Dehumidifiers Buying Guide

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Dehumidifiers Buying Guide

In this article we’ll explain everything you need to know about dehumidifiers and how they can help you maintain a healthy living environment in your home. If you often dry laundry indoors (let's face it, when the weather isn't cooperating and tumble dryer costs are soaring, who doesn't? Read all about that in our Dehumidifier vs Tumble Dryer comparison) or are struggling with damp, humid conditions, then a dehumidifier will be an essential piece of kit!

Keep reading as we demystify the key differences of home dehumidifiers available (ie. compressor and desiccant), as well as important features to consider when making a purchase.

What is a dehumidifier?

A dehumidifier is designed to regulate relative humidity levels by drawing in air, extracting moisture, and releasing the conditioned air back into the environment. The extracted moisture collects in a tank, which can be easily emptied.

Besides keeping a room dry and comfortable, a dehumidifier also contributes to better indoor air quality, making it an excellent investment for anyone who wants to maintain a healthy living or working environment.

Do I need a dehumidifier?

an image of mould on the wall

We often overlook the air quality within our homes, failing to recognise the significant levels of humidity present. Humidity can arise from various sources, including drying laundry and boiling food. Even hot, steamy showers and living in a rainy country can contribute to the issue. As humidity levels increase, condensation may appear on windows or walls. You might also notice musty smells in the air. Dehumidifiers help with effectively managing and reducing excess humidity in your home.

These handy appliances remove moisture from the air, which can help prevent the growth of mould and reduce allergens like dust mites. Did you know that dust mites cannot survive when humidity is below 50%? So, keeping the humidity level low in areas like bedrooms can help prevent them from multiplying, especially useful for areas such as bedrooms.

Not only that, but a dehumidifier can help protect your home and belongings from damage caused by excess humidity. If you notice wallpaper peeling or mould growing on walls or soft furnishings, it's a clear sign that your humidity levels are imbalanced. Investing in a dehumidifier can assist in rectifying this issue and maintaining a healthier environment.

How does a dehumidifier work?

Compressor dehumidifiers

a diagram of how a compressor dehumidifier works

Compressor dehumidifiers, also known as refrigerant dehumidifiers, work by drawing humid air over a refrigerated coil with a fan. The cold coil condenses the moisture in the air, turning it into water that is collected in a tank. This process works the best in warmer climates above 10-15°C.

Desiccant dehumidifiers

a diagram of how a desiccant dehumidifier works

On the other hand, a desiccant dehumidifier uses a desiccant material which is a substance that naturally absorbs moisture. This type of dehumidifier is especially effective in colder climates or lower temperatures under 20°C, such as caravans or cellars, where compressor dehumidifiers are less efficient.

Compressor vs. Desiccant

Compressor dehumidifiers


  • The most common type of dehumidifier used in the home and bedroom
  • Lower running costs
  • Collects higher volume of moisture in warm and humid conditions
  • Higher capacity than equivalent desiccant dehumidifiers


  • Poor performance in environments below 16°C
  • Noisier models than desiccants
  • Heavier models than desiccants which makes them less portable
  • When used in rooms below 16°C, it may take the unit longer to start working fully because it may need to defrost itself

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Desiccant dehumidifiers


  • Operates effectively in conservatories, garages, boats, and caravans
  • Work efficiently in colder environments with temperatures below 10°C
  • Usually quieter models than compressors
  • More consistent performance than compressors


  • Less energy efficient than compressors
  • Do not work in high temperatures above 20°C
  • Higher running costs than compressors

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Which dehumidifier is best for my room?


Compressors are ideal for homes as the refrigerant will work effectively at room temperature.

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Compressor dehumidifiers are ideal for bathrooms, as they effectively operate in warm and humid environments.

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Garage or Basement

Desiccants work best for basements and garages. They can overcome the condensation and damp, and can heat up the air temperature by 12°C.

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Desiccants are perfects for conservatories as they work most efficiently below 15°C. They can be left on their own and will automatically switch off once they reach target humidity.

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What size dehumidifier should I buy?

an image of different sizes of dehumidifiers

The answer hinges on two key factors: the size of your house or room, and the amount of moisture generated by your home environment. The bigger the home or room you want to dehumidify, the more powerful you will need your machine to be.

The tasks you regularly perform at home will influence your choice of dehumidifier. While most dehumidifiers can handle the moisture generated by cooking and showering, you might require a more robust unit if you have a lot of house plants, dry laundry inside regularly, have a cold cellar or live in a wet or humid country.

It's important to remember that 'size' refers to the extraction rate, not the physical dimensions. The extraction rate indicates how much moisture the unit can remove from the air in a day, typically measured in litres. The tank size refers to the amount of water the unit can hold at a time, which is usually less than the extraction rate. A higher extraction rate means the dehumidifier can handle larger or more humid spaces.

For example, a 12L unit means it can extract up to 12 litres of moisture from the air in a day. However, in reality the tank size will probably be around 2.6 litres. Therefore, a 12L unit does not mean it can hold 12 litres of water simultaneously.

To know more about dehumidifier sizes, read our What Size Dehumidifier do I Need article.

Where should I place my dehumidifier?

Create a drier, more comfortable environment by strategically placing your dehumidifier in a central location, such as a landing or hallway. By keeping internal doors open, excess moisture will naturally be drawn towards the dehumidifier, effectively removing it from the air. For targeted dampness problems in specific areas, temporarily relocate the dehumidifier closer to that area for a few weeks.

It's also important to note that some dehumidifiers come with a drainage hose, so if you're planning on using one of these models, make sure you have easy access to the drain.

Features I should look for when buying a dehumidifier:

a blue icon of a laundry mode

Laundry Mode
Laundry Mode is a special function designed to help with indoor laundry drying. When activated, the dehumidifier works at a high capacity to extract excess moisture from the air, accelerating the drying process of wet clothes. Using a dehumidifier instead of a tumble dryer can save you more than £150 a year! Check out more here!

a blue icon of a humidistat

A dehumidifier's humidistat is a vital component that measures and controls humidity levels. Similar to a thermostat, it maintains a desired relative humidity. When humidity exceeds the set level, the dehumidifier turns on, extracting moisture until the desired humidity is reached, promoting optimal indoor air quality and energy efficiency.

a blue icon of a hepa filter

HEPA Filters
A HEPA filter in a dehumidifier efficiently traps tiny particles, including common allergens like dust mites, pollen, pet dander, and mould spores. It works alongside the dehumidifier's moisture reduction function to create a drier, cleaner, and healthier environment.

a blue icon of a noise level

Noise Level
When it comes to dehumidifiers, remember this golden rule: compressor models can be slightly noisier, while desiccant ones tend to be more on the quiet side. Most dehumidifiers operate at a noise level of 36–50dB. For context, most dishwashers operate around 46-60 dB, so they are quieter than a dishwasher.

a blue icon of a smart control

Smart Control
Take control of your environment with WIFI-enabled dehumidifiers! Easily create schedules and monitor your space remotely through a convenient app.

a blue icon of an automatic shut down

Automatic Shut Down
As the tank reaches its maximum capacity, specific models have the intelligence to automatically shut down, preventing any potential overflow.

a blue icon of a daily extraction rate

Daily Extraction Rate
How much water the dehumidifier can extract in 24 hours. The more litres a unit has, the higher its extraction rate is and the more powerful it is.

a blue icon of a tank capacity

Tank Capacity
The bigger it is, the less you must worry about emptying it. Some units have a continuous drainage system, so you don't even have to empty it at all.

Using a dehumidifier in your home can really make a difference to your air quality and any humidity problems you may be having. By effectively drawing out the excess moisture from the environment, it will help you to dry laundry quicker and prevent mould from forming on walls. Whether you're dealing with varying temperatures or specific needs, there's a dehumidifier that's perfect for you.
Don't tolerate the damaging effects of high humidity levels any longer, bring a dehumidifier into your home and experience the noticeable difference it can make.