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Do Dehumidifiers Cool the Air?

By
Updated on December 15, 2022
Written by
Danny Ashton
Danny is the founder of HouseFresh and has been writing about air purifiers and indoor air quality since 2010. He is our lead tester, conducting all the tests we use to evaluate air quality products. That is why you will always see his name attached to our reviews.

Having a dehumidifier offers a wide range of benefits to both your comfort and the protection of your home and possessions. Whether that’s providing relief on a muggy day, removing excess moisture from steam hotspots such as your bathroom and kitchen, or keeping mold and mildew at bay. Owning a dehumidifier often proves to be a shrewd investment. 

However, there is a common opinion that dehumidifiers expel cool air and will make your home colder. For people who live in cold areas, this may be off-putting, while those who live in hotter climates may see a dehumidifier as a solution to keep them cool. But is there any truth to this theory?

Dehumidifiers are one of the top ways of reducing humidity in any space, and can therefore make the atmosphere much more pleasant and healthier. By removing moisture from the air, dehumidifiers can prevent mold and mildew from forming, which can prevent a number of serious health issues, especially for those who have asthma, other respiratory issues, or suffer from allergies. A Washington Post Op Ed showed that keeping a room’s humidity at a level between 40-60% can also help to keep the environment unfriendly to Covid-19.

To get to the bottom of this conundrum once and for all, we’ll explain how a dehumidifier works and what effect that might have on the temperature in your space.  

Can a Dehumidifier Cool the Air?

First of all, let’s address what exactly a dehumidifier does. 

Once your refrigerant (or compressor) dehumidifier is up and running, it will start to draw in gallons of stuffy, humid air. This air is then cooled using refrigerated coils, causing the air to condense and draw out maximum water vapor, known as dew point

The water vapor then collects as condensation on the coils, similar to how the steam in your bathroom turns to condensation when it hits the cold surface of the window. The condensate then in turn filters into an internal reservoir to be recycled or disposed of. 

This then leaves the dry air to pass through a second coil known as a condenser. The condenser will then heat the air slightly until it reaches room temperature, before finally being redistributed by the fan.

So, while the air is cooled in order to extract water vapor, it is reheated back to room temperature before being redistributed into your home. Resulting in no direct temperature change in your space. 

There is also another type of dehumidifier known as a desiccant dehumidifier, and this works a little bit differently. A desiccant dehumidifier uses an absorbent material – such as silica, activated charcoal, or Zeolite – which is formed into a rotor in the dehumidifier. As the moisture passes through the rotor, the water is absorbed by the desiccant and removed from the humid air.

Although both types of dehumidifiers do an excellent job of removing moisture from the air, neither type is actually doing anything to cool the air.

What can often cause confusion is the idea that humidity equals heat. After all, we associate high humidity with warm weather, so it makes sense to assume that decreasing the humidity level will result in a decrease in temperature. 

However, this is certainly not the case. If we consider an air conditioner, these appliances work by pumping the warm air from inside your home and outside, while drawing cool air from outside back into the room, thus reducing the temperature. Because a dehumidifier has no source of ventilation, it can only work with the air already inside the space. With no outlet to expel warm air, the temperature will not drop.

In fact, what we might find instead is that the dehumidifier actually warms the space by a degree or two. Much like other electronic appliances, such as your TV or Fridge, when operating for extended periods they start to produce heat. 

Can a Dehumidifier Make the Air Seem Cooler?

While the temperature may not have actually changed, there’s no denying the air can feel much cooler when running a dehumidifier. As I’m sure we’ve all felt a chill when sitting near our unit, we might now be questioning why this is?

The answer lies in how our bodies react to relative humidity. 

Let’s imagine it’s a very hot day or you’ve just completed some exercise. In either of these scenarios, your body will try to regulate your temperature and cool you down through a process called thermoregulation

The most effective way to cool down the body is to perspire. As your sweat glands release sweat, this liquid then evaporates from your skin, leaving you feeling cooler and more comfortable. However, if you are in an environment with high humidity, the air will already be highly saturated with moisture. Thus making it harder and slower for the sweat to evaporate. This is why it feels muggy, clammy, and ultimately far more uncomfortable on a day with high humidity.

Now let’s consider how your body will react once the dehumidifier has worked its magic. With a lower relative humidity, gone is the heavy, moist air that prevents our sweat from evaporating, and left behind is crisp, dry air that allows our bodies to perspire and cool us down.  

So while the temperature remains the same, the air will feel cooler thanks to your body’s natural cooling processes being able to work more effectively. 

Even if you’ve not been exercising or if the weather is mild, the principles remain the same. As your body is constantly sweating, whether noticeably or not, once the relative humidity has lowered your sweat will evaporate more quickly and perhaps give you a slight chill. Rest assured though, using your dehumidifier isn’t affecting the temperature of your home but simply allowing your body to regulate its temperature.

About the author

Danny Ashton

Danny is the founder of HouseFresh and has been writing about air purifiers and indoor air quality since 2010. He is our lead tester, conducting all the tests we use to evaluate air quality products. That is why you will always see his name attached to our reviews.