outdoors, that means you’ll be decreasing the life of the air filter. That’s something to think about.

4. Energy costs

Because of the open window, clean air will exit and unfiltered outside air will enter. When this happens there’s a good chance you’ll be tempted to turn up the fan speed and let the device run for more hours than you normally would.

While it’s not a huge amount of electricity to be consumed (most of today’s small & efficient models like this one one consume 10 watts or less) it can add up over time and is unnecessary.

Less effectiveness = you notice the air isn’t clean = you use your purifier more. That adds up to more money wasted!

5. Time

Image of a digital alarm clock radio showing time 4:00 PM
As I mentioned earlier, the amount of time it takes for an air purifier to fully freshen a room is affected by air space. Take my advice and close the window after a few minutes.

It’s not just whether or not a purifier can work with windows open, but if you are dealing with respiratory problems it can be pretty important. The amount of time you suffer from a lower-quality air environment is directly impacted by how long you will have to keep it running.

In most cases, it only takes a handful of hours for your air quality to greatly improve. Your quality of life can improve accordingly! Severe conditions like cigarette smoke and multiple pets with odors & their dander are some good examples.

How long do you want to prolong having the best, freshest air possible?

Of course, if health problems like asthma and emphysema aren’t an issue, then that’s not really a concern. My goal in bringing this up was to at least give you some food for thought so you can make the best decision for you & your family.

Air circulation factors to know

Diagram of room air flow with windows open air purifer

Airflow with 1 vs 2 or more windows open can be dramatically different. With 2 or more windows open, often the air purifier will have almost no effect. With only 1 window open, there is some external air entering the room but the purifier can at least work with marginal efficiency. This is because the amount of disturbance in the room’s airflow is typically much smaller.

If you do decide to open windows, try opening only one in each room. The reason is that 2 or more windows tend to allow more airflow through a room but the drawback is the disturbance in the air around the purifier. Basically, you defeat the purpose of using a purifier when doing so.

Perhaps you occasionally enjoy listening to the lovely sounds during a warm summer’s night. Wait until your indoor air has been freshened then open only one window. You’ll find it will have minimal impact on the indoor quality where you live in most cases.

Final thoughts and advice to take away

You SHOULD open your windows if:

  • You’ll close them relatively soon or you don’t have immediate health or allergy issues
  • Your outdoor environment is relatively clean
  • Your room is newly painted or fumed
  • There are immediate extreme air quality problems like from a kitchen fire, burns, or garbage, etc.
Note: If you inhale too many Volatile Organic Compounds (VOCs) – a harmful chemical common in paint – be sure to open your windows and not stay in the room for too long. Read more about the symptoms of VOC poisoning here.

You SHOULD NOT open your windows if:

  • You plan to leave them open for extended periods of time
  • Your outdoor environment is heavily polluted
  • You still have air quality issues indoors and the purifier hasn’t completed cleaning it
  • You have significant indoor air quality problems like smoke, pet dander, etc that require additional time to treat

Essentially, there’s no harm in running an air purifier with windows open, but it’s not helpful and you’re better off turning the purifier off while the windows are open.

Simply put, in most cases, it reduces the ability of your air purifier to work as well as it can.

Here are some basic guidelines to remember:

  • Have a heavy source of air problems? (pets, cigarette smoke, etc.) Consider leaving the windows closed
  • Avoid keeping the windows open if you live near a heavily polluted area or during times like spring
  • Ideally, wait until a room has been freshened and the major contaminants have been removed first before doing so
  • Ideally open only ONE window, as it reduces the amount of air from outdoors and the air disturbance created

Now that you’ve learned more, how about some additional help in finding the best air purifiers for your money? I’ve put together a buyer’s guide and a list of some of the best air purifiers under $100 here.

Are Air Purifiers Also Fans? Clearing Up A Common Question

Honeywell air purifier in a kitchen

If you’ve been around an air purifier before, you probably already know that most move air. And if they move air, it’s easy to see why you might wonder if air purifiers are also fans.

Not only will I answer this question but I’ll also show you how air purifiers work.

You’ll also find out a bit more about a few that actually do act like fans as well!


The basic question: are air purifiers also fans?

The general rule is “No.” Air purifiers aren’t fans alone. That is, while they do move and circulate air, most can’t do so with the high speed & larger airflow of a basic electric fan.

More importantly, they’re designed for cleaning the air you breathe which in turn makes a large impact on the airflow volume they can offer.

Standard electrical fans don’t have the same restrictions caused by doing other work like an air purifier does. Because of that, ordinary fans can blow air much faster to cool you and the room you’re in.

Read on and I’ll explain why they’re not fans.

First, let’s talk about what a fan is and then what an air purifier is. I’ll then compare the two and explain specifically how they’re different.

What is a fan and how does it move air?

Diagram of axial and centrifugal electric fans

Electrical fans come in different styles and serve different purposes. Both use an electric motor to rotate blades which cut through the air and cause it to move from one side to the other, creating airflow. Both centrifugal and axial style fans are used in air purifiers. You may have seen axial fans used in your desktop computer case. The curved blades on a fan cause the motion of air that is so important.

A fan is a device with fixed blades (usually curved) that force nearby air to move from the rear to the front of it in a blowing motion. It’s a common misconception that a fan cools air because it actually doesn’t. Instead, it moves air to create the opportunity for cooling by the evaporation of sweat and convection in an environment.

In other words, fans move a liquid or gas (air) rapidly to allow cooling to occur on you or an object.

Normally they’re powered by an electrical motor that uses many windings of copper wire to produce movement and turn the blades. This is done by allowing electric current to pass through the windings which then creates magnetic fields.

These fields, in turn, push away from other magnetic fields and the rotor, the rotating center section, turns. The fan blades, attached to the rotor, then cut through the surrounding air and the air is forced to move.

Typically the fastest fans have the greatest flow of air.


Sweating is how your body self-regulates its temperature. As your sweat evaporates, your body cools off because it requires heat to convert water to vapor. In still air, however, it isn’t so easy for sweat to evaporate. The air circulated by a fan helps the sweat on your skin to evaporate faster.

That’s why you feel cooler when there’s a fan blowing around you or on you.


Aside from helping regulate heat by helping your sweat to evaporate, fans also have a role to play in a process called convection. For our purposes, we’ll consider this process as heat moving away from one place to a cooler place. When you feel hot and the surrounding air is cooler, your body cools down by transferring heat to the air.

Air becomes less dense and rises at it’s heated. When you have a fan in the room, it helps to carry this warm air away. Cooler and denser air will settle down and the cycle continues, making you feel cooler.

Fans are generally designed to blow air as I mentioned above, although some fans are designed to suck or pull air. Some examples exhaust fans, vacuum cleaners, and range hoods (like you’ve seen in restaurants or perhaps in a home kitchen).

We’ll leave fans here for the moment and take a look at air purifiers.

What is an air purifier? How does an air purifier work?

Diagram illustrating how an air purifier works

Air purifiers work by moving air through filters and trapping airborne elements that cause pollution, allergies, asthma, sickness, and much more. Additionally, with an active carbon filter (a separate type of filter) they can trap odors and airborne chemicals. Some products like this GermGuardian AC4900CA also include a germ-killing feature using ultraviolet (UV) light.

An air purifier is an electrical device that eliminates airborne pollutants in a room.

Most air purifiers contain an electric fan which pulls air to the intake part of the device. Air is then forced through a series of replaceable filters where pollutants are trapped. After the air is cleaned it’s released back into the room.

As the process continues the air purifier will continuously cycle and filter bad elements and odors in a room. The result is fresh, clean, healthy air being left behind.

Air purifier filter types

Image of a GermGuardian AC4100 showing HEPA and activated carbon filtersA small air purifier (GermGuardian AC4100) showing the dense HEPA filter (white) and the activated carbon pre-filter (black). These work together to remove foreign particulates and substances like odors from the air. Neither can work alone to do both functions.

High-Efficiency Particulate Air (HEPA) filters are made of very thin entangled glass threads that are formed into a flat sheet, which is pleated like an accordion. Think of it as being an extremely dense material with gaps far too small to see with the human eye.

This material works to filter & trap 99.97% of airborne particulates and allergens as small as 0.3 microns (that’s 1/1,000,000 of a meter in size).

Activated carbon filters are often used along with HEPA filters because of their porous nature which makes them highly effective at absorbing volatile organic chemicals, odors, and some gases in the air. They may or may not be a part of an air purifier that you buy.

It depends on the design of the product.

Pre-filters are usually made of washable foam or nylon materials that trap larger particles. These are often integrated with HEPA and carbon filters so as not to overwork the more expensive filters. They’re typically a less dense and thinner filter serving mainly just to trap larger elements in the air like dust, insects, hair, and so on.

They’re generally used as a 1st stage in the filtering process if provided.

Aside from different filters used, there are also different types of air purifiers. Some use ultraviolet light (UV) rays to destroy mold, mildew, viruses, and other germs in the air as they pass by. There are also ozone-generators and negative-ion air purifiers that remove microbes and gases but produce ozone molecules as a functional by-product. Ozone-producing air purifiers are not approved by the Environmental Protection Agency (EPA).

So, are air purifiers also fans in a way?

AC4825 rear motor and fan illustration
Air purifiers contain electric fans which are used to draw in dirty air and blow out clean, filtered air. The pink arrows in the image point to the centrifugal fans used in this GermGuardian AC4825 purifier. In the center you can see the silver electric motor used to drive them both.

As I mentioned at the beginning of my post, it’s important to understand the difference between a regular fan and an air purifier.

1. Unlike fans, the majority of air purifiers have filters that greatly slow the flow of air through them.

That’s why they’re not capable of moving enough air to cool you or your room. The rate depends upon the purifier’s fan speed in use and efficiency.

These two products are not the same because they’re designed and made for different purposes.

The way they operate is different, too. They’re similar in the sense that both cause the air in your room to circulate. Fans circulate air in a room as a side effect of how they work – often they’re used to blow air directly.

Air purifiers, on the other hand, filter airborne particulates and circulate the air as they go through the dynamics of air purifying. Air circulation, rather than blowing air directly in any particular direction, is critical to how they function.

2. Most purifiers aren’t designed with fans that can move enough air to cool a room.

Purifiers aren’t expected to clean all the air in a room rapidly. It can take anywhere from several hours to a few days depending on the product and the room size. Air purification is a process that takes time.

If you require something that was much faster, it would be much larger in size and more expensive. That isn’t practical and very few people would be willing to pay for that.

There are also some types that don’t have fans. These products don’t add to the normal circulation of air in a room, and thus don’t have the added function of a fan. Ionizers and some ozone generators are good examples of this type.

Examples of air purifiers that are fans

Image of air purifiers that are fans
There are a few exceptions to the rule. A few products on the market actually do act as fans. The Honeywell AirGenius product family (left) and Dyson air purifiers like the Pure Cool purifying fan (right) create a very high airflow in a room much like a fan.

While what you’ve read is true for most, there are a few exceptions to the rule. Some products like the Dyson Pure Cool purifying fan are designed specifically to move large amounts of air to help keep you cool & comfortable.

Others like the Honeywell Air Genius 5 have a different type of filter design which allows a high rate of air to blow just as a fan (and even oscillates to blow air like a fan).

In conclusion

Most air purifiers are not, in the most strict sense, fans. They can’t move large amounts of air rapidly like fans and cannot cool you or your home. There are a few models, however, that are exceptions to this.

Unlike a fan, the typical air purifier:

  • Can’t produce high-speed airflow – the filters inside greatly reduce it
  • Won’t cool you or the room, as the airflow doesn’t extend very far past the purifier
  • Needs a lot of time to circulate the air in a room

As most air purifiers work, they do circulate the air in a room, which is the function of a fan. So in that respect, they do work as fans. But we draw the line there because an air purifier is more than just a fan.

If the ability to cool a room is important to you, plan on purchasing a fan separately. You can, in most cases, use a fan in the same room with an air purifier without any problems!

Hopefully I’ve cleared up the question for you and helped you better understand the differences.

Wondering if you can use a purifier with the windows open? Here’s a helpful post I wrote to answer the question about air purifiers and open windows.

GermGuardian AC4825 VS AC4900CA Hands-On Comparison & Details

germguardian ac4825 vs ac4900ca image

In my comprehensive comparison of the GermGuardian AC4825 vs. AC4900CA I’ll cover the specific differences and help you decide which one fits your needs better. If you’re shopping it can be very confusing when comparing these two wonderful models.

Believe me, I understand how it feels!

I’m a proud GermGuardian owner myself so I’ve decided to share my first-hand knowledge with you after personally owning and testing both.

Both models have some good and bad points as they’re from the same basic design family. Let me tell you up front – don’t worry! They’re both great choices and well worth the investment.


GermGuardian AC4825 VS AC4900CA – Getting started

germguardian ac4825 vs ac4900ca confused guy and tablet

With a huge number of similarities shared between them, it can definitely feel a bit confusing and possibly even a little bit frustrating when trying to compare the two models.

Sadly, GermGuardian doesn’t make the differences clear and they certainly don’t make it easy to compare the two in terms of design and performance aspects.

To make matters worse, the owner’s manuals are slightly different and don’t clarify things.

For example, the AC4825 owner’s manual lists several specifications that aren’t listed in the manual for the AC4900CA. In order to make things more clear I’ve gathered all the specifications and arranged them in a way that’s easy to compare.

GermGuardian AC4825 VS AC4900CA: Comparing specifications

Let’s get the basics out of the way. Here’s a side-by-side comparison of the features and specifications of each. I’ll go into more detail about the similarities and differences between the two afterward.

germguardian ac4825 vs ac4900ca side by side in living room

AC4825 Specifications
  • Room size rating: 155 sq. ft (medium room)
  • UV-C germ killing light
  • Titanium Oxide odor molecule remover
  • 3-speed fan control
  • True HEPA filter w/ activated carbon filter
  • CADR Rated 101+ (Clean Air Delivery Rate)
  • Low-noise fan setting
  • Replaceable UV bulb
  • Dual-section blower fans
  • Simple rotary control
  • Pushbutton on/off UV switch
  • Filter replacement reminder
  • UV bulb replace indicator: Illum. trim
  • 3-year limited warranty
  • Replacement filter: FILTER B (FLT4825)
  • Carrying handle
  • Weight: 8.65 lbs
  • Cord length: 6 ft.
  • Control location: top
  • Size: 6.75 x 10.25 x 21.5″
AC4900CA Specifications
  • Room size rating: 155 sq. ft (medium room)
  • UV-C germ killing light
  • Titanium Oxide odor molecule remover
  • 3-speed fan control
  • True HEPA filter w/ activated carbon filter
  • CADR Rated 101+ (Clean Air Delivery Rate)
  • Low-noise fan setting
  • Replaceable UV bulb
  • Dual-section blower fans
  • Simple rotary control
  • Pushbutton on/off UV switch
  • Filter replacement reminder
  • UV bulb replace indicator: LED (front)
  • 3-year limited warranty
  • Replacement filter: FILTER B (FLT4825)
  • Carrying handle
  • Weight: 7 lbs
  • Cord length: 6 ft.
  • Control location: front
  • Size: 8.875 x 7.125 x 21.75″

As you can see, these are essentially the same unit. Both share the same great features and performance that make the AC4825 so popular.

It’s one of the best-selling air purifiers today – check out the amazing number of buyers over at Amazon, for example.

Both purifiers perform well and there’s no noticeable difference in air cleaning quality. And there certainly shouldn’t be; they both use the same exact filter.

It’s pretty cool to see (or should I say, smell?) how quickly they remove odors like those from burnt matches in the room where I tested them.

Build quality & styling similarities

Both the AC4825 and AC4900CA feature the same design platform. They’re made of similar internal components right down to the control board, motor, and the general design.

Both are well-constructed, housed in a strong ABS plastic body. The units are both operated with an easy-to-turn (but not flimsy) rotary fan speed control switch. The UV germ-killing feature, activated by an on-off button, feels solid as well.

Note that if the unit is turned off when the UV feature is on, you’ll have to turn the UV option on once again the next time you use it. There isn’t a memory feature for that.

For convenience, as both models are extremely similar in design, I’ll use some images and descriptions from the AC4825 to illustrate and explain more about both models.

The sibling purifiers use a single electric motor driven by a solid-state speed controller. The electric motor is connected to not one but two fan assemblies which resemble cylinders with fan blades.

AC4825 rear motor and fan illustration

The pink arrows indicate the top and bottom fan assemblies in the purifier. Two are used together to drive more airflow with more efficiency. The electric motor (pictured, silver object in the center) drives both. (AC4825 shown – AC4900CA is identical)

And before I forget, both also have a built-in handle at the top rear. It’s actually very handy as while the air purifiers weigh a bit under 10 lbs, they’re rather tall and cumbersome to carry. This makes it easier in my experience.

AC4900CA styling similarities

While the AC4900CA may seem unusual and you may be asking yourself, “Why did they make this one?” GermGuardian actually produces quite a few different products and the air purifier line also includes the smaller sibling called the AC4100.

It’s like the little brother to the AC4900CA and a great little small room air purifier. It covers about 89 square feet of room size vs. the 155 of the AC4900.

GermGuardian AC4100 angle view

The GermGuardian AC4900CA actually shares its same cosmetic design and features with its smaller sibling, the AC4100 shown here. I prefer the style. It’s a modern & contemporary design that really compliments what is already a great air purifier. It reminds me quite a bit of a home stereo loudspeaker.

It essentially boils down to your personal preference in styling. However, one thing to bear in mind is that there isn’t a similar smaller version of the AC4825 like there is of the AC4900CA. Why does that matter?

Because if you’re planning to add more purifiers in order to clean the air in your whole house, you won’t be able to have a matching set unless you use the AC4900CA and AC4100 instead of the AC4825.

Size, performance, and noise levels


Size-wise, there’s very little difference. Both are just under 22″ in height. There is about an extra .25″ height with the AC4900CA. The AC4825 measures 6.75 x 10.25 x 21.5″ while the AC4900CA comes it at 8.875 x 7.125 x 21.75.”

Therefore the AC4825 is actually a bit oblong as it is shaped with a bit more of an ellipse shape, depending on how you look at it.

Personally, while I love both models, I lean towards the style of the AC4900 because it’s slightly closer to being square in shape.. That’s completely a matter of personal preference.

The flat front grill looks very nice to me. In either case, you’ll need to make sure you have sufficient room wherever you plan to use it due to the tall height.

Ideally you’ll place either in an area where airflow isn’t restricted. The front and back, where air exit and enter respectively, should have 1-2 feet or so of free space to ensure air can flow freely.

Image comparing AC4825 vs AC4900 side by side

Performance and noise levels

After digging in and evaluating both, I was able to see just how similar the two models are. Not only do both share the same design, good performance, and features, but they also share the same “whirring” noise I’ve known about for a long time that the AC4825 has when it’s in use.

While not a bad thing exactly, it’s a characteristic of these “tower” style air purifiers. It’s due to both the electric motor system as well as the 2-rotor fan design. The electric motor in both purifiers produces a slight “whirring” sound with a little bit of an undertone, so to speak.

It’s largely due to the motor being driven by an electronic solid-state motor controller which rapidly switches the electrical power to the fan on and off to maintain a fixed speed.

I say that to make you aware that neither model is perfectly silent on the lowest setting, although they are both very quiet indeed. Unless you’re the lightest sleeper like me, the low setting is very quiet and both operate with low noise. 

Volume measurements

I carefully measured volume levels using a great little digital sound level meter at 1 meter (3.28 ft) from the purifier.

Measurement/SpeedAC4825 Volume (dB)AC4900CA Volume (dB)
Off (room noise)39.339.3

They’re basically identical in fan volume, as you can see (it tends to be a bit higher when they’re new and haven’t fully broken in yet). Both are very quiet on the lowest setting! That’s similar to another competitor in their price range, the Levoit LV-H132.

Maintenance parts & cost

Image of GermGuardian AC4825 and AC4900 replacement bulb and HEPA filterThe germ-killing ultraviolet light (UV) bulb (left) and the replacement HEPA filter with activated carbon filter section (right) are the same for both models. Expect to spend around $25 for the bulb and somewhere between $30-35 for the filter.

The GermGuardian Filter B (FTL4825) serves as the replacement for both models. Additionally, the UV bulb (the LB4000) is the same as well. You don’t have to be concerned that buying one model means paying more when it comes time to replace the filter or bulb.

In this case, there’s no difference.

You can expect roughly 6-9 months of use from the filter before replacement, although that varies with use & needs. Heavier conditions and heavy odors or substances in the air will shorten the life.

Likewise, for low-demand conditions like in my home, you can expect the filter to last longer.

Checking the filter

You’ll still need to check the filter manually and reset the filter replacement reminder yourself, as there’s no way for the purifier to know how soiled the filter is.

That’s not a feature available in products at this price point.

Filters can be replaced as a set (HEPA filter + the carbon filter section) or you can also replace just the carbon filter if needed. That’s especially helpful if you have pets, cigarette smoke, or other odor-causing contaminant sources which will eventually be absorbed by the carbon filter and will require a replacement to restore the effectiveness of it.

The good news is that you can help extend the life of the prefilter by brushing off debris buildup or vacuuming (which I do and recommend).

Room size coverage

Both models are technically specified as providing 155 square feet room size coverage which is just above the space provided by a 10 x 15 foot room. Note, however, that GermGuardian lists both models as covering a “medium sized” room.

Additionally, plenty of other owners report using it in larger rooms and even their living rooms with great success.

Don’t let room size specifications discourage you in case your room is a bit larger. For a good quality air purifier with great airflow and adequate ventilation, it’s possible to clean the air in a somewhat larger room well. You’ll need to give it additional time to do so but it will.

The main thing is to understand that air purifiers work by cycling air and filtering it. After some period of time all of the air in a room will have been filtered and cleansed.

Filter and bulb indicators

Filter replacement reminder

For both models, the power light (a soft-glow LED) is normally green during standard operation. It will turn red and flash as an indicator when the filter needs to be checked and possibly replaced. You’ll need to reset the reminder which is very easy to do by simply pushing and holding the UV control button for 5 seconds.

UV bulb replacement

One area where the two differ is the UV light bulb replacement indicator. The manufacturer estimates replacement life at 10-12 months, although a few owners have reported earlier bulb failures. Generally speaking, however, you can expect good bulb life as it’s a low-power bulb at only 5W.

Therefore it’s not excessively hot like incandescent bulbs.

GermGuardian AC4825 top side view

On the AC4825 the blue glowing trim (which is the light glowing when the UV-C option is in use) will blink continuously when it’s time for bulb replacement. On the AC4900CA, which doesn’t have a similar glowing trim, the UV-C indicator LED will turn red. In both cases, you’ll need to reset the reminder using the UV button after bulb replacement.

The AC4825 indicates it’s time to replace the bulb by continuously blinking the blue light/trim on the front, while the AC4900CA does so by the UV-C indicator light turning red when it is time.

I was surprised there was this minor difference, but given how the AC4825 allows the UV-C bulb to glow through the trim for a stylish effect and the AC4900CA does not, it does make quite a bit of sense.

GermGuardian AC4825 and AC4900CA blinking light summary

Here’s a simplified chart to help you see the differences in the GermGuardian blinking light patterns & meanings.

Blinking Light TypeAC4825AC4900CA
Blinking blue light(UV-C glow trim blinking) UV bulb needs replacement(UV light blinking) UV bulb needs replacement
Red blinking lightFilter needs check/replacementFilter needs check/replacement

Filter replacement how-to

Filter replacement is identical for both and is one of the easiest to replace that I’ve ever seen! It’s just a simple matter of pulling down the release tab, removing the cover, leaning the old filter out, and leaning the new back into place. Then you simply hook the cover back into place (with the tabs at the bottom) and snap the cover back in.

You’re done! It takes all of about 10 seconds to do.

GermGuardian AC4825 filter removal image
Filter replacement is LITERALLY a snap on both the AC4825 and AC4900CA! Both are identical in how filter replacement is done. (Left) The cover is removed by pressing the release tab at the top, then after the cover is released the old filter can be removed (right). Installation is extremely simple and is just the reverse of removing the old one. I really like how easy it is!

Control differences

As I mentioned near the beginning, both models share similar controls. Actually, they’re functionally identical and are extremely similar cosmetically.

GermGuardian AC4900CA vs AC4825 controls image
As you can see, they’re extremely similar, with the AC4900CA (left) having a small LED for indicating the UV-C germ killing option power status and the AC4825 (right) does not. It does, however, use the illuminated trim to do this (see earlier section).

Both feature a power-on LED which, when green, indicates normal operation and turns red to indicate filter replacement should be checked. The fan speed control is superbly simple as you just switch it from the off position to speeds 1-3.

AC4825 VS AC4900CA Pricing – Is there a difference?

Yes, from time to time there is a difference in price despite their similarities. As prices tend to fluctuate up and down, it’s important to check the current pricing.

For example, here’s the current pricing as of this moment on Amazon (I’ll use the site as a great example since it tends to be more competitively priced and reflects supply & demand as well):

Current price:$89.99$83.33

(Current pricing updated on 2020-10-26 at 08:22 via Amazon)

They’re both great performers and are very well-reviewed. You can’t go wrong buying the cheaper model over the other one.

Final thoughts – GermGuardian AC4825 VS AC4900CA – Choosing the best one for YOU

To recap: both models are nearly identical and have only minor differences. Performance is the same – only a difference in style and where the controls are located. However, as you saw above, you can potentially save a few dollars if you shop smart.

I will note that if you’re very sensitive to light and are a light sleeper like me, the AC4900CA may be a better choice for you. The AC4825, with the glowing blue front trim, tends to illuminate the room a little bit at night.

Many times I’ve been asleep but woke up later and noticed the glowing blue trim on the AC4825 when the UV-C feature was in use.

To help you better make a decision, here’s a brief comparison chart the minor differences I’ve found in my comparison of the 2.

GermGuardian AC4825 vs. AC4900CA Basic Comparison Table

Germ Guardian True HEPA Filter Air Purifier with UV Light Sanitizer,...
Germ Guardian True HEPA Filter Air Purifier with UV Light Sanitizer,...
GermGuardian AC4825
GermGuardian AC4900CA
Room Coverage (Sq ft)
6.75 x 10.25 x 21.5″
8.875 x 7.125 x 21.75"
Difference Vs. Other Model
UV-C glow trim, controls on top, UV bulb replacement reminder flashes blue in trim
UV-C indicator is small LED, front-facing controls, modern style
3 yrs limited warranty
3 yrs limited warranty
Replacement Filter
Replacement bulb
Germ Guardian True HEPA Filter Air Purifier with UV Light Sanitizer,...
GermGuardian AC4825
Room Coverage (Sq ft)
6.75 x 10.25 x 21.5″
Difference Vs. Other Model
UV-C glow trim, controls on top, UV bulb replacement reminder flashes blue in trim
3 yrs limited warranty
Replacement Filter
Replacement bulb
Germ Guardian True HEPA Filter Air Purifier with UV Light Sanitizer,...
GermGuardian AC4900CA
Room Coverage (Sq ft)
8.875 x 7.125 x 21.75"
Difference Vs. Other Model
UV-C indicator is small LED, front-facing controls, modern style
3 yrs limited warranty
Replacement Filter
Replacement bulb

These are great basic air purifiers that work well and won’t let you down. Operation is very simple, the true HEPA and activated carbon filters work well, and the filter & bulb reminders are nice. The addition of a UV-C germ-killing feature is definitely a big plus. You won’t be disappointed!

If you’d like to know more see my detailed review of the AC4825 here.

If the AC4825 or AC4900CA are still too expensive for you, don’t worry! I wrote a great post with some affordable models all under $100.

Do I Need An Air Purifier In Every Room? An Informational Guide For Everyone

Image of a nice suburban home USA

So you’re considering buying an air purifier. But perhaps you want to breathe better, cleaner air in more than just 1 room.

If you’re thinking about buying more than one you may be asking yourself, “Do I need an air purifier in every room?

In this post, I’ll go into more detail and cover the facts you need to know before spending money. I’d like you to get the most benefit from your buying options and to get the best benefit per dollar spent.


Do I need an air purifier in every room? The basic answer

Before I go into more detail, here’s the short answer.

Air purifier room facts

The simplest answer is that you don’t need an air purifier in every room.  There are more things to consider, too, before buying & using air purifiers in multiple rooms:

  • The number of rooms which you regularly occupy and need an air cleaner for
  • Air quality problems you need relief for
  • Room size (in square feet) for matching with the correct model of purifier

However, you need to buy the right kind (or a combination of different kinds) for your needs. Additionally, you need to buy air purifiers with enough coverage for your particular home & needs.

You’ll also need enough of them to handle the air space volume (room size coverage, in other words) where you have air quality problems.

What to know before buying air purifiers

If you want the air inside your house to fresh and free of irritants, it only makes sense to place air purifiers in all rooms… right?

Well, not necessarily! 

Before making a decision, you need to consider several factors that affect the “hows” and “whys”:

  1. Budget
  2. Air cleaning needs
  3. Rooms needing coverage
  4. Air purifier room size

1. Budget

To be frank, placing an air purifier in every room would be pricey. From the very beginning, you really need to think about your expectations and air cleaning needs vs. the amount of money you can afford to spend.

While this may vary from home to home, the average house has about five rooms. How much are you able to spend to get air purifier coverage for your home and in multiple rooms?

Give this some thought before you go shopping online. Some people might be inclined to buy cheap ones so that they can place air purifiers in all the rooms. This is actually a mistake that might not seem obvious at first glance.

Cheap, low-spec air purifiers can actually be worse than having no air purifiers at all.

There are lots of reasons why, but it’s mainly because they do a poor job at cleaning the air and ultimately you’ll be unhappy with the results. In some cases, some products sold as “air purifiers” do little besides blow air and some produce by-products that can irritate the throat and respiratory system.

If you have to spend extra money later to buy better ones, that means you’re actually losing money – not saving it!

Cheap ones will only circulate dirty, unfiltered air through your house to the point that you would probably be better off without one. A single air purifier of good quality is worth more than several low-grade ones that work poorly.

Remember this: Quality over quantity. Every time.

What you can expect to spend

That being said, for a decent budget air purifier you can expect to spend about a bit under $100 for each.

Higher quality models that are best sellers and have amazing buyer satisfaction are only a bit more and sell for around $140-$200 depending on room size coverage, features, and performance.

More advanced models offer a lot more convenience and can even run in automatic mode or include a remote control.

Don’t worry! You don’t have to be rich or spend a ton of money to keep the air clean in your home. There are some great options that are affordable – you just have to be careful when buying. I’ll cover that more in detail below.

2. Your air cleaning needs

Diagram showing common air quality problem sources

A wide variety of contaminants – or combinations of those – need a “real” air purifier that will permanently remove them from your air. Some problems, like dust mites, require a HEPA filter. Odors and airborne chemical substances need an activated carbon filter to cleanse the air successfully. Think about what you specifically need relief from.

Not everyone has the same air quality needs. For example, if you have pets you’ll have slightly different requirements than someone who is dealing with dust.

A person with allergies or asthma problems, for example, will need different features as well.

Pet owners can sometimes find certain models with special filter versions available for their product.

Want to learn more? I’ve written a great post called “What Kind Of Air Purifier Do I Need?” here which goes more into detail.

Ultimately, it if involves removing odors, you need one that features an activated carbon filter. For general applications, at a minimum, you need a High-Efficiency Particulate Air filter (HEPA) model with sufficient room coverage.

Special features

If you have particular health issues or are susceptible to colds or other sicknesses, you might consider a model with a germ-killing feature. Some do this with an ionizer or ozone generator.

I don’t recommend these for people with respiratory problems, although ionizers are proven to greatly reduce airborne germs that cause sickness.

A few offer germ-killing features such as ultraviolet light (UV) light to reduce the chances of you contracting an illness.

Others offer advanced convenience features like self-off timers, a quiet mode, and so on. Some even offer smartphone control and air quality reports while you’re away!

3. Rooms needing coverage

Do you spend a considerable amount of time inside your house? Which rooms do you stay in the longest? Which rooms do you seldom use?

An average person spends the longest time in their bedrooms, followed by the living room. Most likely the time you spend in other rooms would pale in comparison. Air purifiers placed in rarely used rooms are useless so they would be a poor use of your money.

What’s the use of purifying the air in an area you don’t use? Don’t be concerned about rooms that are rarely entered. Much as you seldom enter them, so the same is true for air contaminants.

Unless some of the areas of your home have exposure to the outdoors (and particles brought inside) or other sources of poor air quality, it really shouldn’t be much of a concern.

Thinking about purifier placement

Concentrate mainly on adding air purifiers to the main areas – and areas in between – that you spend the most time in.

The areas where you, your pets, or others predominantly reside are the rooms that need air purifier coverage. Placing them in between means that other areas will have their air cleaned as well.

Although they’re rated for certain size rooms, air purifiers will still circulate air from other parts of your home. It does take some time, but additional rooms will have their air purified as well if air can circulate sufficiently.

4. Air purifier room size – how to find the square feet measurement

Room size measuring example

Most air purifiers sold specify the recommended room size they can clean in terms of the size of the room. This is usually stated in square feet (sq. feet, or “ft^2”).

Others may optionally state the room air coverage in cubic feet, which is very similar to room size except that it also takes into account the ceiling height of a room. Unfortunately, some may not specify this coverage ability clearly.

If a purifier doesn’t specify room size, assume it is generally good for a small room.

Before shopping, you need to estimate these rough numbers using some easy math. Don’t worry, as even if math isn’t your strong point, it’s not hard at all.

Estimating the air purifier coverage you need for a room - examples

1.  Estimating the air purifier coverage size in square feet for a bedroom:

Room width x room length =  10 feet x 15 feet room size = 150 sq. feet (150 ft^2)

2. Estimating the air purifier coverage size for a bedroom in cubic feet (air space volume):

Room width x room length x ceiling height = 10 ft x 15 feet x 15 feet = 2,250 cubic feet (ft^3).

After estimating the room size coverage you need, write it down in your notes. That way you’ll be ready before shopping when evaluating choices and you can verify it’s close to your room size.

Air purifier coverage specs are estimates

The room size listed by different manufacturers are estimates. Just like any other kind of estimate, it’s impossible to get the exact number – but the great news is that you don’t need to. The idea is to buy an air purifier based on the room size coverage it states it can provide that is close to the room or rooms you want to use it in.

Don’t worry about getting it perfectly right. All brands take time to circulate and clean all the air in a room, so even if the listed coverage is a bit below what the product you buy is rated at, it will clean it eventually.

Just remember it doesn’t need to be perfectly matched. Your goal is to buy a purifier with close to or greater than a coverage rating of the room you want to use it in.

Air purifier CADR ratings explained

What is a CADR rating?

A purifier’s Clean Air Delivery Rate is a measured, numerical way to express how effectively a purifier can filter a room’s air.  Introduced by the Association of Home Appliance Manufacturers (AHAM), the CADR rating is an industry standard for measuring the airflow of filtered air.

The main benefit of a manufacturer-provided CADR rating is that you know the purifier has been tested in a certified test lab by following industry guidelines.

In other words, the CADR rating is a figure of measurement that is the volume of filtered air delivered by an air cleaner. The higher the numbers (listed for smoke, dust, and pollen) the more effective it is at filtering.

Why it’s helpful to know

Generally speaking the higher the numbers or numbers, the better.

CADR rating example label

Shown: An example CADR rating from a purifier. Not all manufacturers provide them or only provide them for certain models (typically higher-quality models include them).

Products sold with a CADR rating benefit you because you know they have a proven amount of square footage air filtering coverage. There’s no guessing and it is a good indicator of a quality product with demonstrated filtering ability.

Higher ratings for the tobacco smoke, dust, and pollen numbers are a sign that the unit will more quickly purify the air than a similar unit with lower ratings.

If the ratings between are the same between two products then the filtering performance is the same.

Air purifier types: portable vs. whole house vs. wall-mounted

Levoit LV-H132 Vs Germguardian AC4825 comparison image

Examples of two popular portable (floor use) air purifiers. Floor purifiers are the most common and are often the best choice for most people.

“Whole house, portable, or wall-mount air purifiers…which one should I use?”

You’ll likely be faced with this question as you set out to buy an air purifier. It’s actually pretty simple, but it’s something you may need to think about in advance.

Portable models (used on the floor or a shelf) can be moved around as needed while whole-house systems cover the full interior of your home. Wall-mounted units are attached to walls and can be placed out of the way.

Here’s a general overview of their respective advantages and disadvantages:

Pros and cons lists for the general placement types of air purifiers

Portable (floor or shelf) air purifiers

  • You can move them from room to room
  • Ideal for those on a budget (You can buy one and bring it along as you switch rooms, even take it to work!)
  • If you buy a model with low space coverage it may not work well in other rooms
  • You could decide it’s a hassle to drag one along every time you switch rooms

Whole house air purifiers

  • Covers the airflow system of your entire house – especially larger interior spaces
  • Works as one whole system (It isn’t necessary to purchase several units)
  • Heavily reliant on the HVAC system
  • Expensive

Wall mounted air purifiers

  • User-friendly (Commonly controlled using a remote control)
  • Works as one whole system (Not necessary to purchase several units)
  • Requires an installation process
  • Fixed in place (If not installed optimally, it could be less efficient)
  • Not flexible in use

What type of purifier should you buy?

The best air purifiers use a true High-efficiency particulate air (HEPA) filter along with a pre-filter and odor absorption feature. These types are very effective at removing airborne particulates of nearly all kinds. Avoid ionizers and ozone generators sold as “purifiers” as many are ineffective and can even cause health problems!

It basically comes down to personal preference. However, generally speaking, most people buy a moderately priced portable model. Many of those available today provide great coverage and air cleaning ability. You can also expect good reliability and fairly low maintenance costs.

You’ll also want to buy a model with a true HEPA filter for the best air cleaning performance.

When getting ready to buy a floor model or HVAC/whole-house purifier product, buy one that works using HEPA filters.

Avoid ionizers and ozone generators as at the minimum they’re not very effective. In the worst case, they’re potentially harmful to your comfort and health. I’ve had several readers report they’ve had very bad discomfort, coughing, and irritation from HVAC products sold as “air cleaners.”

These were ionizers or ozone generators sold with fancy marketing terms, rather than good, quality design and performance.

A standard filter-based purifier can’t cause these kinds of problems, and are nearly always a much better buy, too!

Portable air purifiers are best for those:

  • With a smaller budget
  • Living alone
  • Who are new to purifiers or don’t want to deal with installation hassle & secondary expenses
  • Are renters or may sell their home later
  • Who want additional special features like Wi-Fi control and others

Whole house purifiers are best for those:

  • With a large budget
  • Living in a house with a pre-existing HVAC system
  • Willing to pay secondary costs for installation and maintenance
  • Who wants the most air cleaning that money can buy

Wall mount purifiers are best for those:

  • With a large budget
  • Living with multiple housemates or a family
  • With specific filter & technology needs
  • With no need for extra features and air purifier placement flexibility

Where should I put my air purifier?

Image of Levoit LV-H132 air purifier in bedroom

Since most people reading this will opt for a standard portable air purifier, I’ll cover the main things to know about those after buying one and getting ready to use it.

Generally speaking, bedrooms and the living room are the best locations to place them.

Definitely place them in rooms that have the most traffic coming in from outdoors or which are periodically exposed to sources of external contaminants like outdoor pollution.

If your pets mainly stay in one room most of the time but do move about (like to your bedroom) you might consider putting one in between rooms.

If you find yourself having allergy symptoms in a particular room, that’s a tremendous clue that allergens are airborne there and you need a purifier in that area.

Air circulation

Don’t place a purifier where air cannot circulate throughout the room well.

For example, don’t place them in areas that are closed-off from airflow or obstruct the flow of air through them. Purifiers work by drawing in dirty air, filtering it, and blowing out the newly freshened air so it’s critical to make sure they have easy access and enough space.

Many models recommend 15″ to 24″ space between them and walls or furniture, for example.

Noise levels & light brightness in other sleeping & study areas

Image showing Levoit Core 300 air purifier in a dark room

If you’re sensitive to light and sound when sleeping or concentrating like I am, definitely consider buying a model that has minimal noise production. Several very good products today have the benefit of allowing you to use them in your bedroom overnight without being disturbed. Otherwise, consider moving it slightly outside of your room.

If you stay in a certain room for sleep or need to concentrate for work or studying, consider placing the device just around the edge of the open doorway or slightly out of the way.

While many sold today have a special low-noise “sleep” mode or other low-speed settings with minimal noise produced while in use it can still be an issue for some of us. This includes me!

I recommend therefore ideally buying a model you know won't produce distracting noise or simply move it into a slightly different area.

Additional air purifier placement tips

Image of child in living room with air purifier
 read the owner’s manual before deciding where to use it!

Don’t forget that reputable brands are well-tested and the manufacturer sometimes recommends the best locations for optimal air cleaning.

Here are a few other things to think about:

  • Don’t put air purifiers in the corner unless otherwise specified as acceptable
  • Try to avoid leaving windows open for very long
  • Make sure your purifier has 1-2 feet clearance (minimal) for best efficiency
  • Keep it a distance of 6-10 feet from the head of your bed
  • Point the output side of the purifier in your direction
  • Make sure the room size coverage of the one you buy is fairly close to, or larger than, your room size

In summary: Do I need an air purifier in every room?

  • No, you don’t. You only need enough to cover the size of the rooms you’ll mainly be staying in or have air quality problems in
  • Estimate your room size and buy products with room coverage close to the size you found
  • Buy quality models and place them in the right locations, positioned properly
  • Most people are fine with a portable model that’s moderately priced. Consider buying one with a germ killer if you are susceptible to sickness or other health problems
  • A good rule of thumb is to start with 1 rated for med. size rooms (living room) and use a smaller model for each bedroom

Levoit Core 300 review editors choice badge product imageFor the average person, I recommend choosing a model that’s a well-rounded combination of price, features, and performance. The new Levoit Core 300 medium room purifier was a great model I recently reviewed.

Find out here why it's one of the best new air purifiers you'll find at Amazon.

Additional reading

As I mentioned earlier, don’t stress if you’re on a budget. I’ve written a helpful guide here with 5 of the top air purifiers under $100.

Be sure to check out my other helpful guides like this one if you have pets or this post if you have a dust mite problem.

The Best Inexpensive Air Purifiers – 5 Great Buys

Best inexpensive air purifiers featured image

If you’re concerned about air purifier costs you may be wondering if you can even afford one. Or maybe you simply want something affordable that actually works well.

Where to begin? In order to help I’ve put together a list of 5 of the best inexpensive air purifiers. Here you’ll find the details & pros and cons to know before buying.

Wondering how air purifiers work and which kind is best suited for you? There’s a buying guide and basic information here to help, too.


A basic air purifier buying guide

There are quite a few products out there today but most fall into 2 major categories:

  1. Ionizers or ozone generators
  2. Filter-based (HEPA) purifiers

1. Ionizers and ozone generators

Ionizer and ozone generator examples image
Left: An O-Ion B-1000 ionizer. Right: An ozone generator. Ionizers are a type of air purifier that use an electrostatic charge to collect airborne particles on plates, removing them from the air. Some also have filters to capture dust & particles. Ozone generators are sold as air purifiers as well but don’t effectively clean air. Ozone also can be irritating to your internal passageways and potentially harmful at higher levels.


As I go into more detail in my post here, ionizers work by generating electrical charges and using plates and/or electrodes to affect air particles. A fan is used to move air through the purifier and as it does, airborne particles get a charge and are attracted to plates of a different charge, trapping them.

Some models have reusable or replaceable filters. Others may include additional features like an activated carbon filter to trap odors or ultraviolet light (UV) germ killer.

One unique property of ionizers is their ability to act as air sanitizers and kill sickness-causing germs.

When compared to filter-based (HEPA) air purifiers, however, they can’t quite compete. I’ll cover that below.

Ozone generators

Diagram showing ozone production and pair particles
Ozone generators work by using a high voltage corona effect to create ozone molecules. Ozone is the funny smell you may remember sensing outdoors after a lightning storm or from an electric train or car sets. It is generated from voltages change oxygen molecules.

The main principle behind it is taking regular oxygen from the air and combining 3 oxygen atoms into an ozone molecule. This molecule has a charge and the atoms 3rd oxygen atom can bond with contaminants in the air.

That’s the idea, at least. However, in practice, ozone generators aren’t very effective. Some do use filters also, but they’re not very efficient and simply aren’t worth the money.

Ozone can be breathed in by humans and pets where it can irritate the respiratory system. It’s especially a bad idea for those suffering from health problems like emphysema.

At higher levels, it’s also potentially harmful to the human body.

Ozone generators are often misleadingly sold as “air purifiers” and while technically that’s true to a lesser degree, they aren’t very efficient as I mentioned. Also, companies often do not include information about the amount of ozone produced, and whether or not they’re safe.

I recommend staying away from ozone generators. They’re a poor use of your money!

2. Filter-based purifiers

How air purifiers reduce dust diagramHEPA filter air purifiers like this GermGuardian AC4825 work by drawing air through filters to capture and remove air contaminants. Clean air blows out and back into the room. They work in a cyclic fashion, continually moving and filtering air. Some also include a type of germ-killing feature in addition to an activated carbon filter to remove odors.

These work based on a simple but effective principle. Fans are used to move air through a very dense filter material called a High-Efficiency Particulate Air (HEPA filter. They’re very effective and are safe as these types of purifiers don’t emit anything into the air you breathe.

Additionally, many have additional features to compliment the HEPA main filter. These are an activated carbon filter to remove odors and chemical vapors and a pre-filter for larger particles.

As they run the air in a room is circulated and continually cleaned. As they work very well for common air quality issues like pet allergies & odors, cigarette smoke, dust, and others they’re very popular.

Most also have selectable fan speeds and can be used on low for more quiet operation at night. You can also find some with additional bonus features like a germ killer to reduce microbes.

How effective are HEPA purifiers?

Diagram showing HEPA filter efficiency

The HEPA name denotes a standard first put into use commercially in the 1950s in the United States. It’s a standardized level of air cleaning efficiency that ensures:

  1. The filter is 99.97% efficient at removing particles
  2. Particle sizes of down to 0.3 uM are captured

For reference, 1 uM (micrometer) is equal to an incredibly small 1/1,000,000 of a meter in size! That’s far smaller than the human eye can see. Truly microscopic in size.

This is important because with purifiers using “true” (genuine) HEPA filters you’re assured of how effective they are.

Additionally, many airborne particulates are very small and you’ll have to have an effective purifier that can remove elements of those sizes if you truly want relief.

Which type of air purifier do I need?

I recommend picking a quality HEPA filter air purifier like those below. Ionizers typically don’t have the proven performance of a good filter based purifier.

They also often have a lower fan speed and can’t move air as quickly.

Filter-based purifiers are also much more suited at trapping dust. Models with a carbon filter can definitely help with odors and other chemical substances in the air.

I own and have personally tested several below and I can vouch for how well they work!

HEPA purifiers have proven, demonstrated effectiveness which is important when buying products like this. You don’t want to spend money on something based on marketing hype, only to find out it’s not helping you.

★ 5 of the best inexpensive air purifiers ★

Our top picks at a glance

sample-table__image★ OUR #1 CHOICE ★GermGuardian AC4825
  • Best seller and overall an excellent value! Easy to use and quiet.
  • 155 sq ft coverage, 100+ CADR lab tested rating
  • True HEPA, carbon filter for odors, UV-C germ killer
Check at Amazon
sample-table__imageULTRA QUIET!Levoit LV-H132
  • Electronic controls and super quiet operation
  • 129 sq ft, true HEPA + carbon filter
  • Touch controls, night light, and memory feature
Check at Amazon
sample-table__imageGermGuardian AC4100
  • Great for dorms and small rooms
  • Same HEPA filter + carbon filter quality as larger models
  • Includes germ-killing feature
Check at Amazon
sample-table__imageHamilton Beach TrueAir
  • HEPA filter can be vacuumed for longer life
  • Works upright or on its side. Great compact, effective air cleaning.
  • Simple 3-speed control. Available in pet version and 2 colors.
Check at Amazon
sample-table__imageUnder $50Holmes HAP9240
  • A great budget choice! Affordable version of a true HEPA filter.
  • Built-in ionizer for additional cleaning. Up to 109 sq. ft. coverage
  • Simple/easy controls. Works on its side or vertically
Check at Amazon

Product reviews and details

1. GermGuardian AC4825 – A winner! Best-selling, effective cleaning with good value.

Best seller product review badge graphic imageHands-down, the GermGuardian AC4825 is one of the all-time best-selling air purifiers today and it’s easy to see why!
You’ll get not only more room coverage for your money but the addition of an ultraviolet (UV) germ killing feature, too.

Take a look at why it’s one of the best well-rounded values today:

  • True HEPA filter
  • UV-C germ killing feature
  • Super-easy filter maintenance
  • Inexpensive replacement filters
  • Separate pre-filter for reduced costs
  • Filter check reminder feature
  • Carrying handle for easy moving
  • Available in white or the AC4900 style, too
  • Lab-tested CADR rating of 100+
  • 155 sq. ft. room coverage

Solid features and performance

The true HEPA filter and odor-absorbing pre-filter work together to keep your dorm room fresh, reduce allergies, and let you breathe & enjoy college the way you deserve.

Nasties such as dust, hair, and more get blocked by the pre-filter which can be replaced separately to keep costs down. The HEPA filter works great to block all kinds of terrible allergens, dust mites, pollen, and even mold spores to freshen the air you breathe and reduce sickness.

Unlike many competitors in its price range, the AC4825 also offers lab-tested performance with a CADR of 100+.

While it may lack the fancier features found in others, it’s one of the easiest to use and very reliable as well. I’m a big fan as I own one myself!

In fact, you can read more in my detailed review of the AC4825 here.

GermGuardian AC4825 top view of controls

The AC4825 features one of the easiest-to-use control setups you’ll find. It’s incredibly easy to use! Set the rotary control to one of the 3 fan speed settings. Use the UV push button to switch the germ killing feature on or off. A power-on indicator LED lights when the purifier is working.

A rotary 3-speed fan control is used to change fan speeds and turn it off. The filter is easy to remove and replace by opening the rear door and simply swapping it out. A filter replacement reminder is included too.

GermGuardian AC4825 side view UV-C feature glowing

The lovely blue trim ring lights up when the UV-C feature’s in use. Don’t worry though – it’s perfectly safe, as the ultraviolet light is trapped inside. It’s a great-looking way to see when the feature is on. I like it!

The ultraviolet light feature (UV-C) works with titanium oxide to break down & destroy illness-causing microbes & germs in the air around you. It’s a nice addition that most competitors don’t offer. 

When switched on, you’ll see a soft, safe glow in the translucent trim around the base of the top that lets you know it’s working to destroy germs.

Overall opinion

At 22 inches in height, it’s not as compact as other models but fits well into corners or other spaces. Replacement filters cost about $15-20 and last about 6 months depending upon use. You’ll also find many 3rd part options offered for those of you on a budget, too!

The GermGuardian line of purifiers is one of the most reputable on the market, and without a doubt the AC4825 is a true “workhorse” that people love, judging by the thousands of great buyer reviews.

I’ve enjoyed mine, too, and I love how hassle-free it is to use. The fan speeds are good, it’s relatively quiet, and works well to solve a whole range of air quality issues.

The true HEPA filter and pre-filter are some of the easiest to replace I’ve ever used! If you’re in the market for a good value but not a wimpy purifier, it’s a great compromise between cost & performance.

While it’s not as quiet as some competitors, it’s still pretty low in noise when running. But that’s one of the few tiny gripes I have since I’ve enjoyed mine so much.

  • Simple 3-speed fan switch is great for nearly everyone
  • Good overall value for performance & room size vs. the Levoit LV-132
  • Great filtering performance
  • Quiet fan operation on low speed setting
  • Germ & microbe-killing UV-C feature not found in many others
  • Filter replacement reminder
  • Soft LED when power is on
  • Nice blue glowing trim when UV-C is on
  • Vertical size is great for corner or areas with more vertical space
  • Good room size coverage (155 square feet)
  • 3-year limited warranty
  • No auto-sensing modes
  • No electronic controls
  • No auto-off feature
  • Cannot wash & reuse filter
  • Design is less stylish and attractive than other competitors in its price range (ex. Levoit LV-H132)
  • Warranty requires paying for return shipment for service

As a happy AC4825 owner, I understand why it’s so popular. It’s well made, works great for cleaning the air, and is frustration-free. Maintenance is cheap, too.

Don’t wait any longer for healthy, fresh air! Head over now to see the thousands of great buyer reviews and current low price at Amazon.

NEW GermGuardian AC4825W white model

Good news! You can now get the AC4825 we happy owners love in white as well.

Want some a bit different looking? Check out its twin, the sleek AC4900CA version here.

2. Levoit LV-H132 – Nice features, performance, and a good choice for small to mid-sized rooms.

Levoit LV-H132 purifier white front view

The LV-H132 provides less room size coverage than competitors like the GermGuardian AC4825 but makes up for it with a lot of great features. It’s a popular model and best seller.

Well suited for small rooms or light duty use in medium-sized rooms, it’s a well-designed model you’ll enjoy using.

It’s also one of the quietest purifiers I’ve ever owned & tested, too!

The 3-stage true HEPA filter is great for eliminating odors, allergens, pet dander, dust mite allergens and so much more.  Odors are no problem, either.

Levoit LV-H132 features image

The Levoit LV-H132 is sophisticated yet still easy to use. Electronic touch controls are provided and beep when operated. After power is switched off the last settings are saved. Upon the next use, the purifier remembers your last settings and restores them automatically.

Of the inexpensive purifiers listed here it has the most features.

The LV-PUR131 uses a 3-stage design similar to others: a fine preliminary filter, an activated carbon filter, and a true HEPA filter that captures and removes dust very effectively.

Sound levels are pleasant and operation is quiet during use. There’s also a lovely night light with 2 brightness settings built in.

The filter replacement reminder indicates when it’s time to check and change the filter if needed.

Levoit LV-H132 filter replacement image example

Filter replacement is a bit different for the LV-H132, but very simple. Turn the unit upside-down, rotate the cover, and then you can pull out and replace the old 3-in-1 filter assembly. Note: unlike some competitors, in most cases, you can’t replace the carbon prefilter separately. It’s something to keep in mind.

Replacement filters run around $30 and are easy to replace by opening the top cover.

  • Lower height than tower purifiers
  • 2-year warranty
  • 3 fan speeds
  • Night light with 2 brightness levels
  • Nice looking, modern design
  • Electronic soft button controls
  • Quiet operation on low level won’t disturb sleep
  • Filter replacement reminder
  • Great build quality & high reliability
  • Easy filter replacement
  • Smaller room coverage than others in its price range (129 sq. ft.)
  • No auto-off timer feature
  • No air quality sensor
  • Electronic controls may not be suitable for some

Of all the air purifiers I’ve owned and tested the LV-H132 had the lowest noise during operation. I was honestly surprised how quite it was!

It’s an excellent choice.

Don’t take my word for it, though. Be sure to check out why it's one of the most popular models and received the Amazon's Choice label.

Levoit LV-H132 black model

UPDATE: A sleek new black version is now available too!

3.  GermGuardian AC4100 3-in-1: Got a small room? Get great performance for less money.

GermGuardian AC4100 angle view
Affordable? Yes. Low on quality? No! I’m an AC4100 owner too (yes, I test many different kinds!) and I can tell you it shares the same quality and performance the GermGuardian purifier family is known for.

It’s a modern looking, well-performing purifier. Measuring only 7.5 x 6.5 x 11″ in size, there’s a true HEPA filter along with a pre-filter/charcoal section to produce fresh, healthy air you’ll enjoy.

The AC4100 is a great choice for small rooms, dorm rooms, offices, and many other places.

Mine works great and it’s a great way to reduce dust if you have problems with it like I do.

GermGuardian AC4100 filter replacement how to image

Filter replacement on the AC4100 is easy! Just open the rear cover, pull out the old filter, and insert the new one. You can also use a vacuum to remove larger particles like dust. As you can see my AC4100 caught more and more dust as I used it!

The UV light (along with titanium dioxide) kills germs to sanitize your air and reduce sickness. Replacement filters cost about $18. A filter installation date wheel is available to mark when you installed a fresh filter.

Image of a GermGuardian AC4100 showing HEPA and activated carbon filters

A 3 simple rotary control adjusts fan speed and turns it off. It’s quiet and generates a pleasing low noise level on the lowest setting. When set to high somewhat similar to white noise is produced.

It’s different from other GermGuardian models in that the UV-C is an on/off switch rather than a push button control. Also, I’m not so happy that there are no indicator lights for the UV-C feature being turned on or the filter replacement.

Those are fairly minor complaints, however. Overall, it’s a great choice for small rooms and I’ve been happy with the ones I’ve owned and tested.

  • Simple 3-speed fan control and on/off UV-C switch
  • UV & titanium dioxide design to kill germs
  • Great filtering ability for its small size
  • High speed setting moves a lot of air for purifying quickly
  • Filter replacement reminder wheel (month installed)
  • Low filter replacement price (about $19)
  • Filter replacement date wheel (marks month installed)
  • Sleek, modern design
  • 1 year warranty is shorter than other models
  • Fan speed on high could be slightly better
  • No filter replacement light
  • No additional colors offered

The AC4100 provides the same quality that earned GermGuardian its reputation as a top air product company. I definitely recommend it for both its great value and low price.

Be sure to check it out! Head over and see the great buyer reviews and low price today at Amazon.

4.  Hamilton Beach TrueAir Ultra Quiet – Inexpensive, compact, and quiet too.

Hamilton Beach True Air purifier black front viewThe Hamilton Beach TrueAir is not just a well-made purifier that’s with that’s inexpensive but one that also helps keep ownership costs down.
The HEPA filter can be vacuumed clean. Under normal use won’t have to replace it as frequently as you would for other brands. It’s a great way to save money.

Hamilton Beach True Air purifier black top viewUsing it is super easy! A simple rotary control lets you select the fan speed desired.

Operation is simple using the 3-speed fan control. It runs quietly during operation unlike some other products out there.

The compact size (8.5 x 13.5″) lets it fit in more spaces. Hamilton Beach rates the room coverage at a nice 140 square feet. Perfect for small to medium sized rooms like offices and bedrooms.

Hamilton Beach TrueAir purifier features image

The Hamilton Beach TrueAir fits neatly into small spaces – especially shelves – as it can be used on its side. Remove the rear cover to vacuum the filter for extended life. It’s a great way to keep costs down.

Another great option it has is the ability to be placed on its side – soft feet keep it steady when rotated.

Unlike the others, there are no additional pre-filter or carbon filter sections. I don’t recommend it, therefore, for odors and smoke for that reason.

(Note: If you have pets, check out the pet version TrueAir Pet Specialized Cleaner).

Color options include both black and white. Note that the different colors may be priced differently from time to time.

  • HEPA filter is effective for average dust and allergen removal
  • Main (HEPA) filter can be vacuumed and reused – low maintenance costs
  • Can be used on its side for even more convenience
  • Quiet operation
  • Nice design
  • Simple 3-speed operation control
  • Limited room size coverage
  • No pre-filter or carbon filter section (odors and cigarette smoke)
  • No power indicator lights or filter replacement reminder
  • No sleep or auto-shut off mode

It’s a nice, affordable option for many people. You’ll be pleased to find out the low price and see the many happy buyer reviews at Amazon.

5.  Holmes HAP9240 HEPA-type desktop purifier – Low on price, high on value.

Holmes HAP9240 air purifier product imageLooking for a competent but lower-priced choice? The Holmes HAP9240 may be exactly what you’ve been looking for. You’ll get a great compromise between performance, filter options, and price.
It’s not the smallest but measures a reasonable 14.8 x 11.4 x 7.2 inches in size.

Featuring a small size that’s perfect for countertops, shelves, and even desks, the Holmes can also be placed vertically on its back. The purifier features built-in rests on the rear to allow it to stand on its end.

For around $50 or so, it’s a good value. Check out the features:

  • Near-HEPA air filter quality for less money (filters 99% of particles)
  • Up to 100 sq. ft. room size coverage
  • 3 cleaning speeds and low noise operation
  • Filter reminder indicator light
  • Optional ionizer feature
  • Can be used in a vertical position
  • Black color option (availability may vary)
  • 3-year limited warranty
  • Washable pre-filter
  • Affordable replacement filters
  • 12 month HEPA filter life

The Holmes desktop air purifier includes a washable filter and HEPA-type filter (left). (Right) Have special air cleaning needs? You’ve got some good options! Pick one of the 3 additional filter options for specialized air cleaning relief.

It uses a HEPA-type filter that’s similar to the filtering qualities of a true HEPA filter. The filter can remove 99% of all particles down to 2 microns in size (as opposed to the 0.3 micron standard of a genuine HEPA filter.)

It’s a budget model but still a good performer for many common air quality problems. The 2-micron particle size rating works well for pet dander, dust, and standard allergens.

I wouldn’t recommend it for cigarette smoke, however, at least not without a carbon filter.

Shown: The Holmes HAP9240 controls are super-simple to understand and use. The filter reminder (left) shows the filter condition and can be reset as needed. Right: The optional ionizer feature is as simple as an on/off switch with light. Center: Choose from Off or 3 fan speeds with low-noise operation.

A built-in ionizer with off/on control is an extra feature that produces a safe level of charged molecules that bond with pollutants in the air. While it’s not the main air cleaning contributor, it’s a nice touch you may enjoy.

Filter check reminder

At power up, the unit will check and show you if it’s time to check and clean or replace the filters using the dual-color light on the control panel. When needed, you can easily reset the check filter light using the reset button provided.

It’s unique in that the pre-stage filter can be removed and washed to be reused. Fan speed is adjustable and while not as quiet as the Levoit and others here, it does offer low noise when at low speed.

Room size coverage and air cleaning performance

It’s recommended for rooms up to 100 square feet in size – just right for dorm rooms! The air cleaning performance is good, too, as it removes allergens, dust, pet dander, and much more from the air very well.

While there are quieter models out there, you’ll pay at least $30-$40, and in my opinion, it’s very quiet on the lower 2 settings. Overall, it’s a nice little budget model I’m sure that’s a great match if you’re on a budget.

Just like experience with it, buyers love it, too, as it’s one of the best-reviewed budget purifiers today.

  • One of the most affordable and biggest sellers on the market
  • 100 sq. ft. room coverage
  • Easy slide control switches & 3 speed settings
  • Pre-stage filter can be cleaned and reused
  • Low replacement filter cost
  • Additional filter options
  • Can be positioned vertically
  • Includes ionizer with on/off control
  • Lower cost version of a true HEPA filter with nearly the same standard of performance
  • Available in black
  • 3-year limited warranty
  • Not as sophisticated as pricier models
  • No germ-killing feature like the GermGuardian products offer
  • Cannot turn off light indicators on panel
  • Styling is more bland

Overall, it’s a very good budget air purifier that’s a great combination of price, performance, and features.

It’s a great little purifier for those on a budget! Find out the current price & availability now at Amazon.

Summary – The best air purifier under $100

The GermGuardian AC4825 is my top recommended for an affordable air purifier below $100 and it’s often on sale at Amazon for below $80. It’s one of the best values as the room coverage is one of the largest in its price class. The quality and performance are both very good as well.

Based on my own testing and as an owner of the AC4825, I recommend it as the best low-cost air purifier under $100. It’s one of the best-selling models in the world, too.

Additional reading

I personally own the GermGuardian AC4825 and was so impressed I wrote a great review here.

If you’d like to find out more about HEPA type vs. true HEPA filters here’s a great post that explains more.

Feel free to post a comment or contact me if you have comments or questions!

HEPA Type VS True HEPA Filters Explained

HEPA type vs true HEPA purifier examples image

Air purifiers are wonderful and can definitely improve your quality of life. Unfortunately, a lot of the ones sold today can be hard to figure out.

You might find some labeled “true” HEPA filters while some others are advertised as “HEPA type.”

To make matters worse, as a new buyer it’s easy to be misled into buying a product that’s misrepresented and pretends to be as good as better-quality products. 

In this post, I’ll explain the difference between HEPA type vs HEPA filters in great detail.


True HEPA and HEPA type air purifiers

HEPA type vs true HEPA purifier examples imageShown: 2 very common air purifiers, which don’t seem very different from the outside. Left: A Holmes HAP242-NUC air purifier which includes a HEPA-type filter and marketed similarly to a true HEPA filter. Right: GermGuardian AC4825 air purifier. It includes a genuine HEPA filter that meets the High-Efficiency Particulate Air (HEPA) standard.

The problem with air purifiers sold today (as pictured above, for example) is that it’s very easy to think they’re all the same. Because of clever marketing, you may think a HEPA-type is just as effective as a true HEPA product.

The problem lies in the details and how filters are rated.

What is a true HEPA filter?

Diagram showing HEPA filter efficiency
High-Efficiency Particulate Air (HEPA) filter describes a type of filter designed to meet efficiency and air purification quality levels set by the United States Department of Energy. These filters are made of a very dense fiber-like material.

To meet the standard a filter must be able to remove 99.97% of airborne particles that enter it down to 0.3 microns in size.

A micron, or micrometer (uM), is 1/1,000,000 of a meter. It’s a common unit of measurement for microscopic elements.

A filter’s efficiency refers to how many particles it can trap and remove from the airflow that passes through it. At 99.97%, for every 10,000 particles flowing into it only about 3 escape.

HEPA filters are very effective at cleaning the air!

The good news is that thanks to the High-Efficiency Particulate Air (HEPA) standard exist it’s much easier to know what you’re getting for your money.

HEPA-type vs. true HEPA explained

HEPA filter efficiency graph

This graph shows how air filters like HEPA filters perform when used in an air purifier.

A HEPA filter’s efficiency actually begins to fall for particles near the size of 0.3uM, which is why they’re rated to “99.97% of particles down to 0.3uM.” Filters actually work even better above that size (as seen in the graph, like 5uM for example).

Following the red line on the graph, you can see that the efficiency (the number of particles it can capture) drops a bit near a certain size range.

The interesting thing to know is that filters actually trap more particles below that size range, but it’s misleading to sell a filter based on that.

Minimum particle size is what matters

The smallest particle size a filter can remove from the air is the most important thing to know. In the case of a genuine (true) HEPA filter, you can be sure that’s 0.3uM (less than 1 millionth of a meter).

“HEPA-type” filters are those that look like true HEPA filters but don’t meet the same requirements. They’re not standardized and can have any range of efficiency and minimum particle size rating.

HEPA-type purifiers are sold to give a buyer the impression they’re getting the same performance when in fact who knows? Unless the specs are specifically made clear, it’s anybody’s guess.

There’s no mandatory requirement for companies selling those to have proof of their product’s performance.

Industry standard ratings

Honeywell HPA160 CADR ratings label image

An example Clean Air Delivery Rate (CADR) label from the Honeywell HPA160 medium-large room air purifier. CADR ratings are lab-verified cleaning efficiency ratings based on measuring how effective an air purifier is for 3 major types of air contaminants.

The industry standard Clean Air Delivery Rate (CADR) is a standardized test carried out by the Association of Home Appliance Manufacturers (AHAM).

The AHAM is an independent (non-government) voluntary industry association that was established to better rate and standardize the ratings of many appliances you buy.

Air purifiers have unique requirements as well so a method of testing their cleaning effectiveness was developed. Using the CADR you can better shop by comparison for those models which include the rating in their specifications.

Understanding CADR ratings

The CADR rating is a cleaning effectiveness rating. It’s a score based on standard lab tests by the AHAM where a purifier is used in a room with a measured amount of air contaminants.

The air purifier is then observed and measured based on how well and fast it can clean the 3 types of contaminants (smoke, dust, and pollen) in a given amount of time.

Air purifiers with a higher airflow rate (larger purifiers with more fan speed) will nearly always rate higher.

That’s expected. Therefore when shopping and reading CADR ratings you should compare purifiers of a similar recommended room size.

(For example, a small room purifier will have a lower CADR rating than a large room one, so comparing them as equals doesn’t make sense).

HEPA-type marketing to watch out for

HEPA type filter marketing gimmicYou might find products advertised as having “99.9% efficiency” or something like that. But the most important thing is what’s the minimum particle size they can filter at that level? What is it? How does it really perform?

Unless it’s specifically made clear, you have no idea how well it’s actually going to work. More than likely it’s not close to the performance of a true HEPA filter and is a bad choice.

In some cases, HEPA-type filters can allow allergens, dust mite particles, and more to escape! That’s because some of the most common airborne particles that give people problems are smaller than they can capture.

HEPA type vs true HEPA visual comparison image

Image showing the filters from the previously shown examples. A HEPA-type filter (Holmes air purifier, left) and a true HEPA filter (GermGuardian, right) look extremely similar. In most cases, you can’t tell the difference just by looking. You’ll need to be very careful and look for specifications that tell you their performance. However, in my opinion, “HEPA-type” filters are best avoided and you should simply get the real thing.

Avoid unknown HEPA-type filters. Don’t waste your money.

Are HEPA type purifiers bad? Are there exceptions?

Holmes HAP242-NUC hepa type descriptionAs I mentioned earlier, it’s generally best to avoid HEPA-type purifiers. But there are exceptions to the rule.

The Holmes desktop air purifier I showed earlier is an example I can use. It’s more of a budget model. However, in this case, Holmes does specify it can trap contaminants down to 2 microns (2uM) in size.

HEPA type filters aren’t “bad” – just a different performance level

While that’s poor in comparison to a real HEPA filter, it’s still ok for some purposes. For example, for larger particles like dust mites, household dust, hair, and so forth it can work just fine.

In that case, you’ll need to be well-educated about what size particles your air problems include. I definitely wouldn’t recommend a HEPA-type filter for smoke, airborne microbes, and other issues.

Smoke particles have been shown to measure well below 1 micron in size, for example.

Honestly, this kind of information isn’t for the average person and leaves too much room for making a bad buying decision in my opinion.

If you’re on a tight budget and your air problems aren’t demanding it’s an option to consider.

However, you can buy a better purifier with a real HEPA and carbon filter for around $50 and up these days.


As they look very similar to each other, you can’t rely on your eyes alone. As I mentioned earlier, because of clever marketing you could be misled into thinking HEPA-type purifiers are just as good as the real thing.

They aren’t.

To recap, here are the most critical points to keep in mind when comparing HEPA type vs true HEPA purifiers:

  • “HEPA-type” filters are not standardized and can’t match the performance of true HEPA purifiers. Often they don’t show the smallest particle size they can trap. This means they’re not a good choice usually but in some cases they’re ok to use.
  • True HEPA purifiers are verified to meet a standard level performance. They’re standardized and must meet the 99.97% efficiency / 0.3uM particle size quality standard.

In my opinion, it’s worth spending a bit more money for a product with better air cleaning ability and that has demonstrated effectiveness.

Additional reading

Speaking of money – got a budget? I’ve got a great list of some of the best air purifiers under $100 here.

One of the best (and that I own) is the super-popular GermGuardian AC4825 I reviewed in great detail here.

Honeywell HPA 300 Review – Check It Out!

Honeywell HPA 300 review featured image

Not unlike the GermGuardian line of air purifier products, Honeywell also produces a large range of popular air purifiers. The HPA family of purifiers includes several models with similar styling and controls.

In my detailed Honeywell HPA 300 review I’ll share with you what you need to know before buying.

There are lots of details I’ve got for you before my final review score and summary so let’s get started!


Getting to know the Honeywell HPA300

Honeywell HPA series family image

Honeywell makes a number of similar products in the HPA series of air purifiers. Shown are 3 very popular models and the suggested room sizes they can clean well.

The HPA300 is actually the larger member of a family of similar products from Honeywell. All of which are reputable models with overall excellent buyer reviews. They’re very popular sellers, too.

The HPA300 and its smaller siblings use 2 types of filters: true HEPA and a separate pre-filter. Both are replaceable. The purifier works by drawing air through a “true” HEPA filter that is very efficient at permanently removing particulates in the air around you.

The front grill draws in air which is filtered and then forced out through the top vent section next to the control panel.

Standing at a large 22.3″ (56.6 cm) tall, it’s a big one.

Unpacking the HPA300 – First impressions


Honeywell HPA300 in box

When picking up my HPA300 I had a good impression right from the start. Much like GermGuardian products I’ve reviewed, I got an impression of quality right away. The box displays a large amount of benefits the purifier provides and also the type of replacement filters you need. I can’t say the same for all products I’ve tried. I was eager to try it out.

How’s the build quality?

HPA300 front image
Build quality is good and it’s a great looking product. The body is made of ABS plastic, but it’s well put-together and I didn’t find any gaps or poor assembly. The finish is a satin black. Both the front and rear are styled similar (note: air is drawn in on the front side only).

After unpacking and removing the top quick start label, I examined the purifier for any noticeable quality control problems. The construction is good, and while like the other purifiers sold today, it’s made of plastic. However, it feels good to the hand and not flimsy. No complaints here.

Looking it over I found no issues with the fit & finish. Gaps between parts were nice and tight and consistent. The purifier doesn’t have any rattling or loose parts, either.

It’s by no means a small product (after all, it is a large/extra-large room purifier!) but I found it easy to remove from the box as well and move around.

New user label

HPA300 quick start label image
One of the things I enjoyed finding was the “new user” label attached to the stop after unpacking. It’s a great way for new buyers (especially those unfamiliar with air purifies or Honeywell products) to get going.

It’s clear and well-written. I’m kind of glad it’s there because otherwise I might have assumed the filters were ready to use and would have turned it on right away. The label instructs you to open the front cover, remove the HEPA filters from their plastic bags, and replace the front grill.

Additionally, it covers basic operation so you can get going without needing the owner’s manual (which I cover below as well).

In my opinion, it’s a great idea. Simply peel it off before using it, as it blocks the fresh air output vent.

Built-in quick reference guide

HPA300 quick reference guide

A handy quick reference guide is built into the body, near the controls. There’s a small tab located at the top of the purifier which when pulled reveals a nice guide to help you.

A nice little surprise was the quick reference guide built-in to the purifier. Located above the touch control panel is a tab sticking out of the body slightly. Pulling it reveals a simple list of helpful instructions as well as the company’s customer support phone number.

It’s an excellent idea and lends a good impression to me about both the design and the company. This is a small but nice feature I haven’t seen in competing products.

Checking out the HPA300’s controls

HPA300 touch control panel image

The Honeywell HPA300 shares a similar control panel with the smaller HPA200 and HPA100 models.

It features touch-sensitive controls that allow you to change cleaning modes, engage the Turbo speed feature, set the auto-off timer, and dim the control illumination.

How do the controls work?

It’s easy to operate in my experience, and I found it a pleasure to use. People who are accustomed to traditional push buttons or rotating switches (as many GermGuardian products use) may find them odd at first. But because the design is so convenient and works so well I can’t find any real faults with it.

The touch controls work smoothly, although on rare occasions I did see it miss my touch or it didn’t register that I was switching cleaning modes. In that case I had to touch it again.

That’s not unheard of for touch-sensitive devices, however, so don’t let it deter you at all. It didn’t happen very often and really wasn’t a concern for me.

Changing cleaning and other modes

3 basic modes of operation are provided:

  1. Germ
  2. General
  3. Allergen

Touching the Power (center) section of the panel rotates the current mode. The modes follow this pattern: Off -> Germ -> General -> Allergen -> Off.

The dimmer also rotates the brightness level of the blue indicator lights used to display current modes. Touching the dimmer control moves though: Full -> Medium -> Low -> Off -> Full and so on.

Similarly, the auto-off timer is initially off and can be rotated through the 3 time options available: Off -> 2 hours -> 4 hours -> 8 hours -> Off.

I found the controls very intuitive to use. I’m pretty confident that nearly anyone would agree. Additionally, you’re off and running after unpacking it in only seconds, because it’s so easy!

I’m not quite sure why Honeywell has named these three modes the way they have, as I noticed when testing it that they’re more similar to low, medium, and high. Perhaps it’s due to the amount of airflow, but unfortunately, the owner’s manual doesn’t go into detail about these modes.


Honeywell HPA300 Specifications
  • Room size rating: 465 sq. ft (large/extra-large room)
  • 3-mode/speed fan control: Germ, General, Allergen
  • Turbo high-speed fan mode for rapid cleaning
  • True HEPA filters (uses 3 Honeywell Type R filters)
  • Smoke CADR rating: 300
  • Dust CADR rating: 320+
  • Pollen CADR rating: 300
  • Touch control panel
  • Quick start guide built into body
  • 2, 4, and 8 hour auto-off timer feature
  • HEPA filter replacement reminder
  • Pre-filter replacement reminder
  • 5-year limited warranty
  • Replacement HEPA filter: HRF-R3 (3 filters)
  • Replacement pre-filter: HRF-AP1
  • Weight: 21 lbs (9.5 kgs)
  • Cord length: 6 ft.
  • Control location: top
  • Size: 20.08 x 10.83 x 22.32″ (51 x 27.5 x 56.7 cm)

CADR ratings

The HPA300 is a larger purifier with a significantly more powerful fan so it’s not surprising to see that its Clean Air Delivery Rate (CADR) is much higher. It’s advertised as being able to cycle and clean the air in a large room in 5 hours and I believe it.

Honeywell HPA300 CADR ratings

The HPA300 has passed an independent 3rd party’s verification test to determine its air cleaning effectiveness. Seen here are the actual ratings.

The Association of Home Appliance Manufacturers (AHAM) testing for CADR ratings provides a way for home appliance manufacturers to demonstrate the effectiveness of their products. Air purifiers in particular are rated according to dust, smoke, and pollen cleaning efficiency, where a higher number is better.

For typical products for small to medium-sized rooms, the CADR from quality air purifier manufacturers tends to be around 100 or so. As you can see here, the HPA300 has an outstanding 300+ CADR for cleaning the most common air quality problems!

That’s fantastic. Most importantly though, you should be spending your money on a product with proven air cleaning performance. The HPA300 meets this & more.

Carrying & moving the purifier

Honeywell HPA300 side carrying handle image

While I’ll admit it looks very big and maybe a little bit intimidating, when actually testing it I found the HPA300 to be fairly easy to move around.

Both sides, near the top, have a place to put your fingers to allow easy moving of the purifier from place to place. It’s a great feature and I didn’t fully appreciate it until I tried it. Really nice!

At 21 lbs in weight (about 9.5 kgs) and 22.3″ (56.7 cm) tall in size, at first glance, you’d think it’s going to be a pain to move to the best spot in your room to use it.

The truth is, it wasn’t at all. I found it pretty easy to move and not at all a problem to deal with.

Air cleaning ability & performance

As it’s rated for up to 465 square feet by the manufacturer, it’s a great choice for extra-large rooms. However, you can definitely use it for large rooms as well. It will simply cycle air and clean them more rapidly than a larger room.

I tested the HPA300 over a series of days and let it run all day while I was out of the house. It’s a great way to come back home and feel the “fresh air” difference that a good air purifier can make.

Additionally, I have a bit of a dust problem so I’m always able to tell what’s working and what isn’t.

Consistently, the HPA300 was very good at removing airborne particles (especially dust, in my case) and left fresh, healthy air for me to come home to.

The Turbo mode is especially helpful if you’re bothered by an air quality issue and need the fastest possible relief.

Other products including the GermGuardian AC5000E don’t provide that special feature.

What kind of filters does it use?

Honeywell HPA300 new filter view image

Right out of the package, the HPA300 comes with all the filter you need, but unlike other brands they’re sealed in plastic bags. Per the instructions (included) you’ll have to open the bags and install the filters. It’s very easy, though. Note that the HPA300 and other similar models use the same filters – just a different quantity.

The Honeywell HPA family of purifiers uses High Efficiency Particulate Air (HEPA) filters as well as an odor-reducing pre-filter for large elements and odors.

HEPA filters are made of very dense material and are very efficient for cleaning air. They can remove 99.97% of nasty elements in your air down to an incredibly small 0.3 microns in size. (A micron, or micrometer, is 1/1,000,000 of a meter in size).

HPA300 HEPA filters open package
Opening one of the Type R HEPA filters before installing it and using the purifier. The included filters are made of a soft but dense material that filters out an incredible amount of unwanted particles in the air. These particles cause allergies, sneezing & sniffling, and much more.

Installing the filters

HPA300 HEPA filters installed new
Installing the new HEPA filters before inserting the pre-filter. Note the easy pull-tabs on the filters. When replacing, this makes removing the dirty filters very easy to do!

Included are 3 Type R true HEPA filters which you’ll need to remove from their plastic bags and insert into the front of the purifier. It’s really easy to do and only took me a few moments.

Honeywell HPA300 pre-filter installation
Installing the odor reducing pre-filter, which is simply placed over the HEPA filters and then covered with the front grill snapped into place.

The odor reducing pre-filter that’s included is basically a large square section of a filter material without a rigid frame attached as some competitors do. It’s simply a matter of placing it in front of the HEPA filters and then attaching the front grill.

Here’s the basic list of air contaminants the HPA300 can remove:

  • Pet dander
  • Pet hair (thanks to the pre-filter)
  • Dust mite allergens
  • Pollen
  • Dust
  • Home construction particles
  • Smoke residue
  • Smoke odors
  • Chemical and organic odors

The pre-filter section is a less dense & thin section covering the active carbon filter. It’s job it so first capture larger items in the air like pet hair, dust, and so on. The active carbon filter traps odors and other chemical substances in the air.

Together, they work well. As I’ve mentioned in my other posts, I have a problem with dust and HEPA purifiers have really helped a lot.

For odors, though, you need to understand that the Honeywell purifier will help, but it isn’t an instantaneous solution. It takes time for it to cycle the air and remove odors…but it definitely helps!

Opening the front cover/grill

Honeywell HPA300 how to open front grill illustration
In order to replace filters or to initially get your purifier set up, you’ll need to remove the front grill.

On the HPA300 this is done by slightly pressing marked points on both the left and right sides as indicated. These are snap-click retainers which hold tabs on the grill in place. The grill has 2 tabs on the bottom which hook into slots before the grill is moved upward and snapped into place.

In doing so, I discovered that it’s very easy to do. However, if you move the purifier and even lightly touch the grill near the top it has a tendency to become loose and the grill needs to be re-seated.

This is a minor complaint, but something to be aware of.

Filter life and costs

Honeywell HPA300 replacement filters imageHoneywell recommend replacing the HEPA filters every 12 months or so and the pre-filter every 3 months.

This is because using the pre-filters both extends the life of the more expensive HEPA filters but also pre-filters have a limited life for absorbing odors and other chemical substances in the air.

This is in contrast to others which average 6 to 8 months before recommended replacement, so that’s actually very good.

Replacing all 3 HEPA filters will cost around $57 dollars or so for a 3-pack made by Honeywell. The pre-filter averages somewhere close to $6, so it’s really a good deal in that case.

While $57 or so may sound like a lot, it’s actually about average as most others cost close to $30 for 6 months or so replacement. Therefore it works out about the same.

Filter replacement reminders

What sets the HPA300 apart from other purifiers is that it features separate replacement reminders for the HEPA and pre-filter elements. It’s a unique feature that few products have.

After a replacement reminder comes on you can check the filter and clear the reminder by pressing the lighted button and hold it for about 2 seconds. It will clear and the reminder will be reset.

Note: you can also replace filters before the reminder occurs and reset the reminder ahead of time, according to the manual. With the unit turned off, press and hold each button separately for 5 seconds. The indicator light will illuminate. Then press and hold that indicator light until it goes off. After this the particular reminder will be reset to its “clean” initial state.

Is it safe? Can the Honeywell HPA300 cause headaches?

As I’ve discovered that many people search for answer to this question, I wanted to cover this topic in my review as well. As I explain more in this post, an air purifier based on filtering the air doesn’t produce any emissions.

The HPA300 simply filters the air – it doesn’t add anything to it or produce harmful or irritating by-products. It will not cause headaches. It is perfectly safe and there are NO health concern to worry about

Using the auto-off timer feature

HPA300 auto off timer feature

The auto-timer shuts off the purifier after 2, 4, or 8 hours have passed. I have to say it’s one of the easiest features like it I’ve ever used! Works great, and the purifier shuts itself off just as expected automatically.

In order to use it, simply touch the clock symbol to rotate through 2, 4, or 8 hour options. Doing so a 3rd time will turn it off again.

I like it – what a great option to have before bedtime. No need to worry about having to get up in the middle of the night to turn it off.

The owner’s manual

Honeywell HPA300 owners manual image

The owner’s manual is only about 8 pages in length for the English section, but it’s very straightforward and clear. Well-written and concise, it covers the most important basic information you need to use and maintain your purifier.

Additionally, one of the best things is that it makes it easy to find the customer service telephone number if you need it!

If you’d like to read more before buying, you can view or download the HPA300 owners manual here.

Noise levels during use

For such a big purifier, noise levels seemed to be very reasonable for Germ, General, and Allergen modes! Germ mode was especially quiet and in fact as low as some of the small or medium room purifiers I’ve tested!

After trying the purifier, it seemed as if those 3 operational modes corresponded to low, medium, and high respectively.

Turbo mode is much louder and of course, isn’t suitable for sleep time. But it’s a great feature to have when you can run it full-speed if the noise won’t be too much for you.

Volume measurements

I used a great little sound level meter to measure volume levels. I tested the volume levels at 1 meter (3.28 ft) from the purifier.

Measurement/ModeVolume (dB)
Off (Room noise)39.3
Germ mode43
General mode49.5
Allergen mode55
Turbo mode61

Turbo is definitely a bit loud and is not suitable for times when you’re close to it. As far as the others are concerned, it’s almost the exact same (relatively low) as smaller purifiers I’ve reviewed before.

I was impressed with that, as originally I thought the 3 main modes would be much worse in terms of noise. It’s a pleasant surprise to use it and not even notice it’s running!

Brightness levels in a dark room

Honeywell HPA300 brightness in a dark room image

I’m very particular about the brightness of my air purifiers during testing, as normally I’m very sensitive to both light and sound when sleeping. The HPA300 does have blue LED backlighting for the controls, however it wasn’t too bright. I was able to sleep without any problem and never actually had to use the dimmer feature.

What’s interesting about this particular model is that despite the fact that I’m normally sensitive to light when I sleep, I never had to use the dimmer feature. Honeywell has built-in a nice little dimmer control (accessed by simply touching the Dimmer button area) for 3 levels of control illumination: Medium, Low, and Off.

However, while doing my “overnight” testing I never had a problem. The HPA300 isn’t very bright at all, unlike the GermGuardian AC4825 for example.

You should have no concerns whatsoever about it keeping you awake at night even in the same room.

Review score & summary

After owning and using the Honeywell HPA300 for some time, I have to say overall I’m impressed! It’s a great purifier and it’s really easy to use.

It does what it’s supposed to and does it well – cleaning the air in large or extra-large rooms. With well-designed features, it’ll be a great choice for your home, too.

Image of HPA300 with Editors Choice badge for review score summaryDefinitely head over to find out for yourself why it's one of the top-rated purifiers sold today at Amazon.

  • Value - 8.7/10
  • Ease of use - 9.7/10
  • Air cleaning ability - 9/10
  • Features - 8.5/10
  • Noise levels - 8.6/10

Good quality, great features, and Turbo speed air cleaning ability make it a smart choice for clean, fresh air in bigger rooms.

Testing the HPA300 was a joy. Although it’s large at 21 lbs and 22″, it’s surprisingly easy to move from one spot to another. Filter replacement is simple and uses readily available/affordable Honeywell modular replacements. Features like Turbo mode and separately removable pre-filters are especially nice. The touch-sensitive controls are a breeze to use and nearly anyone will get accustomed right away. It’s also surprisingly quiet during normal operation. A great buy for your money for larger rooms. It’s a pleasure to own and you’ll love it just as much as I have.


  • High-speed Turbo mode for faster cleaning
  • High CADR rating – great purification efficiency
  • HEPA filters last approx. 12 months
  • Odor-reducing pre-filter is inexpensive ($6 or so)
  • Pre-filter can be replaced separately
  • Carrying handles on both sides
  • 5-year limited warranty
  • Height is about the same as lower-capacity competitors (22″)
  • Touch controls work well and are easy to learn
  • Built-in quick start guide
  • Customer support is good
  • Good owner’s manual
  • Auto-off timer shuts off automatically
  • Low noise levels except for Turbo mode
  • Filter replacement is simple to do
  • Indicator lamp brightness is low for night use
  • Good build quality, fit and finish are nice
  • Filter performance is good, fresh air quicker


  • Auto-off timer only adjustable in 2, 4 or 8 hours
  • Manual doesn’t clarify the 3 main operational modes (Low, med., high?)
  • No auto-sensing feature at this price level
  • Germ-killing feature not available
  • Pre-filter doesn’t feature activated carbon like competitors

Are Air Purifiers Good For Your Health?

Image of child in living room with air purifier

Your home is your safe haven and should be a place that feels great to come home to. But did you know it can harbor some harmful gases and pollutants?

According to the Environmental Protection Agency (EPA), indoor air contains organic chemical pollutants at levels 2 to 5 times higher than those found in outdoor air. Knowing that maybe it’s time to invest in a good air purifier.

But wait – are air purifiers good for your health? Or could they be potentially harmful as well? And which ones are the right kinds to buy?


Answering the basic question – Are air purifiers good for your health?

First off, before going into more detail, here’s a quick answer to your question:

Ultimately, it comes down to this: Yes, the right type of air purifier is good for your health. The wrong type can cause health issues or discomfort.

  • HEPA filter-based air purifiers produce no harmful by-products and are good for your health. They remove harmful and allergy-causing particulates from the air, leaving only fresh air behind.
  • Ozone generators are a poor choice and are potentially harmful. Additionally, they’re very ineffective for air cleaning when compared to HEPA type air purifiers.
  • Ionizers are generally a good way to effectively combat airborne germs that cause illnesses. However, like others, they’re not efficient or effective for the most common air quality problems. Again, a filter-type based purifier is a much better choice.

I’d like to explain exactly why this is – and what kind of purifier you should – or should not – buy.

Some are simply junk and a waste of money. In fact, some can make you cough, feel poorly, and are not good for your health!

Common home air quality problems

(Click image to enlarge)

Indoor pollution is best dealt with by eliminating the pollutants and ventilating your home. Some of us can open windows and let fresh air in for a while, but the problem is that’s a temporary solution – it won’t fix the source of the problem.

While there are too many to list here, some of the most common problems are:

  • Allergens from plants and other materials
  • Pet odors, hair, and pet dander
  • Bad smells from a variety of sources
  • Sneezing, coughing, and sniffling
  • Irritants causing red eyes or scratchy skin
  • Dust mite problems
  • Stale air that doesn’t smell fresh
  • Dust
  • Volatile organic compound (VOC) substances from chemicals

Image note about pet allergies

Unlike temporary solutions, an air purifier can remove air contaminants, pet dander, dust mite irritants, dust, smoke odors, and much more. Some of the most common problems we all suffer from can improve a lot!

Ultimately, the only way to truly deal with an air quality problem is to get rid of the source! If that’s not possible (for example, getting rid of your pets) the solution is to remove the cause as it’s produced.

To do so, however, you’ll want the right kind of product that won’t expose you to potential health symptoms. You’ll also want something that’s effective, too. Otherwise, what’s the point?

Air quality problems air purifiers can help with

Dirty air purifier filter that has collected dust

Shown: My air purifier’s filter after being used only about 2 weeks and capturing LOTS of dust. I was amazed at how much it removed from my room and the air around me!

There are two kinds of indoor pollutants commonly found in homes:

1. Particulate matter: Pollen, dust, debris, hair, pet dander, smoke, molds, bacteria, viruses, and other tiny organisms. Newer homes may contain airborne particles related to new carpet or building materials indoors.

Sometimes matter is brought in from outdoors. A great example is smokers who bring smoker particles inside your home on their clothes & hair, or dirt and plant particles from other places.

2. Gaseous pollutants: The usual household sources, including ingredients in fuels, medicine, perfume, cosmetics, plastics, and other products used for things like cleaning, cooking, or maintenance. Others include smoke or pet odors also.

How does an air purifier work?

How air purifiers reduce dust diagramAn air purifier works by drawing in dirty, contaminated air which is then filtered before it escapes back into the room. A great example is the popular GermGuardian AC4825. An activated carbon filter traps gaseous substances (and larger particles, as it acts as a pre-filter). This particular model also includes a germ-killing feature using ultraviolet (UV) light.

An air purifier is an electromechanical device that cleans indoor air either by removing or destroying the pollutants. Most use a fan to pull dirty air from an enclosed space (your bedroom, kitchen, or living room, for instance) and force the air through a filter or series of filters, trapping unwanted contaminants.

The clean air is then released back into the room. This continues and is a process of continuously cycling air over and over until the room is purified.

Since each group of pollutants has different characteristics, the air purifying system that will work for each of them will also differ.

Some systems work by removing pollutants by one of 3 ways:

  • Mechanical filtration – applicable for particulate matter
  • Electrostatic attraction – applicable for particulate matter
  • Gas absorption – applicable for some gas pollutants

Other systems work by destroying pollutants and work as follows:

  • Ultraviolet (UV) light radiation – applicable for molds, viruses, bacteria, and other biological pollutants
  • Photocatalytic oxidation (PCO) – also uses ultraviolet lamps and is intended for gaseous pollutants
  • Ozone generation – produces ozone molecules (O3) from surrounding oxygen to trap particulates, gases, and biological pollutants

The different types of air purifiers

There’s a number of different types of air purifiers that you should know about, although not all are found in consumer products. Just the same, it’s very helpful to have an overall awareness of what’s out there.

Several of these aren’t something you’ll find when shopping for a product for your home, so don’t stress out about it.

1. HEPA filter purifiers

A HEPA filter is an extremely dense filter made up of many extremely dense fibers packed together. The material traps microscopic particles in the air passing through it. They’re highly effective at cleaning the air and don’t have any undesirable side effects unlike other methods used. Often a HEPA filter is used along with a pre-filter and an activated carbon filter.

The most commonly available type in the consumer market, these are air purifiers that capture particulates using filters. High-Efficiency Particulate Air (HEPA) filters fall under this category and are the standard type you’ll find when shopping.

A HEPA air filter is made of very thin glass fibers randomly woven into a mesh material which is folded to increase its surface area.

Extremely dense in construction, they’re capable of capturing and removing 99.97% of particulate matter as small as 0.3 microns in size (a micron is 1/1,000,000 of a meter).

While there are other types of filters used in some cases (such as HEPA “type”), they’re not as effective if they don’t meet the government specifications the HEPA filter standard requires.

Normally they’re used along with 1 or 2 more filter sections such as a mesh prefilter (for trapping dust, hair, and larger elements) and an odor and gas-absorbing section.

2. Electronic air cleaners

Orion B-1000 air purifier with filter shown

Electronic air cleaners like this B-1000 ionizer shown here work by generating charged particles. These particles then can cling to particulates in the air as well as neutralize germs, too. A well-designed unit collects the foreign matter in a filter (shown) or on a plate.

Electronic air cleaners draw air into an ionization section where particulates are electrically charged.

Electrostatic air precipitators and air ionizers are two examples of electronic air cleaners. In the case of precipitators, these charged particles are attracted to plates with an opposite electrical charge as they pass through in the air, removing them from the air.

Ionizers create the charged particles which bond to air particles and then metal collection plates or a filter inside the device.

Unlike air filters that are tested using HEPA standards, there’s no way to gauge the effectiveness of electronic air cleaners. They also produce small amounts of ozone – a three-oxygen molecule which can irritate the lungs – as a by-product.

Why ionizers are a bad choice

Ionizers have been proven to rid the air effectively of sickness-causing microbes, so they can offer a great benefit if designed correctly.

Despite this, they can’t purify the air nearly as effectively as filter-based purifiers can. If you’re considering buying an ionizer purifier, it’s important to be aware that most aren’t really worth the money.

3. Ozone generators

Image of ozone generatorOzone generators produce heavy amounts of ozone molecules by using a high voltage device to split oxygen molecules. The oxygen atoms recombine as ozone (03). These can bond to particles in the air and may give the impression of fresh air being generated. They don’t permanently trap particulates in the air as filter-based types do.

Ozone generators are a type of air cleaner designed to oxidize biological contaminants, odors, gaseous pollutants, allergens, and particulates. Ozone has to be used in high concentrations to be effective.

At first glance, it can seem like ozone is a great way to eliminate pollutants in the air without even needing a filter or even fans in some cases. Many sold today on the market are listed with big claims and fancy technical terms but in truth are very poor performers.

Unfortunately, ozone can exacerbate symptoms in asthma sufferers, cause shortness of breath and throat irritation, and even lower the body’s ability to ward off respiratory infections.

In fact, the EPA recognizes ozone as a lung irritant and products often have ratings to let you know how much they produce.

Sales gimmicks and your money

As I mentioned earlier, ozone generators are often sold with misleading advertisements to make consumers think they’re effective and will freshen the air well. The truth is, they really don’t!

Ozone itself can attach to airborne particles and trap it, but the problem is that it takes an excessive amount of ozone for them to be anywhere near effective. Therefore, they aren’t recommended for enclosed rooms and especially not for people with asthma or other respiratory problems.

Diagram showing ozone production and pair particles
Some air purifiers have an ionizer or ozone generator as an extra option. These types are less likely to produce unsafe levels as they’re a secondary feature and aren’t a health threat in most cases.

The most prevalent problem with ozone generators is that they can’t purify the air efficiently as a filter-based product can.

4. Ultraviolet (UV) germicidal irradiation air cleaners

Diagram showing how UV light kills germs & DNA

Ultraviolet light damages the DNA of airborne germs and microbes at the molecular level, rendering them harmless.

UV-based cleaners are intended for the destruction of molds, viruses, and bacteria either airborne or populating along the HVAC ductwork. These serve primarily to cleanse the air of germs and don’t remove particles and other foreign matter from the air as filters do.

However, many of these biological pollutants produce higher levels of UV radiation than is provided by most UVGI cleaners designed for home use. Dead or inactivate microorganisms can still trigger allergies and respiratory problems.

Also, there’s no way to tell how effective UV cleaners are since there aren’t any standards to test them or compare them when buying.

In air purifiers available for home use, the UV feature serves as a side benefit for reducing airborne germs and microbes.

In summary – Are air purifiers good for your health?

Ultimately, it comes down to this: Yes, the right type of air purifier is good for your health. The wrong type can cause health issues.

  • Filter-based air purifiers produce no by-harmful by-products and are good for your health. They remove harmful and allergy-causing particulates from the air, leaving only fresh air behind.
  • Ozone generators are a poor choice and are potentially harmful. Additionally, they’re not nearly as effective as filter-based products.
  • Ionizers are generally a good way to effectively combat airborne germs that cause illnesses. However, like others, they’re not good for efficient and thorough air cleaning. Again, a filter-type based purifier beats them in that area.

Ideally, for the best health buy a true HEPA filter-based purifier. These will reduce airborne allergens and particulates that cause problems. A model with an ionizer or UV germ-killing feature is an ideal choice and won’t cause health issues.

These won’t produce excessive amounts of ozone and the UV light won’t be a health hazard for your either.

It’s very important to buy a reputable, proven brand that isn’t misleading you with hype or false claims. Many sold (especially from China) are simply ozone generators that are bad for you and simply don’t work well!

Don’t worry, though! You can buy a great HEPA filter purifier for under $100. You can find some great choices you can afford in my detailed post here.

Ionic Air Purifiers Vs. HEPA Purifiers – What’s The Difference?

Ionic air purifier vs HEPA featured image

Are you trying to understand the difference between an ionic air purifier vs. a HEPA purifier? I’ll be honest and admit a long time ago I was confused too. One reason is because of misleading product descriptions I had to research and verify.

It seems like there are so many products sold today as air purifiers. And many are falsely described – which makes it even more confusing! My main goal is to answer your questions about both the differences between an ionizer purifier vs. HEPA purifier.

Before spending any money it’s well worth taking a few minutes to find out more what you really need. I want you to get the best for your money and the best product for your needs.


Infographic – Ionic air purifier vs. HEPA

Ionic air purifier vs. HEPA infographic diagram/image

What does an ionic purifier do?

ionizer purifier examples

Examples of two popular and commonly sold ionic (ionizer) air purifiers. Left: O-ion B-1000 purifier and (right) the No products found. Both use charged plates to attract particles from the air which collect in a filter or on plates for later removal. Both also use a fan to move air through the ionizer section of the purifier. Both also have a UV-C light feature to kill germs.

Air ionizers work by processing air moved by a fan using electrically charged plates to charge air molecules. These ions – or charged air molecules – are attracted to plates or electrodes very much like how static electricity works.

How ionizers work

Ionic air purifier how it works diagramShown: one of many ionizer designs. In this example (of a design used by better ionizer air purifiers) air is moved by a fan through the first filter. Following this, particles in the air are charged (ionized) and then attracted to metal plates of an opposite charge where they’re captured. A final filter removes some more particles in the air. Note that not all ionizer air purifiers have filters.

Ionizers come in different designs. Not all work the same.

For example, better models have a fan to circulate air in a room and others don’t. In order to purify the air in a room, a product absolutely must actually move the air through it and process it to remove contaminants.

Generally speaking, however, ionic air purifiers use a fan to move air through a series of electrodes and plates. The first plates use an electrical charge to ionize (change the electrical charge of) the airborne particles.

The 2nd stage features other electrodes or plates which have an opposite charge. When the newly charged particles move close to them, they’re attracted to them and bond to them, removing them from the air.

It’s very much like static electricity. For example, think about how pieces of paper, hair, or styrofoam are attracted to your body and clothes when you build up a charge on your carpet.

These contaminants collect on plates or similar type of filter where they’re cleaned off later. Some models feature standard filters as well.

Sometimes ionizers are a feature built into HEPA type purifiers as an added benefit.

One major strength of an ionizer is its ability to destroy airborne illnesses by killing microbes in the air.

Ionizers vs ozone generators

Image of ozone generatorUnlike ionizers, ozone generators produce a lot of ozone molecules in the air and don’t internally collect contaminant particles. The idea is for ozone to bond with airborne particulates which then fall from the air. They’re not very effective at safe ozone levels and at levels where they are effective, the ozone is potentially harmful to humans.

It’s important to cover this topic as unfortunately ionizers are often confused with ozone generators. Companies selling ozone-generating “purifiers” often mislabel them and it simply adds to the confusion.

By nature, ionizers do generate a very small amount of ozone but don’t generally do so at an unsafe or harmful level.

Ozone generators are different from ionizers in that they primarily generate ozone (O3 molecules) by using a high-voltage corona effect to split oxygen molecules in the air which form with other oxygen atoms.

They usually use a fan to blow these molecules into the room, but a lot of them don’t contain internal filters for trapping contaminants. Instead, particles fall to the floor around it.

Why ozone generators are a poor choice

I recommend you avoid these and decide between an ionic purifier and a filter-based (HEPA) purifier. Ozone generators aren’t effective and even if not harmful can irritate your respiratory system.

They’re also a bad choice for people with health issues related to emphysema and other conditions.

What does a HEPA purifier do?

Image of Levoit LV-H132 air purifier in bedroom

Commonly sold HEPA filter air purifiers like the Levoit LV-H132 are placed in rooms where air quality issues are present. Some of the most common locations are bedrooms and living rooms. They circulate air using fans, moving the air through different filters that trap unwanted elements. You’ll need to replace the filters with new ones once they’re saturated with contaminants.

HEPA air purifiers are designed to circulate air in the room and remove contaminants, dust, allergens, and more by trapping them in filters. Unlike ionic purifiers, HEPA purifiers always use a fan – it’s not possible for a product to work without one. Also, they generally do not affect air molecules using any type of electrostatic charge as ionizers do.

(Note that there are some exceptions which I’ll cover later)

A High-Efficiency Particulate Air (HEPA) filter refers to a particular type of filter designed to meet certain efficiency and air purification quality levels. These filters are made of a very dense fiber-like material.

The HEPA name describes a standard that mandates a filter can remove airborne particles down to 0.3 microns in size. A micron, or micrometer, is 1/1,000,000 of a meter. The efficiency of this type of filter is 99.97%, meaning that for every 10,000 particles flowing into it only about 3 escape.

They’re very effective at cleaning air.

How HEPA purifiers work

How air purifiers reduce dust diagram

HEPA filter-based purifiers don’t produce anything in the air or cause any type of electrostatic charge, unlike ionizers. They work off of a simple principle: using a fan or fans to circulate the air in a room and move it through filters. These filters trap both larger and microscopic particles, odors, chemical vapors, and many common household irritants.

HEPA filter purifiers are pretty simple in principle although many variations with more features exist.

They all share a similar design: A fan (or fans) is used to draw in air and force it through filters that trap odors and contaminants to blow out fresh air. They continue to do so in a circulation pattern to clean the air in a home or room within several hours.

Unlike ionizers, they depend on the fast movement of air and a filter. While ionizers use an electrostatic charge to remove particulates in the air you breathe, these rely on mechanical means.

In other words, instead of “attracting” particles in the air, they block and trap them in filters.

Some add more features

It’s worth noting that some filter-based purifiers may include unique features like an ultraviolet light (UV) germ killing option. Some may even include an ionizer feature themselves! However they still heavily rely primarily on filters to work effectively.

For convenience, some also offer more advanced features like an air quality sensor or auto-off timer. Others today allow smartphone control features.

Filters used in HEPA purifiers

It’s actually rare that a modern air purifier like this has only a HEPA filter. Today, most products include some variation of a “3-in-1” design:

  1. Pre-filter section
  2. Activated carbon (charcoal) section
  3. HEPA filter

The pre-filter is normally attached to an activated carbon filter section. It’s a thin material that traps larger matter like hair and dust. The activated carbon filter is the section that absorbs vapors and odors.

Ionic air purifier vs HEPA purifier comparison

By now you should understand more about how ionic and HEPA purifiers work. You really shouldn’t spend money until considering the pros and cons of each.

In order to make it a bit simpler, I’ve put together a comparison table that highlights the differences between the two along with a few notes. (Some characteristics are often different on a brand & product basis and are not true in all cases).

Ionic vs HEPA comparison table

Air cleaning process Charges air particles which are collected on plates or filter. Fan moves air through the purifier. Cleans air by circulating air. Air is forced through HEPA/pre-/carbon filters, trapping particulates
Ozone production Very small (< 0.05ppm typical) None
Germ killing ability Low to good, depending on product None to fair (some products feature germ killing ability)
Air flow rate Low-fair (fan speed often not selectable) Good-high (adjustable fan speed)
Dust cleaning Poor Good
Cigarette smoke cleaning Fair-good (particles to 0.01uM in some cases) Good (limited to particle size to 0.3uM and above)
Odor reduction Poor/moderate Good (models with carbon filter)
Pet dander cleaning Fair-good Good
Pet hair cleaning Poor Good
Allergy relief Fair Good
Filter maintenance Clean plates/wash filter (reusable) Replace complete or separate filters, depending on model (ave. 6-8 months life)
Average cost $50-$65+ $50-$100+

Which one should you choose?

Confused man in suit
Ionic purifiers do have a distinct advantage over HEPA type purifiers: their ability to sanitize the air and greatly reduce airborne germs which cause illnesses. Filter-type purifiers don’t normally have this ability although some like GermGuardian products do have a feature that uses UV-C technology to do so.

Some ionizers like the O-Ion B-1000 in the image above also have this feature, too.

However, when comparing the pros and cons of each, I recommend a quality HEPA-type purifier. They offer a higher rate of airflow for better clean air delivery, they’re good for dust and hair problems, and models with a carbon filter can absorb odors and chemicals in the air.

Another reason is that ionizers are not held to the same standards of performance and demonstrated air cleaning that filter models are.

For example, the Clean Air Delivery Rate (CADR) is laboratory tested and proven testing. It’s a standardized way of demonstrating an air purifier’s cleaning effectiveness. You won’t see that on ionic air purifiers.

When are ionizers a good idea or helpful?

Ionizers are good for light-duty cleaning like needing to freshen a room as well as other less demanding applications.

For pet dander, allergies, bad smoke problems, and others HEPA purifiers are the way to go. Additionally, the faster fan speeds mean air cleaning is more rapid and you have more control over it.

The major downside of HEPA purifiers is needing to buy replacement filters, which on average is about 6-8 months depending on the model. (Note that in some cases carbon filter can be replaced separately, extending the use of the main HEPA filter section).

Hybrid models

Holmes HAP116Z-U

Some models use both filters and an ionizer to clean the air. Note that purification effectiveness can vary greatly, so it’s very important to always buy a proven, effective product.

To (unfortunately!) make things more complicated, there are some hybrid models on the market which feature both a filter and a built-in ionizer section as an extra feature.

Primarily, however, you should always shop for a purifier on the basis of proven performance, great reviews, and cleaning ability for your room size. Don’t let marketing tactics mislead you into spending money on something that’s less effective.

Summary – Ionic vs. HEPA air purifiers

In summary here’s what we’ve learned:

  • Ionic (ionizer) air purifiers work by moving air. Airborne particles are charged and attracted to plates where they collect on plates or a filter. Ionizers are more effective at sanitizing air.
  • High-Efficiency Air Particulate (HEPA) purifiers move air through filters to trap particles, odors, and more. They don’t introduce anything into the air itself.
  • Ozone generators may be misleadingly sold as “ionizers’ but aren’t a good use of money, and aren’t effective. Ozone can irritate internal tissues. At high levels, ozone molecules can become harmful.

Be sure to do your reading before spending money!

One of the best HEPA purifiers sold today is the GermGuardian AC4825. It’s an effective purifier with good performance – and I own one! You can read my detailed review here.

If you’d like to see a good ionizer that’s moderately priced, check out the O-Ion B-1000 here as well.

Honeywell HPA 160 Review – A Great Medium/Large Room Purifier

Honeywell HPA 160 review image

Honeywell produces some of the best air purifiers today. As I’ve owned and review several others, I was intrigued by the HPA160 and wanted to see how it stacks up against the competition.

In my Honeywell HPA 160 review I’ll go into detail and tell you if it’s a good choice for your money (Hint: I really like it!)

Competing with popular and high-quality brands like Levoit and GermGuardian, the HPA 160 definitely has to be top-notch in order to succeed.

Read on if you’d like to find out all the details!


Getting to know the Honeywell HPA160

Honeywell HPA060 vs HPA160 vs HPA200 comparison imageThe HPA 160 is part of Honeywell’s HPA series of air purifiers. They all share similar styling and us modular HEPA filters, meaning they use 1 or more of the same filters sold by Honeywell for similar purifiers. They’re also very similar in how they function control-wise, too.

The HPA160 is a “tower” purifier, meaning it has a bit of a lean design and stands tall. At almost 26″ (10 cm) in height, it’s a good looking unit and has a sleek, stylish design with contrasting silver controls within a glossy black panel.

It’s actually one of the many models produced by Honeywell in the HPA series of air purifiers. As the “big brother” to the HPA060 which is designed for small rooms, the HPA160 is designed for medium to large rooms about 170 square feet in size.

Of course, there’s absolutely no reason you can’t use it in smaller rooms, and it will clean the air in them even faster.

The HPA160 and other similar models in the product line use a true HEPA filter and a separate pre-filter to clean the air and permanently remove particulates that cause allergies, odors, and much, much more.

The HEPA filter difference

It works by using a “true” HEPA filter that’s highly efficient at removing nasty particulates in the air. Some of these are incredibly small – microscopic in size! The pre-filter complements the main HEPA filter by capturing odors and larger elements like hair and dust.

The HPA160 is very similar in design to the competing GermGuardian AC4825 in that it draws in dirty air from the rear using fans. This air is drawn through the filters then blown out of the front, producing clean, fresh air into the room.

It works by continuously cycling this process in order to purify a room’s air in a few hours.

The HPA160 uses simple controls (one of which is a touch control – I’ll go into more detail later) and has a black satin plastic body. The controls are accentuated by a nice satin silver trim around the gloss black and satin silver control section.

Unboxing the HPA160 and first impressions


Honeywell HPA 160 unboxing packaging image
Unfortunately because of some distractions I had to delay opening my HPA160 after picking up. Finally, I got my hands on it! Upon opening it I found the same level of quality I experienced with the larger HPA200, it’s bigger brother for large rooms. The packaging was both of good quality and appeared to be environment-friendly as it was made from recycled cardboard material.

How’s the build quality?

Honeywell HPA 160 close up image
This is a well-made and solid air purifier. The body is made of an ABS plastic with a satin (low-gloss) finish. The fit & finish were good and panels lined up nicely and with no noticeable problems. The assembly was tight and well put-together. It looks good and feels good to the touch!

As I always like to do I opened up the box to get an initial impression of the level of quality I’m getting. The Honeywell packaging was good and I was happy with how it appeared. The box is very nice also, as it not only features the benefits of the purifier but also clearly indicates which filters you need to buy for replacement.

As I have experience with both the Honeywell HPA200 and the HPA300 models, I wanted to see if it met the same expectations those set for me. It did! The HPA160 is well-made and looks great, I have to say.

You can easily tell that someone did their homework when designing this model, as it looks very well designed and isn’t a copycat of other similar products on the market.

Although it’s a bit tall at around 26″ (about 10 cm) in height and weighs about 10 lbs (4.5 kgs) it’s actually pretty easy to move around.

There’s a handy carrying handle built into the rear which makes it easy to move. There are rubber pads on the base to keep it from scratching your floor as well.

Getting started

Honeywell HPA160 getting started image

After removing it and unwrapping the plastic, you’ll find a notice label on top of the purifier, near the controls. You’ll have to remove the filters from their bags and re-insert them into it.

While it can seem like a bit of an annoyance (especially considering that other brands don’t do this) I can appreciate that Honeywell keeps filters 100% fresh and undisturbed in these bags.

Essentially, getting first set up is very easy:

  1. Remove the rear cover (see below, where I go into more detail)
  2. Remove the pre-filter, in the rear cover, from its holding tabs
  3. Remove it from its plastic bag and re-insert it into the tabs
  4. Remove the 2 HEPA filters and remove them from their bags
  5. Hooking the filters on the bottom slots in the body, insert them into the snap tab
  6. Re-install the rear cover

It only took me a minute or two to do this, and once you’ve done it for the first time it’s not really an issue any more.

I did notice that the bottom filter was a bit harder to get into the purifier for some reason. Perhaps it was because this was my first time doing so, but it didn’t go in as quickly as I had hoped. But, it still wasn’t a real issue for me and I was on my way fairly quickly.

Built-in quick reference guide

HPA160 quick start guide image
Just above the rear cover’s release tab there’s a clear plastic loop. Pulling it up reveals a great little quick start guide. It’s a nice touch and very handy – you can’t lose it! It also features Honeywell’s customer support phone number. I really like this extra feature.

When getting started with your purifier for the first time, you might appreciate a special little added bonus this model has. There’s a quick-start guide on a printed plastic sheet that is built-into the body. It’s located on the rear just above the cover’s release tab.

Pulling the small clear plastic loop reveals some basic instructions for using the purifier as well as the company’s customer service line and website should you have questions.

I think it’s great and it’s reflective of the Honeywell quality. Several other models in the HPA family feature this a swell. For people who lose manuals easily or new users, it’s a great way to never have to worry about instructions.

Checking out the HPA160’s controls

Honeywell HPA160 controls
The HPA160 is sort of unique in that it features a touch control for the operational mode and fan speed (like the larger HPA200 but push buttons for other features. It’s a bit of a cross between the two types. It looks great and is easy to operate. I like how it looks: satin silver finish on the trim, brushed metal buttons, and a gloss black inset between them. Very classy.

The HPA160 borrows one feature from the larger HPA200 & HPA300 models: the fan mode is a touch control. However, unlike them, the Turbo and auto-off controls are not activated and use push buttons.

Two filter replacement reminders are provided, which is rather unique for an air purifier in this price range. It’s a great feature considering you don’t have to replace both filters at the same time as that’s more expensive.

Rather you can replace the pre-filter separately and later the HEPA filters as well.

How do the controls work?

By lightly touching the main fan speed button the purifier rotates through one of 3 operational modes.

Pushing the button with the clock symbol turns on the 2 hr auto-off timer. Pushing it again moves the selection to the 4 hr option, and so on.

When the Turbo button is pushed the purifier operates at maximum speed. Touching it again restores the previous fan mode in use.

Changing cleaning and other modes

3 basic modes of operation are provided:

  1. Germ
  2. General
  3. Allergen

These modes are really easy to control and you simply push the button again to rotate through the various settings.

Cleaning mode: Off -> Germ -> General -> Allergen -> Off.

Likewise, the auto-off timer is initially off and can be rotated through the 3 time options available: Off -> 2 hours -> 4 hours -> 8 hours -> Off.

In my opinion, the controls are incredibly easy to use and great for first-time owners.

I’m a bit confused, however, why Honeywell has named the 3 fan (cleaning) modes Germ, General, and Allergen. After using it, it seems as if they’re just low, medium, and high fan speed modes. Unfortunately the manual doesn’t differentiate these in detail.


Honeywell HPA160 Specifications
  • Room size rating: 170 sq. ft (med.-large room)
  • 3-mode/speed fan control: Germ, General, Allergen
  • Turbo high-speed fan mode for rapid cleaning
  • True HEPA filters (uses 2 Honeywell Type H filters)
  • Smoke CADR rating: 110
  • Dust CADR rating: 120
  • Pollen CADR rating: 130
  • Touch control panel for fan mode
  • Quick start guide built into body
  • 2, 4, and 8 hour auto-off timer feature
  • HEPA filter replacement reminder
  • Pre-filter replacement reminder
  • 5-year limited warranty
  • Replacement HEPA filter: HRF-H2 (2 filters)
  • Replacement pre-filter: HRF-B2
  • Weight: 10.1 lbs (4.58 kgs)
  • Cord length: 6 ft.
  • Control location: top
  • Size: 8.11 x 11.08 x 25.59″ (20.6 x 28.1 x 65 cm)

CADR ratings

The HPA160 has pretty good fan speed which gives it a good Clean Air Delivery Rate (CADR) rating. The CADR is a documented test that determines how quickly an air purifier can clean the air in a room – the higher the score, the better.

Honeywell HPA160 CADR ratings label image
The HPA160’s AHAM ratings label. Unlike some of the other products sold today, Honeywell has had an industry standard performance evaluation performed. It’s a great way to know you’re getting an effective purifier with proven results.

The Association of Home Appliance Manufacturers (AHAM) provides home air quality testing for air purifier manufacturers. Air purifiers in particular are rated according to dust, smoke, and pollen cleaning efficiency. The higher the number the better.

It’s basically a rating you can use to evaluate 2 similar models when shopping. The rating is also based on the amount of air cleaning due to the rate at which a purifier can move air. Naturally, bigger air purifiers therefore have high ratings.

The HPA160 of course cannot match the larger and more expensive HPA200 and HPA300 models with larger fans, but it can definitely provide efficient air cleaning.

Carrying & moving the purifier

Honeywell HPA160 side view handle

The HPA160 has a built-in carrying handle on the rear near the top.It’s easy to move it around as needed by placing your fingers inside with 2 hands. Very handy!

Although it’s rather tall at almost 26″ in height it’s actually easy to move to different locations in your room. I measured the weight at about 10 lbs (4.5 kg). I didn’t have any issues or find it clumsy to move about.

Honeywell has added a nice feature to make it portable – there’s a carry handle area on the top rear. That’s a nice touch which is also shared by some of the GermGuardian products too.

Air cleaning ability & performance

I’m especially enthusiastic about home air quality and wanted to see how well the HPA160 performed.

I’ve had problems with dust in my home for a considerable time. After seeing how much relief the GermGuardian AC4825 gave I wanted to compare this one as well The end result? It works very well!

The Turbo mode is a special feature unique to the Honeywell product line. It maximizes the fan speed in order to more quickly purify your room’s air when you don’t mind the additional noise volume. After a using it for some time I began to appreciate it more and more.

While there are other products with somewhat similar cleaning ability like the GermGuardian AC5000E the others don’t have a Turbo high-speed feature.

What kind of filters does it use?

Honeywell HPA160 filter images
The HPA160 uses 2 standardized Type H Honeywell filters (white) also used by some other models as well. The Type B pre-filter (black) is separate and is held in the rear cover as shown.

The High Efficiency Particulate Air (HEPA) filters are used in conjunction with a pre-filter (fitted into the rear cover) which catches larger elements like hair and larger dust. It can additionally trap odors over time as well.

HEPA filters are made of very dense material and are very efficient for cleaning air. They can remove 99.97% of nasty elements in your air down to an incredibly small 0.3 microns in size. (A micron, or micrometer, is 1/1,000,000 of a meter in size).

The design allows Honeywell to share a standard size filter in different quantities for use by several different models in the product line. The HEPA filters sell for close to $20 for a 2-pack and the pre-filters for about $9 for a 2-pack as well.

As an example, the HPA060 uses 1 Type H HEPA filter. The instructions are very clear and it makes things easier and less confusing when it comes time to buy a replacement filter.

Installing the filters

Honeywell HPA160 filters image
After removing the purifier from the packaging, you’ll need to open the rear cover, remove the filters from their bags, and re-install them. It’s not hard to do, although for some reason the bottom one was a bit trickier to insert my first time.

The purifier is shipped with 2 Type H true HEPA filters which you’ll need to remove from their plastic bags and insert into their openings. Similarly, the pre-filter must be removed from the plastic bag and inserted into the filter cover/grill as shown earlier.

The HEPA filters weren’t hard to install, with the exception of the bottom one a small bit. They’re inserted bottom-first at an angle into a small slot on each side. They’re then angled upward and click into place in a retaining tab at the top.

Overall I found it easy to do, however, the bottom one was a bit resistant to going in on my first try.

The odor reducing pre-filter that’s included is basically a rectangular section of filter material. It’s held in by tabs on the cover.

Here’s a list of some of the most common elements the HPA160 can remove:

  • Pet dander
  • Pet hair (thanks to the pre-filter)
  • Dust mite allergens
  • Pollen
  • Dust
  • Home construction particles
  • Smoke residue
  • Smoke odors
  • Chemical and organic odors

The pre-filter

This is a less dense, thin section that traps larger particles like hair, fuzz, and so forth before they reach the HEPA filters. It’s also treated in order to reduce odors and trap substances like that in the air.

When combined, these 2 types of filters form an effective way to clean the air. The pre-filter also reduces the need to replace the filters – which Honeywell recommends is every 12 months. 3-6 months for the pre-filter, or as needed if heavy use has occurred.

In the case of odors you need to understand that the Honeywell purifier will help, but it isn’t an instantaneous solution. It takes time for it to cycle the air and remove odors. It’s great to have, however!

Opening the rear cover

Honeywell HPA160 open cover diagram
Opening the rear cover is simple. Just 1) push down on the release tab with your thumb and 2) swing the cover down, then pull it out. There are 2 tabs at the bottom which fit into slots which are used when reinstalling it.

Do these in reverse order after replacing filters. The release tab will snap at the top indicating it’s locked into place.

It’s very simple and I don’t have any complaints. It’s also how the rival GermGuardian AC5000E is designed as well.

Filter life and costs

Honeywell HPA160 replacement filters
Honeywell recommends replacing the HEPA filters every 12 months or so and the pre-filter every 3 months.

This is because using the pre-filters both extends the life of the more expensive HEPA filters but also pre-filters have a limited life for absorbing odors and other chemical substances in the air.

This is in contrast to others which average 6 to 8 months before recommended replacement, so that’s actually very good.

Replacing both HEPA filters will cost around $29 dollars or so for a 2-pack made by Honeywell. The pre-filter averages somewhere close to $6, so it’s really a good deal in that case.

While $29 or so may sound like a bit of money, it’s actually not bad at all as many other products cost close to $30 for each 6 or 8 month replacement period.

Filter replacement reminders

Honeywell HPA160 filter reminders image
The replacement reminders are illuminated based on the amount of time the purifier has been used for. They can be reset as needed. It’s unique in that they’re separate rather than there only being one (as many competitors do).

What sets the HP160 apart from other purifiers is that it features separate replacement reminders for the HEPA and pre-filter elements. Honeywell’s design is different and many, if not most competitors don’t feature this.

When one or both are illuminated you may check the filters. The reminders are cleared by pressing a button and holding it for about 2 seconds. The light will turn off clear and the reminder will be reset.

Note: Of course, you can also replace filters before the reminder occurs according to the manual. Purifier switched off, press and hold each button separately for 5 seconds. The indicator lights will illuminate. Then again press and hold that indicator light until it goes off. After doing so a reminder is returned to its reset state.

Is it safe? Does this purifier produce ozone? What about headaches?

There’s no ozone produced.

The subject of headaches and air purifiers is actually a highly researched question on the internet. As I explain more in this post, an air purifier that only filters the air doesn’t produce any emissions.

The most important thing to know is that the HPA160 simply filters the air. It cannot add anything to air, give off gases, or produce any irritants by itself. It will not cause headaches. This model is perfectly safe and there are NO health concerns to worry about.

Using the auto-off timer feature

Honeywell HPA160 auto-off timer diagram
This is one of my favorite features and one that surprisingly much of the competition doesn’t have.

The auto-timer will switch off the purifier after 2, 4, or 8 hours have passed. It’s really easy to use. Just push the button marked with the clock symbol to set it to one of the 3 hour settings (2, 4, or 8 hours). After the time elapses it will turn itself off automatically.

Each time you push the button the indicator light for a selection will rotate through 2, 4, or 8 hours. Doing so a 3rd time will turn it off again. It’s so simple but so handy!

That’s a great way to leave it running when you’re gone during the day but won’t have to worry about running your electrical bill up.

The owner’s manual

Honeywell HPA160 HPA060 owners manual
The owner’s manual English section is only about a few pages in length. However it’s very clear and helpful. It covers the most important basic information you need to use and maintain your purifier.

What’s great is that it makes it easy to find the customer service telephone number if you need it.

In case you’re curious, here’s a download link for the HPA160 owner’s manual.

Noise levels during use

You might be thinking it could be a loud one. In fact not only is it very quiet – it’s one of the better sounding one’s I’ve tested so far!

Compared to the GermGuardian AC5000E or AC4825, for example, the noise had much less of a motor “whirr” and seemed more pleasing to me.

Three operational modes are provided: Germ, General, and Allergen. As I was testing it, it seemed as if those 3 operational modes corresponded to low, medium, and high respectively.

Turbo mode is definitely not low volume and isn’t suitable for sleep time. But it’s a great feature to have during times when you won’t mind it.

Volume measurements

Using this great little sound level meter to measure volume, I recorded the volume levels at 1 meter (3.28 ft) from the purifier.

Measurement/ModeVolume (dB)
Off (Room noise)39.3
Germ mode42.5
General mode47
Allergen mode53.2
Turbo mode57

In fact, it’s quieter than many smaller purifiers! That’s what surprised me a bit. And I’m very pleased with it, I have to say.

While turbo has a very noticeable volume level and “whoosh” sound, the other settings are very similar – and lower – than many other products on the market

It’s honestly very easy to forget it’s running when the high-speed Turbo is off because it’s so quiet.

Brightness levels in a dark room

Honeywell HP160 in dark room brightness
I’m fairly sensitive to light and sound when sleeping or relaxing at night. And I know I’m not the only one, so I make sure to check brightness levels in the dark. Blue LEDs like those used on this model are often too bright. This one was fine.

As one of my tests I used the model in a darkened room just like I’d use at night when sleeping. Overall, I found the indicator lights are not too bright.

However, just like any product with light emitting diode (LED) indicators, a little bit goes a long way. I could still a bit of light in the room and on the ceiling. If you’re sensitive to light like I am I’d recommend covering it up.

Unfortunately, this model doesn’t offer an illumination dimmer like the larger HPA200 does. That’s a shame because I’ve found it to be a great feature to have.

Final thoughts

So…after testing and owning the HPA 160, here are my thoughts. Overall, I really like it! It’s a great purifier that offers some very nice features and sounds so quiet and pleasing when in use.

I do have a few minor complaints. There’s no UV-C germ killing feature offered like in the AC4825 I reviewed here, for example.

Additionally, the lack of an illumination dimmer is a shame. However, it’s not a deal breaker and certainly isn’t enough of a concern to change my mind. Again, it’s a minor gripe.

If you’re looking for an excellent medium or large size air purifier that covers a recommended 170 square feet, it’s a great choice.

Don’t hesitate. It’s a great one, so head over to check the current price at Amazon.

  • Quality - 9.2/10
  • Value - 8.5/10
  • Ease of use - 9.7/10
  • Air cleaning ability - 9/10
  • Features - 8.6/10
  • Noise levels - 9/10

A very quiet, and very capable choice for medium or large rooms to 170 sq. feet. Well-made and a great performing model.

The HPA160 is a great choice! Simply put, it’s one of the nicer products I’ve tested and I enjoyed doing so. Well-made with good assembly and construction. Filters are easy to replace and readily available. Separate filter reminders are provided. Turbo mode is a bonus way to speed up air cleaning. I love the auto-off timer as well. It’s pleasing to the ear when running on standard speeds. I’d recommend it first to anyone not needing a germ killing feature.


  • High-speed Turbo mode for faster cleaning
  • High CADR rating – great purification efficiency
  • HEPA filters last approx. 12 months
  • Odor-reducing pre-filter is inexpensive
  • Pre-filter can be replaced separately
  • Carrying handle
  • 5-year limited warranty
  • Touch controls works well; buttons too
  • Built-in quick start guide
  • Customer support is good
  • Helpful owner’s manual
  • Auto-off timer shuts off automatically
  • One of the most quiet purifiers
  • Filter replacement is easy
  • Indicator lamp brightness is fairly low
  • Good build quality, fit and finish are nice
  • Filter performance is good, fresh air quicker


  • Auto-off timer only adjustable in 2, 4 or 8 hours
  • Manual doesn’t clarify the 3 main operational modes
  • No auto-sensing feature
  • Germ-killing feature not available like competitors
  • No illumination dimmer like the HPA200/300

Honeywell AirGenius 5 Vs True HEPA Purifiers – Review And Comparison

Honeywell AirGenius 5 vs true HEPA featured image

In my comparison and review of the Honeywell AirGenius 5 vs true HEPA purifiers I’ll show you how it stacks up against the competition. Although described as an “air cleaner” and an “odor reducer”, it’s actually extremely similar in many ways to other products you’ll find when shopping.

There are a lot of details to cover as it’s one of the best air cleaning products I’ve ever owned and reviewed. Read on and I’ll share with you everything you need to know before buying.

I’ll also tell you why it’s one of the best I’ve ever had the pleasure of owning.


Getting to know the AirGenius 5

AirGenius family air cleaners imageThe AirGenius 5 is one of 3 models in the AirGenius line from Honeywell and offers the most features of them all. If you’re budget-minded, the offering almost the same air cleaning performance for less money.

The AirGenius 5 (model number HFD320) is the top-level air cleaner in a family of 3. All 3 share the same physical size and same basic design (including oscillation). However, the HDF320 offers the most options including the highest fan speed available.

While both the HFD310 and the HDF320 provide a recommended 250 square feet of room coverage, the HFD300 is slightly lower at 225 sq. ft. Additionally, the AirGenius 4 is extremely similar to the top model, although without touch controls, fewer auto-off hour selections, and no germ reduction fan speed setting.

If money is tight but you’d love to have one of these air cleaners, consider the AirGenius 3. Its air cleaning performance is identical (aside from being limited in fan speeds). The trade-off is having fewer features, no accent light on the base, and no touch controls also.

Basic design operation

Honeywell AirGenius 5 3-stage cleaning diagram

The AirGenius 5 uses a 3-stage air cleaning process to purify the air. Unlike true HEPA air purifiers sold today, it also adds an ionizer field stage to capture additional air contaminants.

AirGenius purifiers are a bit different from competing products sold today in both the air cleaning methods they use and the ability to wash the filters for reuse.

Three stages are used:

  1. Washable basic (or odor-reducing) pre-filter section
  2. Permanent washable main filter stage
  3. Electronic ionizer stage

While stages 1 and 2 are standard in today’s products, what makes this air cleaner design different is that the filters are washable and can be reused. Unless an odor-capturing pre-filter is used (these can’t be washed – they must be replaced).

Both the pre-filter and main filter (called an “ifD” type by Honeywell) can be washed and re-used.

That’s a feature that’s very rare in today’s products, and offers the possibility of saving a substantial amount of maintenance costs over time. I’ll go into more detail about the filters later.

High air flow – just like a fan!

Because of the main air filter’s low-restriction design, high airflow is produced – it blows and circulates air much like a fan! That’s very unusual for an air cleaning product as most use HEPA filters which severely restrict air flow.

Additionally, the AirGenius cleaners have an oscillation option which allows circulating the room air even more rapidly.

At almost 27″ (68 cm) in height, it’s definitely not a small product.

Unboxing the AirGenius 5 and first impressions


Honeywell AirGenius 5 unboxing

Much like the other Honeywell purifiers I’ve owned and have tested, mine was solidly packaged and once again showed good quality from the get-go.

I’ve been looking forward to getting my hands on one of these ever since hearing about them, and it was fun opening it up!

The HFD320 ships with recyclable cardboard packaging and is securely held in place. It’s just a little tough to get it out of the box (as the bottom portion was very snug inside) but only took a moment or two. I had to pull it out while holding the bottom of the box.

After opening the box up I removed the plastic outer bag (you must turn the air cleaner upside to untie the wrapping) and moved on to check out the build quality.

The unit looked great, with no quality issues fresh from the factory. My first impressions were that of a well-made air cleaner that will work well just like the Honeywell HPA series I’ve owned. Good-looking and well-made products are what I’ve come to enjoy from the company.

And certainly I couldn’t wait to power it up and try it out!

How’s the build quality?

Honeywell AirGenius 5 up close image for quality

Build quality and fit and finish are good. The air cleaner has a nice-looking matter silver trim around the top. Mine was well-assembled and had no quality control issues.

My first impressions were right. I checked out the AirGenius 5 and verified build quality as I like to do when evaluating and testing air purifier products.

There weren’t any issues to mention. Gaps and seams aligned as expected (tightly) with no large spaces or loose body panels. The control panel (on top of the unit) aligns just as it should and looks great.

Note that the air cleaner arrives with a thin plastic protective cover you’re instructed to remove by the included label. However, you can leave it in place if you want to protect the surface. The touch controls work fine with it still on.

The body is a nice satin black color and looks good. The design style is similar to the HPA series of Honeywell air purifiers which feature similar trim, too.

Overall, I’m impressed with the build quality – it gives a good sense of being a well-made product.

Setting up the AirGenius 5 and first use

Honeywell AirGenius 5 box and included items image

After removing the air cleaner you’ll need to remove the packaging. Aside from that, it’s ready to go! Included is an additional pre-filter that’s optional and is used for odor and volatile organic chemical (VOC) removal. Unlike the pre-installed pre-filter, it can’t be washed and reused.

Actually, unlike some other brands and models, once unboxed and the packaging has been removed you’re ready to go.

Unlike some other purifiers including the Honeywell HPA series, you won’t need to remove filters from their bags before using the cleaner. The AirGenius ships from the factory with the ifD main filter and the ifD pre-filter (both washable) already installed and ready to use.

Optionally at this point, you can install the included type K filter (covered in more detail later) if you need odor and airborne chemical trapping ability. That’s an easy task, however: just remove the pre-filter from its bag and swap it with the pre-installed one.

Once the packaging is cleared away, simply pushing the power button brings the air cleaner to an on state. The air cleaner will begin running in mode 3 called “General Cleaning.”

Note that upon initial power-up and first use, a moderate smell will be present for some time due to the fresh filters. My unit took a few hours but it went away fairly quickly. That’s normal not just for this air cleaner, but I’ve seen it with other brands as well.

Note: A short-term odor is both normal and expected for many air cleaning products you buy. Much of this has to do with “outgassing” – the process by which materials release molecules into the air for a short time when new. Often this appears as some sort of mild chemical smell.

After a number of hours you’ll find it’s not very noticeable anymore and it will fade soon.


Honeywell AirGenius 5 (HFD320) specifications
  • Room size rating: 250 sq. ft (large rooms)
  • 5-speed fan control
  • Oscillating feature
  • Low-noise sleep mode
  • Main filter: Permanent washable high-flow ifD type
  • Pre-filter: Washable general purpose (installed) or K-type odor/VOC reducing (included)
  • CADR (Clean Air Delivery Rate): Smoke: 161, Pollen: > 160, Dust: > 170
  • Dual high-speed blower fans
  • Auto-off timer: 2, 4, 6, 8, 10, 12 hrs selectable
  • Electronic touch controls
  • Bottom accent light with 2 levels
  • Filter cleaning reminder
  • Replacement filter (pre-filter): type K (HRF-K2)
  • Power used: 65W (max.)
  • Carrying handle
  • Built-in operating reference card
  • Weight: 13 lbs (5.9 kgs)
  • Cord length: 6 ft.
  • Size: 9.97 x 9.92 x 26.81″ (25.3 x 25.2 x 68 cm)
  • Warranty: 5 year limited

As you can see from above its one of the more feature-packed air cleaners sold today. It’s rather unusual to have an auto-off timer feature with so many hour selections (6 selections). Most competitors offer about 4 or 5 at the most.

Additionally, a large range of fan speeds is nice.

Carrying and moving the air cleaner

Image of AirGenius 5 carry handle

Although the air cleaner is rather large and a bit heavy at 13 lbs, the built-in carry handle on the top rear is great. It makes moving it from place to place much easier. It’s a good feature to have.

Fortunately, despite its large size and somewhat heavy weight there’s a convenient feature Honeywell has provided. Just like many of their other air cleaning products, there’s a carrying handle located on the top rear portion of the body.

Note that other manufacturers like GermGuardian provide the same feature on their most popular air purifiers as well.

Air cleaning ability and performance vs true HEPA filters

CADR ratings

Honeywell AirGenius 5 CADR ratings label
The Clean Air Delivery Rate (CADR) rating label for the AirGenius 5. This is a lab-tested and proven rating of cleaning effectiveness, where a higher rating is better. The HFD320 scored well in all 3 standard tests!

As this is a rather different type of air cleaning product, I can’t stress enough how important it is that the company can back up their air cleaning claims. I say this because as the AirGenius 5 uses a high-flow permanent and washable main air filter, it’s not a High Efficiency Air Particulate (HEPA) filter as most purifiers use.

Fortunately, the company offers lab-proven air cleaning data provided by the industry standard Clean Air Delivery Rate (CADR) ratings. The CADR rates air cleaning products on 3 types of common air quality problems: tobacco smoke, dust, and pollen.

Essentially, products are tested in a lab environment of a fixed size and the amount of air particulates removed in a given amount of time is measured. This gives a CADR rating where higher is better.

The AirGenius 5 does quite well in all 3 tests! (For reference, some of the most popular air purifiers have CADR ratings of about 100, so that shows you how effective it is!)

AirGenius 5 vs true HEPA filter performance

The AirGenius 5 is rated to provide a reduction of 99.9% of airborne elements down to a microscopic 0.3 microns in size – which is nearly identical to HEPA filter performance. (Note that 1 micron, or 1 micrometer, is 1/1,000,000 of a meter in size).

Originally I was concerned about the company’s claims that while it’s not actually a HEPA filter it’s basically just as effective. However, the data backs it up as well as my own experiences.

The biggest difference is that while more particulates may pass through on the first pass, the AirGenius 5’s airflow rate is so much higher that it makes up for the difference. In my testing so far I’ve been very happy with the results.

Ultimately, for the majority of most air quality problems the ifD filter essentially meets the same standards as a true HEPA filter but allows air to circulate faster (hence the higher CADR ratings).

HEPA filters are very dense in construction and restrict airflow quite a bit. In order to have faster airflow, air purifiers using them require even faster and noisier electric fan assemblies.

What kind of filters does it use?

AirGenius 5 included filters image

The AirGenius 5 ships with 2 filters pre-installed and ready for use: 1) the washable ifD filter and 2) the general-purpose washable pre-filter. Included in a sealed bag (not shown here) is an optional pre-filter for odor control and capturing VOCs.

From the factory, a general-purpose pre-filter (washable and reusable) is installed as well as the main ifD permanent filter.

The type K filter, should you need odor and airborne chemical vapor control, is included in a sealed bag. The pre-filter is easy to remove and swap. It’s just a matter of opening the rear cover, pulling it out gently, and inserting one back underneath the plastic tabs.

Main filter comparison: AirGenius 5 vs true HEPA filters

AirGenius 5 vs true HEPA filter comparison image

The AirGenius 5 (and other models in the same family) use a ifD filter (top) which allows high airflow unlike true HEPA filters (bottom). The ifD filter serves as the main filter and resembles a honeycomb or car radiator in design. True HEPA filters like the one here shown from a popular GermGuardian AC4825 purifier use a very dense fibrous material which restricts airflow.

The main filter is called an “ifD” filter by Honeywell. It’s best described as a “honeycomb” type of design: open passageways through which light can be seen. It’s made of dense fibrous material.

HEPA filters, however, use filter material densely packed with incredibly small fibers that is folded and held in a rigid plastic frame that snaps into the body.

In the case of the HFD320 (and the other similar models), it’s an effective filtering solution that allows the cleaner to circulate air in the room much faster than most products can. Additionally, it meets the basic requirement of the HEPA standard: capturing elements down to 0.3 microns in size.

At 99.9% efficiency, it’s not quite as good a performer as a HEPA filter (99.97% cleaning efficiency), but that’s extremely close!

Washing and re-using the permanent filter

Honeywell provides an estimated life span for the permanent ifD filter of about 5 years, with 4 washes and reuses per year.

It’s pretty simple to clean: remove it from the unit (when turned off) and wash gently in warm soapy water for 2-3 minutes maximum. Remove and allow to dry fully before reuse.

I found it easy to clean. Having a reusable filter is a nice surprise as so few air cleaners offer that. It’s rare.


Honeywell AirGenius 5 pre-filter image closeup

The factory-installed general-purpose pre-filter viewed up close. It’s a mesh-like material that’s essentially similar to open-cell foam or sponge material. It’s good for dust, pet hair, and so on, but can’t absorb odors and volatile airborne chemicals. However, unlike other brands, this one can be washed in warm soapy water and reused. 

From the factory, the AirGenius 5 comes ready to use with the general-purpose pre-filter section already inserted in the rear cover. It’s mainly good for common air quality nuisances like pet hair and dust (which is a problem where I live, I might add!).

A huge benefit this is its ability to be re-used, as that’s not common for most air cleaning devices sold today in case you weren’t aware. Ordinarily most require buying replacement filters periodically.

Cleaning for re-use is easy: periodically remove it and shake it, vacuum it, or you can rinse it under warm water. Let it dry fully before installing it back in the unit.

AirGenius 5 pre-filter type K image

Included in the package is a type K pre-filter which can be swapped out with the factory-installed pre-filter. Type K filters are used for trapping odors and other airborne chemical substances but must be replaced periodically. They can’t be washed and reused.

Included with the air cleaner is a sealed bag containing a type K (replacement model HRF-K2) filter. If you need odor and airborne chemical vapor absorption for your home, you’ll need to install it in the place of the original one.

The K filters use potassium permanganate calcite to trap some odors and gases and fumes.

Of course, it’s just as good for dust, pet hair, and similar debris as the original but it’s also treated with odor-absorbing materials with a limited life span.

Honeywell recommends replacing this filter about every 3 months if used.

The ionizer section

Ionizers use an electrical charge to cause airborne particles to be pulled from the outgoing airflow. As a side benefit, they’re also effective against airborne germs and have been documented to reduce sickness-causing viruses and other microbes.

Unlike other products sold as “air purifiers” that use only an ionizer, the AirGenius uses it as an additional cleaning feature – not the primary one. That’s the job of the first two stages. And accordingly, there are no metal collection plates to clean.

It does, however, produce a tiny amount of ozone which I’ll cover below.

Removing filters for cleaning

AirGenius 5 filter removal diagram

Filter removal for maintenance is actually really very simple. You’ll only need to do the following:

  1. Push on the rear cover release
  2. Pull the rear cover backwards at an angle
  3. Remove the permanent filter using the tab shown in #3 above

The pre-filter is really easy to remove from the cover/grill: it’s very soft so just gently pull out one edge from the retaining tabs.

Removing the permanent filter isn’t hard either. Much like the grill, it “hooks” using tabs on the bottom of the filter frame. Pull from the top finger/removal tab and move it out in a downward motion.

Note! The plastic rear cover has a central tab that could be broken if you’re too forceful. Be sure to “swing” the cover out gently when opening the air cleaner.

Filter reminder feature

The built-in filter reminder will indicate when the (estimated) time for cleaning your filters has elapsed. It’s easy to reset as well once you’ve cleaned and replaced the filters.

With the power off, just hold the filter replacement button for about 3 seconds; the indicator will illuminate, indicating it has been reset.

Filter life and costs – a big advantage!

One thing that struck me was the amount of money you can save thanks to its design. For example, most HEPA purifiers recommend a filter replacement every 6-8 months or so depending upon use.

Here’s an estimate of how much money you can save with the AirGenius 5 (assumes a permanent filter life of 5 years, and using the basic pre-filter). I’ll calculate this based on a reasonable average filter replacement cost for most purifiers. Let’s use $27 as a reasonable number:

5 years x 2 replacements per year x $27 = $270.

That’s quite a bit of money – and amazing considering it’s more than you paid for the air cleaner itself! Of course, if you need odor control or chemical vapor control you’ll need to use the replaceable type K pre-filters.

Those sell in packs of 2 for near $15 or so, which is roughly $75 in maintenance costs for 5 years. That’s excellent!

Does the AirGenius 5 produce ozone?

The short answer? Yes. However, no need to worry! It’s a tiny amount and unlike other products I’ve tested, I can’t even detect it. Ozone, when present in sufficient amounts, is usually easy to smell and recognize.

Ionizers work by using high voltage to charge unwanted airborne particulates and draw them out of the air. This, by nature, creates a very small amount of ozone as a by-product. Don’t confuse this with ozone generators which produce heavy amounts of ozone that are bad for you.

According to Honeywell: “This product complies with the maximum allowable concentration of ozone of 0.050 parts per million by volume in a 24 hour period.”

Basically, the AirGenius does not produce unsafe or unpleasant levels of ozone – it’s well below the safe and undetectable threshold for people.

The owner’s manual and reference guide

Owner’s manual quality

Honeywell AirGenius 5 owners manual image

I found the owner’s manual to be well done, covering the HFD300 series of air cleaners with pretty good detail. It covers basic operation, safety information, maintenance, and provides a telephone number should you have questions.

Overall it’s clear and well-done, just as I’ve come to expect from other Honeywell purifiers I’ve owned and reviewed.

Built-in reference guide

AirGenius 5 Quick Reference Guide image

A nifty little feature, the built-in reference guide is provided to help with basic operations and  consumer help contact information. It’s located near the carry handle area and simply pulls right out. Pretty neat! I like this little touch.

One cool little addition I found on the AirGenius is the built-in Quick Reference Guide. When looking down while above the control panel, a small plastic tab can be seen near the top rear of the unit.

Pulling it out reveals a laminated plastic card with basic instructions, a consumer telephone line, and an email address for getting assistance. I’ve seen this on other Honeywell air cleaning products but not on most competitor’s products.

Controls and fan speeds

AirGenius 5 control panel image

The HFD320 features touch controls and many options including 5 fan speeds. I found it very easy to use and a pleasure to own and enjoy every day. It also features more auto-off hour settings than others. However, there’s no memory feature, so upon powering it off and on you’ll have to set it back to your last selections.

The AirGenius 5 features a very sleek-looking and well-designed touch control panel. Note that several others in the same product family don’t offer touch controls. The AirGenius 4, for example, doesn’t and also doesn’t have as many timer options as the AirGenius 5.

Operating the air cleaner

Using the air cleaner is really simple: just push the power on/off button and it will enter General Cleaning mode with medium fan speed. By default, the oscillation feature is switched off.

Touching any button on the panel rotates through the settings easily. For example:

Purification level (fan speed): Sleep > Germs > General > Allergen > Max. > Sleep

The accent light, located at the base of the unit, is set to high brightness by default. However, it’s not too bright and you may not need to change it. There are 2 brightness levels (as well as off) available.

One complaint I have is that unlike some other models I’ve tested, there’s no brightness dimmer for the controls themselves. I don’t understand why.

Additionally, there’s no memory feature to retain your last operational settings after it’s turned off and then back on again.

Note that the unit doesn’t beep when operated unlike some the nice Honeywell HPA200 and the popular Levoit LV-H132 air purifiers I’ve both owned and reviewed.

Fan speeds and airflow

While Honeywell describes the various operational modes as being correct for particular air quality issues (like germs and allergens) they don’t go into detail about them. I would have liked to know more.

As I mentioned earlier, unique to the AirGenius line is the high airflow rate. I can feel the air blowing from across the room. When oscillating is switched on quite a bit of air is moving.

When set to Max, it’s as if you’re using a small fan in the room. It’s an interesting experience and I have to say I like it. I realize, however, that not everyone wants a large amount of air blowing towards them.

In that case, you can simply leave the oscillation setting off, although using it helps circulate and clean air more quickly and effectively.


I’ve owned oscillating air fans in the past, so I’m not unaccustomed to having one in the room. However, I wasn’t sure how I’d feel about having an air cleaner behave similarly.

After some time, however, it has really grown on me. Having the air circulate and become fresher by the moment is great. Here’s a short video clip I took demonstrating its operation.

Honeywell AirGenius 5 oscillating video

Noise levels during use

I used a great little sound level meter I found at Amazon to measure volume. My measurements were made at 1 meter (3.28 ft) from the purifier.

Measurement/ModeVolume (dB)
Off (Room noise)39.3
Sleep/Quiet mode41
Germ Reduction mode42.7
General Cleaning mode45.5
Allergen Reduction mode48.4
Max. Cleaning mode50.6

By comparison, competing products are near 55dB or so when on maximum. The AirGenius 5 is nearly 6 decibels quieter which is a fair amount of difference. Even some of the smallest air purifiers are well above 44dB on their lowest setting!

All in all, despite its large size and high airflow rates, it’s one of the quietest air cleaning products I’ve tested.

I’ve been testing the unit in my room where I sleep with it set to Sleep mode. Although I’m sensitive to both light and sound levels, I slept comfortably with it – it’s very quiet!

Accent lighting and brightness levels

AirGenius 5 night brightness images and comparison

A lovely accent lighting feature on the base of the unit is built-in (top) and adds a soft glow around it. I found brightness levels to be good and not TOO bright for my tastes, despite being a sensitive sleeper. The control panel illumination (bottom) is a bit brighter than I would have liked. Sadly, there’s no way to adjust that.

The HFD320 has a great little feature I haven’t seen in other products: there’s a classy accent light at the base of the unit. When switched on, it provides a nice, soft blue glow around the base of it.

2 brightness levels can be selected. Somewhat like the night light provided by the best-selling Levoit LV-H132 it provides a way to find your way to the bathroom late at night.

As part of my standard testing process, I used the air cleaner during my normal sleep sessions to judge both sound levels and brightness in a darkened room. I’m a light sleeper and as such, I notice the glow of just about any electronic device. And I’m sure I’m not alone.

The controls are moderately bright. It wasn’t enough to keep me from being able to sleep well, but definitely brighter than I would like.

Oddly enough, other air cleaning products by Honeywell offer a dimmer for the controls – but not this one. That’s unfortunate, but not a big deal when compared to the overall value and quality of the unit.

Honeywell vs GermGuardian products

Honeywell vs GermGuardian comparison image

A general comparison of the AirGenius 5 (left) next to 2 of the best-selling competing products on the market. (Center) the GermGuardian AC4825 medium room purifier and (right) the AC5000 large room purifier. Both GermGuardian products use true HEPA filters.

As you’re likely to run across GermGuardian products as an option when shopping, I’d like to provide some additional helpful information. Comparing the two brands is much harder unless you’ve owned and tested them.

Having owned many models from both brands, I can tell you that the quality of both is comparable. Pricing and value are a bit more difficult to compare, however, because room coverage isn’t exactly the same between competing similar models from the two brands.

Comparing the two brands, in general

Basically, GermGuardian uses true HEPA filters and they’re some of the best affordable air purifiers sold today. With the exception of a few models, they are, however, a bit more “basic” in design: most use simpler controls and have fewer features.

Honeywell, on the other hand, offers models with electronic controls, auto-off timers, and so forth. The HPA series of air purifiers are a good example.

In the case of the AirGenius 5 it’s hard to compare it to current GermGuardian products although the AC5350B with electronic controls and 193 square feet of coverage is one of the closest.

The most significant differences to be aware of between the 2 brands are:

  • GermGuardian products offer a UV-C germ killing feature; Honeywell does not
  • Advanced features like oscillation and touch controls are available on Honeywell products
  • GermGuardian purifiers use true HEPA filters with a slight advantage in air cleaning
  • Better warranty length for Honeywell (depends on the model)

Final thoughts and review score

All in all, the AirGenius 5 (model HFD320) is one of the nicest air cleaning products I’ve had the pleasure to own and test. Build quality is great and a nice assortment of features really make it a true winner. It’s also one of the quietest I’ve tested and measured, despite moving so much air.

Having an air cleaner with air flow similar to a fan may not be for everyone, but it’s one reason why the HFD320 has some of the best lab-proven clean air delivery rates and 250 sq. ft. of coverage. It holds its own when compared to true HEPA-based air purifiers, too, with almost the same air cleaning efficiency.

Having washable air filters is a rare and nice money-saving feature, too. However, its cleaning ability, while pretty good, still can’t match that of a true HEPA purifier. 

If you’re dealing with pets, smoke, or other very bothersome air quality problems I’d recommend a good quality HEPA purifier.

However, for average homes, it’s a very nice little air cleaner that’s well worth your money. While it’s a bit expensive in stores locally, you can find the great buyer reviews and a much lower price over at Amazon.

  • Quality - 9.5/10
  • Value - 9.5/10
  • Ease of use - 9.5/10
  • Air cleaning ability - 7.9/10
  • Features - 9.8/10
  • Noise levels - 9.8/10

Great features, good air purification, and a unique take on air cleaning. One of the nicest products I've tested.

The Honeywell AirGenius 5 provides near-HEPA air cleaning ability with great features and performance. It’s also one of the most quiet air cleaning products I’ve owned and reviewed. Using an original design, both the main and pre-filters can be washed and reused, saving a good bit of money in maintenance costs. However, it’s not as effective for heavy smoke and allergens as some of the top competitors, but it’s great for average homes.

The oscillation feature combined with the high airflow rate circulates and cleans air in a room quickly and pleasantly. CADR rates are very high; with 255 sq. ft. of coverage it’s great for just about anyone. Build quality and documentation are both highly satisfactory as well. Well worth your time and money!


  • 99.9%, 0.3 micron air filtering quality
  • Washable/reusable filters
  • Includes odor/VOC absorbing pre-filter
  • 5 speed/cleaning levels
  • High air flow
  • Great CADR ratings (160+)
  • 255 sq. ft. room coverage
  • Low (quiet) sleep mode
  • Near-HEPA cleaning efficiency
  • Below-average noise levels
  • Good build quality
  • Touch controls
  • Accent lighting w/ 2 levels
  • Auto-off timer with 6 hour settings
  • Oscillation feature
  • Filter reminder
  • Easy to use
  • Carrying handle built-in
  • Good owner’s manual
  • Built-in ionizer in 3rd stage
  • Filters are easy to remove and install
  • Pull-out reference card
  • 5 year limited warranty


  • Washable pre-filter can’t capture odors/fumes
  • No memory feature
  • No dimmer or off for control backlighting
  • No Bluetooth or Wi-Fi connectivity
  • Not currently available in other colors
  • Slightly less efficient than true HEPA cleaning
  • High air flow fan output not suitable for some
  • Tower size design not suitable for all locations
  • Controls will be a bit bright for some at night
  • No germ killing feature offered