Affiliate links: this guide contains Amazon links marked “paid link”. If you buy through them, Humidity Helper may earn a small commission at no extra cost to you. It never changes what we recommend. Read our disclosure.
Quick answer
Compressor dehumidifiers are cheaper to run and best in rooms above about 15°C. Desiccant dehumidifiers keep working in cold rooms, garages and conservatories, are lighter and quieter, and warm the room slightly — but use more electricity. In a well-heated home choose a compressor; in a cold one choose a desiccant.
There are two main types of home dehumidifier sold in the UK, and the right choice depends less on brand or price than on one thing: how warm the room is. Get that right and either type works well. Get it wrong and you’ll end up with a machine that runs all day and barely fills its tank.
How each type works
A compressor dehumidifier works like a small fridge. A fan draws room air over a cold coil; moisture condenses on the coil and drips into the tank; the air is then warmed slightly and blown back out.
A desiccant dehumidifier uses a slowly turning wheel coated in a moisture-absorbing material (usually zeolite). Air passes through the wheel, which soaks up the moisture. A small heater then drives the moisture back out of the wheel, where it condenses and drains into the tank.
Side-by-side comparison
Compressor
Desiccant
Works best
Above about 15°C
From near freezing upwards
Typical power (home models)
150–250W for 10–12L; up to ~500W for 20L
300–650W depending on setting
Effect on room
Barely changes temperature
Warms it by a few degrees
Weight
Usually 10–15kg
Usually 6–8kg
Noise
Fan plus a compressor hum
Fan only
Best for
Heated living spaces, bathrooms, laundry in warm rooms
Compressor dehumidifiers rely on condensing water onto a cold coil. Cool air holds less water, so in a cold room there’s less to condense — and below roughly 10°C the coil can ice up, forcing the unit into defrost cycles. The result is a machine that’s still drawing power but removing a fraction of the water it would in a warm room — the most common reason people find their dehumidifier isn’t collecting water.
That matters because a lot of UK homes are cool for much of the year. Unheated spare rooms, north-facing bedrooms, garages, and houses where the heating is set low to save money can all sit in the 10–16°C range from autumn to spring.
Which should you choose?
Choose a compressor if:
the room is heated to 16°C or more when you’ll use it;
you want the lowest running cost in a warm home;
you’ll use it year-round, including summer;
you need a larger capacity for a whole flat or a serious damp problem.
Choose a desiccant if:
the room is cold — a garage, conservatory, unheated bedroom or holiday let;
you want something lighter to carry upstairs;
you’d welcome a bit of extra warmth in winter;
low noise matters more than the lowest running cost.
Where to start
Best for heated homes
10–12L compressor dehumidifier
10–12L for a room or small flat; 20L for a larger home
Humidity setting and auto shut-off
Laundry mode if you dry clothes indoors
The lower-cost choice in rooms that stay above about 15°C.
How we choose: these are types of product matched to the criteria in this guide, not individually tested models. Check current specifications and reviews before you buy.
What about hybrid models?
A few dehumidifiers combine a compressor and a desiccant wheel, switching between them depending on temperature. They can make sense for a home with a mix of warm and cold rooms, but they cost more and are heavier. For most people, picking the right single type for the room it’ll live in is simpler and cheaper.
In a warm room a compressor model is cheaper — it typically draws 150–250W for a 10–12L unit against 300–650W for a desiccant. In a cold room the gap narrows, because the compressor removes far less water per hour while the desiccant keeps working at full rate, and the desiccant's heat isn't wasted in winter.
Do desiccant dehumidifiers heat the room?
Yes, slightly. The heater that dries the desiccant wheel warms the air coming out, typically raising a closed room by a few degrees. That's welcome in a cold room in winter but unhelpful in a warm room in summer.
Why do compressor dehumidifiers struggle in the cold?
They work by cooling air over a cold coil so moisture condenses. In a cool room there's less moisture to condense and the coil can frost up, so the unit spends time defrosting instead of drying. Below about 15°C performance drops noticeably, and below 10°C many models are inefficient.
Are desiccant dehumidifiers quieter?
Often, because there's no compressor — only a fan. On their lowest settings many are quieter than a compressor model, though on high the fan noise can be similar.
Which type is better for drying clothes?
Both work. A compressor model with laundry mode is cheaper to run in a heated room; a desiccant model's warm airflow can dry washing well in a cold room or unheated utility space.
A plain-English guide to choosing a dehumidifier for a UK home — compressor or desiccant, the features worth paying for, and the marketing claims to ignore.
What a dehumidifier costs to run per hour, day and month at the current UK price cap rate, with a calculator for your own tariff and tips to cut the bill.
