What Does a Dehumidifier Do?

High humidity can often be problematic, both for your health and your home. It can be caused by poor ventilation, an untreated water leak, or simply the weather conditions.

There are several steps you can take to resolve high humidity levels indoors, and adding a dehumidifier is certainly one of the simplest steps you can take. In this article, we’ll explain what a dehumidifier does, how they work, the different types of methods they use to remove humidity from the air, what the benefits are, and how to choose the right one for your space.

How Does a Dehumidifier Work?

The goal of a dehumidifier is to draw the moisture from the air, in order to reduce the humidity of space and prevent mold growth and other similar problems. Before we go into more detail on how they do it, we should take a moment to mention the two methods dehumidifiers use. Depending on the method, dehumidifiers can either be refrigerant (compressor) and desiccant.

Refrigerant Dehumidifiers

Refrigerant dehumidifiers work based on a similar principle to air conditioners. A fan draws the air into the dehumidifier, which then cools down and condenses the moisture in the air into water as it passes over the cooled-down coils. This happens due to the temperature difference between the air and coils. One water droplet at the time, condensed moisture falls into a storage tank or removable bucket. Dry air is then reheated and released into the room.

Keep in mind that the ideal relative humidity for indoor conditions is between 30% and 50%, and these devices should be able to achieve that range. We should also note that most dehumidifiers will automatically shut down if the water storage container is full. The same happens when the target humidity level is reached.

This type of dehumidifier requires the air in the room to be warmer than the coils, which implies that refrigerant dehumidifiers perform better in a heated room compared to an unheated one. In case of low room temperatures, the moisture collected on the coils might freeze. That’s why dehumidifiers come with defrost features included. Remember that a dehumidifier can’t perform both these actions at the same time, so it has to defrost the coils before it can continue collecting moisture from the air.

Desiccant Dehumidifiers

Desiccant dehumidifiers work using highly adsorbent materials. Those sorption materials draw moisture and so dry the air. They’re located in a slowly turning rotor, which continuously rotates between two different air streams, which are flowing in opposite directions. The moisture is then collected in sorption material and heated using a warm air stream.

Since this entire process works based on sorption, it comes clear that room temperatures don’t make much of an impact on the desiccant dehumidifiers. That’s why they’re always a better solution for your garage, basement or attic, and other colder places in your home.

Warming the adsorbent material in a desiccant dehumidifier can require more energy than cooling the coils in a refrigerant one. That also implies that more heat might be emitted back into the air, so keep this in mind since heating up an already heated room might not be ideal.

When to Use a Dehumidifier?

In this section, we’ll take time to discuss some of the signs that suggest you should purchase a dehumidifier.

  • If wooden items in your home, such as windowsills or floors, feels soft to the touch, then it’s rotting from high humidity.
  • In case you notice condensation on your windows often.
  • If your home was flooded, or you presume that it might be flooded before you moved in due to the water stains on floors and furniture. In such cases, the best choice is to hire a professional to handle the problem.
  • If your place smells moldy or musty.
  • In case you notice mold or mildew growth. Both usually start as tiny dark spots, and they can be found on the ceilings and walls as well as on other items in your home.

Dehumidifiers can be used all year long if there is excessive moisture present. For instance, during the summer, the indoor air often becomes moist and sticky, but if opening a window doesn’t improve things, then the best solution is to use a dehumidifier.

How to Use a Dehumidifier?

Although dehumidifiers are simple and easy to use, I’d still like to take a moment to mention some of the tips which will help you use it in a more efficient way.

  • Before switching your dehumidifier on, you should vacuum the room, to avoid spreading dust all over the room and clogging up the filter. This step is crucial for people sensitive to allergens.
  • Make sure your windows and doors are shut before you turn your dehumidifier on. Otherwise, it will spend much more time and energy attempting to dehumidify all of the air in the world.
  • Although most of us would like to place a dehumidifier where it doesn’t attract too much attention, it’s important to note that its position in the room is crucial for its effectiveness. Remember that your dehumidifier should be faced away from walls, curtains, and furniture, so the air stream can flow freely.
  • Removing water from the water tank each time you turn your dehumidifier off, is a good idea. In case you want to pack and store your dehumidifier this step is a must. You should also wipe the tank using a cloth to prevent mildew and mold growth in the stale water.
  • Clean the air filter as often as possible, to prevent it from blocking. Vacuum cleaners should do a good enough job there, but in case your air filter is very dirty, our advice would be to wash it or replace it. Make sure you consult the user manual before doing so because you don’t want to damage your filter while washing it.
  • In case you need a dehumidifier for the space where you keep anything of value, such as photo albums, baseball cards, or guitars, you may need to do additional research into the target humidity range to protect those items.

How to Pick the Best Dehumidifier for Your Space?

There’s plenty of different dehumidifiers available on the market, but how do you choose the right one? Now that we know what a dehumidifier is and how it works we can focus on the factors that determine what kind of a dehumidifier you need.

Generally, humidifiers all function in the same way regardless of the room where they’re placed. Anyway, the size of the room, existing conditions in it, and a humidifier’s (dis)ability to work on temperatures below 65 degrees should have a crucial role when deciding which dehumidifier to buy.

Another factor to consider here is the capacity of the dehumidifier, which is expressed through the number of pints of water that it extracts over a 24-hour run.

What Size of Dehumidifier Is the Right for You?

Based on the Energy Star’s guide, here’s an overview of which humidifier capacity best suits what size of the room and the conditions in it:

Conditions before Dehumidification Area in Square Meters

500                               1500                            2500

Moderately Dump 10 pints 18 pints 26 pints
Very Dump 12 pints 22 pints 32 pints
Wet 14 pints 26 pints 38 pints
Extremely Wet 16 pints 30 pints 44 pints

What Are the Health Benefits of Dehumidifiers?

Unpleasant smell and sticky air aren’t the only downsides that go along with high humidity levels. Your health might be affected by it too, so let’s talk about the ways in which dehumidifiers can improve your health.

To start with, dehumidifiers can help reduce allergy symptoms caused by allergy triggers such as dust mites, mold, animal dander, and pollen. Those symptoms include sneezing, itching, eye irritation, wheezing, and even chest pain. Keep in mind that dust mites thrive in spaces with humidity levels at around 65%, and that level can easily be resolved by a dehumidifier.

Although there’s no scientific evidence that dehumidifiers can help control asthma, one thing is for sure: cooler, dry air makes breathing easier on the lungs. This is significant for people suffering from asthma since humid air makes breathing more difficult for them.

Using a dehumidifier removes mold and dust, and by doing so it also resolves problems such as spiders, cockroaches, and silverfish. Reducing the humidity levels can be beneficial to people who suffer from the chronic obstructive pulmonary disease (COPD).

For those who live in areas with naturally high humidity levels, using a dehumidifier can help reduce the room temperature, and cut down the air conditioner use.

Final Words

This concludes our post on what a dehumidifier does. We hope you like the article and find it helpful. As always, if you have any questions, or need more detail on some of the points, you’re more than welcome to write a comment below. We’ll be happy to provide you with an answer quickly.