Buyers guide

GermGuardian AC4825 VS AC4900CA – A Detailed Comparison Of Two Excellent Air Purifiers

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! These are two of the best-selling air purifiers on the market today so it’s definitely worth finding out more before spending your money.

I’m a proud GermGuardian product owner myself so I’ve decided to share my first-hand knowledge with you as well as giving you 100% of the information you need straight and without trying to persuade you one way or the other.

Both air purifiers 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.

Contents

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 compae 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 technical 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 away 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 afterwards.

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 an 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 coves 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. So the AC4900CA’s sleek, modern styling isn’t alone in that regard. Personally I prefer the cool & updated 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 AC5900CA and AC4100 instead of the AC4825.

Size, performance, and noise levels

Size

Size-wise, there’s very little difference. Both are just under 22″ in height. There is a 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/Speed AC4825 Volume (dB) AC4900CA Volume (dB)
Off (room noise) 39.3 39.3
Low 42.5 42
Medium 50.5 51
High 58 58.3

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.

Accessories

LB4000 UV replacement bulbGermGuardian FLT4825 replacement filter

The 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.

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.

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 air flow 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 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 many 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 Type AC4825 AC4900CA
Blinking blue light (UV-C glow trim blinking) UV bulb needs replacement (UV light blinking) UV bulb needs replacement
Red blinking light Filter needs check/replacement Filter needs check/replacement

Filter replacement

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!

Controls

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

Have a look at the photos I’ve taken here:

GermGuardian AC4900CA controls imageAC4825E top 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):

Model: AC4825 AC4900CA
Current price: $79.99 $79.99

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 in my experience, with the glowing blue front trim, tends to illuminate the room a bit at night even though it’s not very bright. It’s especially true because the human eye is very sensitive to blue light.

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

Image
GermGuardian AC4825 3-in-1 Air Purifier with True HEPA Filter, UV-C...
GermGuardian AC4900CA 3-in-1 Air Purifier with True HEPA Filter, UV-C...
Model
GermGuardian AC4825
GermGuardian AC4900CA
Room Coverage (Sq ft)
155
155
Size
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
Warranty
3 yrs limited warranty
3 yrs limited warranty
Replacement Filter
FLT4825
FLT4825
Replacement bulb
LB4000
LB4000
Image
GermGuardian AC4825 3-in-1 Air Purifier with True HEPA Filter, UV-C...
Model
GermGuardian AC4825
Room Coverage (Sq ft)
155
Size
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
Warranty
3 yrs limited warranty
Replacement Filter
FLT4825
Replacement bulb
LB4000
Image
GermGuardian AC4900CA 3-in-1 Air Purifier with True HEPA Filter, UV-C...
Model
GermGuardian AC4900CA
Room Coverage (Sq ft)
155
Size
8.875 x 7.125 x 21.75"
Difference Vs. Other Model
UV-C indicator is small LED, front-facing controls, modern style
Warranty
3 yrs limited warranty
Replacement Filter
FLT4825
Replacement bulb
LB4000

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.

Your comments are welcome!

Leave a reply

CommentLuv badge