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 that explains humidity, the right humidity settings for your dehumidifier, and more!
Infographic – Dehumidifier facts and settings
Humidity levels in your home
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:
- Problems like mold, moisture-related odors, and dust mites are controlled
- You feel comfortable
With these 2 goals in mind, let’s continue.
What is humidity?
Relative humidity, as shown in the scale above, directly affects the comfort you feel when exposed to the air both at home and 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!
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 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
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 can be 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.
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
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.
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.
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.
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:
|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.|
Your comments are welcome!
I just bought a dehumidifier I don’t know much about them but I know I have moisture in my bedroom I think my back door is not tight and I’m on the water. It says it has 27 Celsius temperature and 49%. Is that a good reading. It came with a remote control but I don’t know how to use it I can’t even change the battery on it. Oh well maybe you can help me. I am afraid to leave it on all night. So I’m gonna turn it off before I go to sleep tonight.
Hi Theresa! Sorry for the late reply I’ve been traveling this week a bit.
Yes, 49% is good – nearly anywhere around that (say 45-50% or so). I would definitely try to find an owner’s manual on the internet. For dehumidifiers, there’s normally controls to set the humidity level you want to maintain. They often also have a mode but (auto, always running, etc.). Best regards.
So the dehumidify confuses me ugh if I set mine at the lowest percentage level does that mean there will be more or less humidity? At the highest percentage this means?
Hello Tonda. A lower percentage means lower humidity. That also means a dehumidifier will have to run more (and use more electricity overall) than a higher humidity/percentage setting.
A good compromise is a setting that’s not too high (not high enough to be uncomfortable) and not lower than you need. Somewhere around 50% is usually good for most people but whatever works best for you. Best regards.
We set our dehumidifier to 50% and it shuts off once and a while. It still feels a bit humid so I lowered it to 45%. It runs longer between stops however the house now feels much warmer. It seems to crank out a lot of heat. Is this because it’s working too hard? I can keep it at 50% and lower the A/C temp but I was trying to run the A/C less
Hi Mark. It could be because the dehumidifier is running a lot but I’d be surprised if it’s causing the temperature to rise. Not saying it can’t be, just saying it would take a lot of heat to cause the whole house to rise in temperature.
One possibility is that it’s not working as well as it use to which means it would have to run a lot longer. If you’re having to run both the dehumidifier *and* the AC that’s definitely not great for your power bill, as they’re very similar in how they work. Both use a lot of electricity when the compressor is running.
I would consider two things:
1. Picking up an inexpensive temperature/humidity gauge like this one here. They’re super helpful for seeing what’s going on in your home (takes the guesswork out of it).
2. Possibly the dehumidifier lost some refrigerant or has another problem affecting its efficiency.
Air conditioning will also lower the humidity so one possibility is to run it more but that will depend on your home, floor space size, and humidity problem. Hopefully this helps a bit. Best regards!
1 have an old humidifier which the settings low, high or continios dry which setting should i use since i live near the ocean and a couple of my oak boards f;oor started to pop up from the humidity what should i do
Hi Rachel does your owner’s manual go into details about the settings? You would want to use whichever setting will keep humidity a bit below 60% at least. It’s difficult to say without knowing more about the particular model. Ordinarily it should not be the continuous mode, however.
One way to find out if you’re not sue is to use a temperature/humidity gauge so you can see which setting will do that. Best regards.