What Humidity Should I Set My Dehumidifier To?

If you weren’t already aware, humidity can be a huge factor that really impacts your home’s comfort and can contribute to a lot of problems if not dealt with. It’s not just about feeling like the air is too dry or too humid. There’s a lot more to know. 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?” here’s what you need to know.

Home air quality is very important to me and I believe everyone deserves to enjoy great comfort at home. I wrote this post to tell you the settings you should use for your dehumidifier and help you learn a bit more along the way.


To simplify things, I’ve divided this post into a few sections. You can click to jump to any part if you’re in a hurry. However, I strongly encourage you to read through my entire post in order to really understand humidity and dehumidifiers better.


Infographic – Dehumidifier facts and settings

Infographic - what humidity should I set my dehumidifier to

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Humidity levels in your home

Image of a woman sweating and cooling with a fan due to high humidityHigh 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 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 minimal operating temperature of your humidifier. Be sure you don’t attempt to operate it at a lower temperature than it’s rated for.

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Basement dehumidifier settings

Dehumidifier in basement image
Basement humidifiers 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 like 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 afterwards.

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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, the Frigidaire FAD504DWD dehumidifier.

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 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 you 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.

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Dehumidifier settings table

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

Type/Location Dehumidifier Settings Notes
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.

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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!


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