What does a dehumidifier do? Your expert guide

Read on to discover dehumidifier uses, benefits and simple ways to achieve them on a budget too.


Dehumidifier sitting by a sofa inside with a potted houseplant: what does a dehumidifier do?

Key steps

  • Dehumidifiers reduce the humidity in your home by separating the water content from air, and then releasing the drier air back into the room
  • Reduced humidity can help prevent pests, allergies and more.
  • Other ways to lower humidity levels include better ventilation, especially when showering, and trying out a homemade alternative to a dehumidifier

A dehumidifier is a device that reduces humidity levels in the home. Dehumidifier uses include tackling problems with high levels of moisture in the home (such as damp, mould, and pests) and making it generally more comfortable for the residents. Here, we’ll show you how to use a dehumidifier as well as how to achieve the results without buying an expensive dehumidifier. If you are looking to increase the humidity instead, take a look at our guide on how to increase humidity in your home.

To be sure whether you need to use a dehumidifier, and check for ideal room humidity, use a hygrometer to check the humidity levels in your home.

How does a dehumidifier work?

What do dehumidifiers do to reduce humidity at home? The process is fairly simple:

  1. The dehumidifier’s fan mechanism pulls in air from your home
  2. This air is cooled inside the dehumidifier, and the moisture condenses into water
  3. The water is separated off into a different section, and the drier air is lightly re-heated
  4. This air is then released back into the room with much less moisture
  5. The unit will switch off when the room reaches the desired humidity level, or when the water container is full

How to use a dehumidifier:

  1. Different dehumidifiers have different capacities, so factor in the size and humidity of your room before you choose one.
  2. Set up the dehumidifier in the dampest area of the house, like the bathroom or the basement
  3. Consult your chosen dehumidifier’s manual for specific instructions
  4. Set the dehumidifier with your ideal humidity level: this should be between 40% and 60%.
  5. Be aware that the first few cycles that your dehumidifier goes through will be removing more humidity than later cycles: at first, it will be removing excess water that has built up over a certain period of humidity, whereas once it is running regularly it will be collecting lighter amounts of water to maintain an ideal humidity level

What do dehumidifiers do? Dehumidifier benefits

Dehumidifiers are designed to remove excess moisture from the air and help you to reach optimum humidity levels at home. From frizzy hair and sleepless nights to stuffy noses and other allergy problems, excess humidity can be a real problem at home. Excess moisture in the air can also lead to mould and mildew, and create an optimal living environment for pests like silverfish.

Dehumidifiers are often energy-efficient, quiet pieces of equipment which will run in the background as you go about your daily life. When you have one running, dehumidifier benefits include helping laundry to dry faster and food to stay fresh for longer.

Alternatives to getting a dehumidifier:

If you’re looking for a budget-friendly alternative to achieve similar dehumidifier benefits, there are other ways you can reduce the humidity in your home. These include:

  • Opening the windows to increase air flow.
  • Taking shorter showers, in a well-ventilated bathroom.
  • Make your own dehumidifier!
    • Carefully drill small holes in the bottom of a bucket
    • Stack it on top of a second bucket
    • Fill the first bucket with 2kg of rock salt
    • Water from the air will start to collect in the bottom bucket
    • Empty out the bottom bucket every few days.

So now you’ve got the answers to “what does a dehumidifier do?” and you know how to use a dehumidifier to tackle all sorts of humidity problems, you can weigh up the dehumidifier benefits for your home against some more DIY alternatives.

Originally published