Desiccant vs compressor dehumidifier: Is your house too cold for your dehumidifier?

woman in cold bedroom
(Image credit: Getty Images)

Not all dehumidifiers are designed for the same conditions so if you have found that yours isn't working as it should you might have selected the wrong model for your home. 

While some dehumidifiers function perfectly well in cold houses, this is not a given and this is where it really pays to do your research when selecting the right kind of appliance for your needs. The best dehumidifier for you will be perfectly suited to the conditions within the space you will be using it, as well falling within your budget and fulfilling any particular requirements you have — such as a laundry drying function. 

Here, with the help of the experts, we look at desiccant vs compressor dehumidifiers and which is the best dehumidifier for cold rooms. 

Why don't compressor dehumidifiers work in the cold?

There are two main types of dehumidifier — compressor and desiccant. First of all it is useful to ask how do dehumidifiers work?

In short, dehumidifiers help achieve the desired humidity levels in the room they are located, but the way in which they do this and the conditions they work best in varies. 

"A dehumidifier removes moisture from the air — excess moisture that you do not want to condense and hang around your home," explains Chris Michael, Meaco’s Managing Director. "It helps to ease damp problems, gives you healthier air to breath and can even make your energy use more efficient.

"Compressor units run on a refrigerant," continues Chris. "So, just like a fridge, if they get too cold, they go into defrost. While this is not a bad thing, and the units will do this cycle from time to time, you don’t want to spend your money on a machine that will defrost more than it will dehumidify. If it is going to be used in a space where the temperature goes below 15 degrees centigrade, a desiccant variety will be better."

white dehumidifier in utility room with wet washing hanging

In cold rooms, such as garages and utility rooms, desiccant dehumidifiers are often the best choice.  (Image credit: Dimplex/Quiet Mark (UK))

What is the best type of dehumidifier for cold rooms?

"A desiccant dehumidifier is recommended in any environment where the room temperature will rarely go above 10°C," says Chris Michael. "This means they will suit a cold conservatory or utility room, or perhaps a garage, boat or caravan.

"The air generated by a desiccant dehumidifier is 10-12°C warmer than room temperature, so this extra heat can be a welcome way to keep a room a little cosier," continues Chris. "This isn’t possible with a compressor dehumidifier. Naturally creating this extra warmth has a cost so it’s recommended weighing up whether this benefit offers you the best value for money for your needs."

Is a compressor or desiccant dehumidifier best in a cool room?

Of course rooms in houses are not always nice and warm or freezing cold — sometimes they fall somewhere in the middle and this is where choosing the right dehumidifier can be tricky.

If the room that you want control the humidity levels in generally sits somewhere between 10-16°C you have a couple of choices. 

"A large compressor or desiccant dehumidifier – 20 or 25 litres – has a larger cooling system internally and will much more efficient in cooler rooms," says Chris. "A smaller 10 or 12 litre machine will achieve little at these temperatures and offer less value for money. 

"Unlike desiccant dehumidifiers, compressor dehumidifiers only change the temperature of the air by 1-2°C as it passes through them. As there is no real effect on the room, they are cheaper to run. Some consumers are choosing to use a desiccant dehumidifier in these situations as the bit of extra warmth from the dehumidifier is just enough to avoid turning the heating on, saving more money."

modern dehumidifier in home office

In warmer rooms, a compressor dehumidifier is your best option — they also tend to be cheaper to run than desiccant.  (Image credit: Duux)

What size compressor dehumidifier do I need?

If you are looking for a dehumidifier for a warm room that frequently suffers from condensation as temperatures fall outside, you will need to ensure you choose the right size model for your needs — or you will simply be wasting your money. 

"Any compressor dehumidifier will perform well in temperatures of 16˚ or more. The warmer the room, the more moisture they will remove from the air," says Chris. "One 10 or 12 litre machine will dry a room, or work well if you are living in a flat or apartment. A three-bedroom house or larger property would require a 20 or 25 litre machine, or work well if you need to dry washing frequently."

Chris Michael
Chris Michael

Chris Michael, Meaco's founder, has worked within the air treatment industry for over 30 years.

Natasha Brinsmead

Natasha is Homebuilding & Renovating’s Associate Content Editor and has been a member of the team for over two decades. An experienced journalist and renovation expert, she has written for a number of homes titles. Over the years Natasha has renovated and carried out a side extension to a Victorian terrace. She is currently living in the rural Edwardian cottage she renovated and extended on a largely DIY basis, living on site for the duration of the project. She is now looking for her next project — something which is proving far harder than she thought it would be.