What Humidity Should I Set My Dehumidifier To?

Humidity can be a huge factor that really impacts your home’s comfort. It can also contribute to a lot of problems if not dealt with.

The good news is that a dehumidifier can help tremendously.

But what setting should you use? If you’re wondering, “What humidity should I set my dehumidifier to?” you’ll find what you need to know here.

Home air quality is very important to me and I believe everyone deserves to enjoy great comfort at home. I’d love to help you so I put together this useful guide which explains humidity and much more.

Infographic – Dehumidifier facts and settings

Infographic - what humidity should I set my dehumidifier to

Humidity levels in your home

Image of a woman sweating and cooling with a fan due to high humidity
High humidity can make you very uncomfortable and sweat much more than normal, even in relatively normal temperatures. One reason for this is because your body can’t cool itself the same way as when in a lower humidity environment. A dehumidifier can help a lot by bringing the moisture level down to a far more comfortable level.

The truth is that there is no “perfect” humidity level – there is, however, a good range of humidity settings you can use as a guideline. Also, don’t worry too much about getting the settings exactly right. That’s not critical. We’re aiming to get it in the right approximate range, basically.

What we’re looking to do is bring down the humidity where you live or in your basement to a level where:

  1. Problems like mold, moisture-related odors, and dust mites are controlled
  2. You feel comfortable

With these 2 goals in mind, let’s continue.

What is humidity?

Relative humidity comfort scale image diagram

Relative humidity, as shown in the scale above, directly affects the comfort you feel when exposed to the air both at home or outside. Most people feel their best when the humidity around them falls within a certain range: generally 30%-60%. If the humidity level is too low, we feel the symptoms of dry air. If it’s too high, we may feel very hot and become subject to overheating and excessive perspiration. (Note: there are secondary problems caused by the humidity being too high – see below)

The term humidity is used to describe the amount of moisture, expressed as a percentage, in the air around us.

There are actually a number of different scientific terms used to describe it depending on different criteria, but let’s not make it more complicated than it has to be. When it comes to most situations and especially your home, we’re concerned with relative humidity.

You may have noticed that some time after it rains your windows fog up from moisture and you feel a bit warmer. That’s exactly the same effect – if the humidity rises a lot you feel much less comfortable and even though it’s not really warmer, it feels warmer.

Additionally, high humidity levels bring a number of secondary problems that homeowners sometimes experience like mold and dust mites.

Respiratory infections and sinus issues, as well as diseases associated with viruses and bacteria, are increased when the level falls below 30%. Also, if you have a cold or other illness, it’s more difficult to recover without a healthy humidity level in your home. I’ve experienced this firsthand!

Relative humidity

Bottle of water with condensation in humidity example image

Condensation is the collection of nearby water vapor on objects that cool the air around them. You may have observed this on a cold drink bottle, for example. In especially humid areas the amount of condensation is even higher. Likewise, when the area around you is excessively humid the moisture can react with and affect nearby materials, promote unhealthy air, encourage dust mite growth, and affect your body.

Relative humidity is a way of expressing how much water vapor (moisture) is in the air depending upon the current temperature. This is because as temperature increases, the amount of moisture the air can hold increases. And likewise – when the temperature decreases, the amount of moisture it can hold decreases.

Ideally the comfort range – the range in which most people feel pretty good – is about 30% to 60% approximately. The truth is, what feels best to you depends on you and varies from person to person.

A great rule of thumb is to think of about 50% as a good upper limit for both in your home and basement. Under 60% is necessary to control or prevent mold growth. In order to reduce or prevent dust mite problems, you’ll want to keep it under 50%.

So, for several practical reasons, around 45% is a good setting for your dehumidifier.

Note that you should always check the minimum operating temperature of your humidifier. Be sure you don’t attempt to operate it at a lower temperature than it’s rated for.

Basement dehumidifier settings

hOmelabs dehumidifier in basement image
Basement humidifiers like this popular hOmeLabs dehumidifier model can prevent mold, keep “musty” odors under control, and make your additional basement space safe for breathing. Many dehumidifiers have attachment points for drain hoses which can be routed to a drain or sump pit to avoid having to the water collection container.

Basements are quite a bit different from the rest of your home. This is primarily due to being surrounded in most cases by soil that’s high in moisture. Because of this, humidity levels down there are a source of odors and mold if you don’t take action.

Windows that aren’t sealed properly are also a source of additional humidity from the outdoors. Don’t overlook this. If your basement is exposed to a constant source of moisture from outside your humidifier will have to work constantly.

That’s definitely a problem! This means your electric bill will be high and your dehumidifier’s life span will shorten. Not to mention how much water you’ll have to dump from the container if not using a water removal drain setup!

Set it right to protect your basement & air quality

Mold tends to be a problem at humidity levels above 60%. You’ll want to be sure to keep your basement dehumidifier at 60% or less at a minimum.

Ideally, however, the best setting is around 50% or so. Set yours to that and observe how long it runs before making an adjustment. If it runs continuously (never shuts off) or never seems able to reach the desired setting, it’s time to look further. There’s a good chance you have sources of additional air leakage which allow more moisture to enter your basement.

If additional outside air is allowed to enter your basement the dehumidifier will have to work much longer and much harder than it otherwise should. This also means your electric bill will rise, too!

Also, be aware of what’s happening with your dehumidifier during colder temperatures, as if the temperature drops below 65°F (18.3°C) it could potentially freeze up.

The good news is that once your dehumidifier has had some time to operate and the humidity level has come down, you’ll notice an improvement in the typical “musty” odor found in basements. Mold growth will also halt, although that’s not always visible readily.

You’ll notice that the air is better for breathing and you can put your basement space to better use afterward.

Home dehumidifier settings

Dehumidifier in living room example
Much like a dehumidifier you can use in your basement, they’re very helpful in your home’s living areas as well. They are extremely effective in high humidity areas and during humid seasons or environments. A dehumidifier can bring comfort back to your living spaces. They’re also especially great if you don’t have air conditioning but suffer from warm air with high humidity. Shown here is a great choice, No products found.

For your home’s living spaces, it’s not so much different from what you’d set a basement dehumidifier to, but there is a little bit more to consider.

It’s not just about comfort!

Unlike basements, bedrooms, living rooms, or any other area where humans and pets reside are prone to dust mite problems. Dust mites reproduce and thrive at humidity levels above 50% or so. They’re a major source of allergies and are an extremely common issue as they feed off of human & pet skin cells.

They’re found most commonly in fabrics & materials where humans and pets reside, like beds and couches.

Dust mites – sometimes called bed mites – are the most common cause of allergy from house dust. Dust mites live and multiply easily in warm, humid places. They prefer temperatures at or above 70 degrees Fahrenheit with a humidity of 75 to 80 percent. They die when the humidity falls below 50 percent.American College of Allergy, Asthma & Immunology

Knowing this, I recommend you keep your home’s dehumidifier at no higher than 50%.

Feel free to adjust it lower if needed. After all, your comfort is a personal preference. Just bear the guidelines in mind if you’re suffering from allergies or other respiratory problems.

Use a dehumidifier to reduce the humidity in your home below 50%, making it a less suitable environment for dust mites.

The optimal range for a home dehumidifier is to use a setting between 30%-50%, based on your comfort. 45% is reported by many people as ideal.

Note: You can also use an air purifier alongside a dehumidifier to deal with dust mites, pet dander, or other air quality problems. There’s no problem using them both together for healthy and fresh air.

Dehumidifier settings table

Here’s a simplified table containing the dehumidifier settings you should use:

Type/LocationDehum. SettingsNotes
Basement Set to 60% or below. 45-50% are good settings to use. To control mold, keep below 60% humidity. Be sure to observe dehumidifier. If running continuously, check for air leakage allowing outside humidity to enter basement. Don’t use dehumidifier at low temperatures (ex.: winter)
Home/Living areas Set to 30-60% for desired comfort range. 45% is a great target for most people. Set dehumidifier to 50% and below to keep dust mites from thriving. Adjust to below 50% based on comfort level. use 45% as a general guide, as is suitable for many people. Reduce use in winter as humidity will drop with cold or when heat is in use.

Additional information

Are you interested in learning more about what humidifiers do? They’re a great help when the humidity is too low like during the cold winter months. Here’s my excellent post about what humidifiers do and how they can help you. You’ll find some suggested models there, too.

If you’re also in need of better air quality, you can find some of the best-rated yet affordable air purifiers here as well.  I own and personally recommend the best-selling GermGuardian AC4825 and I’ve written an extensive review here.

Have any questions or suggestions? Feel free to contact me or leave a comment!

Your comments are welcome!

  1. Your help looks to be brilliant _ just what I’ve spent a couple of frustrated days trying to find without success; and now I look to have found exactly what I need. Thanks for what I’ve learned already. I’ll contact you again if I can when I’ve read more of your site and put what I will have learned to the test.

    Best wishes, Bob Moy

    Reply
      • Hello Grant,

        Thank you in advance for taking time out of your busy schedule to answer my questions.

        Thank you again for all of the great information on the web.

        Is it okay to run dehumidifiers in the basement now, during Ohio extreme rainy season in late April and May.
        I set them at 50, humidity setting.
        I place one in the finished area and one humidifier in the area for storage. About 2000 sq. feet of space. Both are 70 pint Frigidaire. Older remodeled custom ranch home with plaster walls throughout.
        The outside temp is only 55, 60 to 70 during the day most of the month of May.
        We have had tons of rain so far and my basement is dry.
        I was concerned that the outside temp was not warm enough.

        Wishing you great health and continued success! Mark

        Reply
        • Hello Mark & thanks for your kind words! I do appreciate it. :)

          I assume your dehumidifiers are automatic, is that right? (ex.: they’ll switch on only when the humidity is above the humidity setting, then switch off after it’s back) Yes, you can run them now if you like.

          My advice, though, would be to get one or more inexpensive humidity gauges (even under $10 they’re pretty accurate) and monitor the humidity in your finished area & storage area to see if it’s really needed during given temps & rain conditions. That’s because it might not be needed.

          It really depends on your particular home & storage area how much moisture gets indoors and then if the dehumidifier needs to run. I asked about the automatic feature because in that case, it’s not really a problem, but if they’re not you wouldn’t want to run them more than necessary to keep your energy use down.

          So I would check the humidity with some inexpensive gauges periodically, especially after it rains, and see when you really do need to run them, then do that (especially when those areas hold humidity a long time). Otherwise, run them whenever you like. Good dehumidifiers will stop after they reach the humidity level you set.

          I would expect you’d need them after heavy rains when it’s in the 70s and above, generally.

          Hopefully this helps, and all the best to you, too!

          Reply
    • I still don’t know what to do to stop my dehumidifier from freezing up! No one can seem to till next that. It’s set at 50 percent but freezes up after a couple of days. It’s in the basement.

      Reply
  2. my basement is underground all walls plus there is a crawl space under kitchen. i run a dehumidifer and it stays at 51 will not go any lower and seems to run all the time. can my crawl space be my problem and what can i do

    Reply
    • Hi John. Yes it sounds like the crawlspace (or rather the moisture entering through from outside) is the problem. I assume you meant the dehumidifier is in the basement.

      I would turn the dehumidifier up a little bit to somewhere above 51%, for one thing. If you’re not staying in the basement or crawlspace for any reason 60% will help the dehumidifier not run as much.

      You will probably need to look into blocking moisture from coming indoors from outside. Have a look here for some good examples: 12 Affordable Ways to Dry Up Your Wet Basement For Good!

      Reply
        • Hi Jessy. In that case, yes if it’s cooler outside you can open the windows. But it would be ideal to turn off the dehumidifier while doing that or you’ll be wasting energy (unless yours has auto operation and will shut off when it reaches the humidity level you set).

          Reply
  3. Hi Grant.

    This is great info but running 24/7 is costly. I was going to set up a wifi plug to limit the times it runs.

    What do you recommend? I was thinking the hours we are active in the home or would that defeat the purpose?

    Thanks

    Reply
    • Hi, Jimmy! When you say “wifi plug” I assume you mean a remote on/off control of some type? Yes, I think it’s worth a try, perhaps running it most of the day then off when you’re out.

      I’ve used inexpensive auto on/off timers with standard or digital controls to do the same for heaters and fans for the same reason. Those are usually $10-$15 or so, so that’s another option to consider. Give it a try (don’t spend too much money up front) to see how it works and if it works well in your case.

      Also, you might consider what you can do to reduce or prevent the humidity source in the first place. Here’s a post with some ideas you can take a look at (I’ll update my information with some of those, too).

      Have a good day. :)

      Reply
  4. Hi. I’ve just purchased a dehumidifier as we dry washing in our home daily on airers and both my husband and son usually shower for at least 30 minutes each time, resulting in dripping walls. My bathroom ceiling is covered in black mould and I’d like to redo it. Would it be advisable to use the dehumidifier after each shower and when drying clothes or would I need to put it on more often? Once I’ve redone the bathroom ceiling I’m hoping I won’t have to do it again for a long time. Thank you.

    Reply
    • Good morning, Jenne. Sounds like you have a lot of moisture trapped!

      It would be ideal to use the dehumidifier not just after showering but also before and during it. The best way to know what’s going on is to get an inexpensive humidity gauge, as they’re often under $10 and work well. As a bonus they usually have the temperature displayed too.

      That way you can see when you need to use the dehumidifier (when the humidity level is high, ~60% and above). A shower will put out moisture faster than a lot of dehumidifiers can remove it so you may need to leave it running for some time.

      Hopefully you’ve just got a buildup of mildew and not mold, like in this article about mold vs. mildew.

      Reply
  5. Hi, I use my Tatung dehumidifier in a wooden garden shed where I store a lot of office paper records. The Tatung has settings of Lo or Hi, I guess you are saying I should set it about midway but slightly nearer the Lo than the Hi? Simon

    Reply
    • Hi Simon. I tried but didn’t have any luck finding an owner’s manual for the Tatung online before I replied.

      Basically, it depends if Lo or Hi mean for low humidity & higher humidity, or lo mode (lower humidity reduction) or higher humidity reduction. It’s hard to say without more information.

      If low is under 60% humidity, then yes I would use that.

      Reply
  6. Hi Grant i have a timer on my humidifier and what ever i have it set at, it doesn’t seem to want to come back on. I would prefer for it to run longer at a time, it only runs for about 5 minutes and shuts of again! Can you please tell me what i might be doing wrong with the timer?

    It is a Frigidaire. I would really appreciate some help trying to get some humidity out of the family room Thank you

    Reply
    • Hello, Rosemarie. I can’t comment in more detail since I don’t know the model number, but I think it may be a problem with what you’re setting it to. If not, then it’s possible it could be a problem with the unit (although that would be less likely I think).

      If you have the owner’s manual (or can find it online) you can check what your timing options are. Usually there’s a time adjustment button or in some cases you push the timer button repeatedly to select the time-off period.

      Hopefully it’s just that you’re not setting the timer to a higher setting.

      Reply
  7. Hi Grant, I’ve a dehumidifer in my unfinished basement. This dehumidifer has a ‘Continuous Dehumidifying Operation’ mode, to run it 24/7. Is this recommeded for an unfinished basement which is about 3 years old. the humdifier model is Comfort Aire BHD-301-H.

    Thanks.

    Reply
    • Good morning, Dana. That should be fine, but you could also try the timer-based on/off function I see that model (digital display version) has. You might set it to the 4 hour on/off mode and check to see how the humidity is doing. If it’s rising too high over time I would run it in continuous mode instead.

      The humidity sensors in dehumidifiers and other appliances tend to not be all that accurate so you may find an inexpensive digital humidity gauge to be more helpful for checking it.

      Reply
    • Hi there Brady. No, it won’t really affect standing (liquid) water already there unless the air gets REALLY dry. In severely dry air water evaporates a bit more. But you’ll know when the air is at that point – you can definitely feel it.

      Thanks for visiting!

      Reply
  8. If i live in a very humid area that usually in the fall time is about 69% to 73% during the day, what would be the best level on the dehumidifier to set it at? I ask because i set mine up last night to help my daughters asthma since we are facing a black mold crisis in our rented mobile home and we got the machine to help her breathe better, we set it up just like directed and by morning the bucket was half full of water? that seems like it was to much i would think but then all of a sudden my daughter had a asthma attack so i took her to the ambulance department and they looked at her and said that its possible that the sudden change in humidity could have set her off. if that is the case then what would be the ideal level to set the dehumidifier to in my trailer and do i put it closer to her room or further away?

    Reply
    • Hi Melinda. Gosh, that’s pretty high humidity where you live.

      You normally would still want to set a dehumidifier to 50% or so (under 60%) for both comfort and preventing mold and mildew. The problem is that if you’ve got a source of moisture getting into your home etc it will be a continuous problem. A dehumidifier can help but if there are things like leaks, water/moisture entering, outside air getting in contuously, etc, it may not be able to keep up.

      If you have mold growing that’s often a sign of moisture being present and it will need to be dealt with properly. Mold can be a serious health problem so only using a dehumidifier won’t be enough in some cases.

      My best wishes to you and your daughter!

      Reply

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