Where will it run?
What are you seeing?
How warm is it there in winter?
Will you dry washing with it?

10 litres a day

Compressor dehumidifier

    Typical power
    199W
    Per hour
    5.2p
    Per month, 6 hours a day
    £9.55

    Running costs at 26.32p per kWh (Oct to Dec 2026 price cap). This is a rule of thumb, not a survey. How we work it out.

    Models that match

    Dehumidifier size by home, at a glance

    These tables use the same rules as the calculator. Sizes are in litres a day. If you dry washing indoors, go one size up from the figure shown.

    Heated home, 15°C or more: compressor model

    Home Wet windowsDamp patches or musty smellMould or wet walls
    One room 101216
    1 to 2 bed flat 101216
    2 to 3 bed house 121620
    4 bed or more 202525, or two smaller units

    Room often below 15°C, or unheated: desiccant model

    Home Wet windowsDamp patches or musty smellMould or wet walls
    One room 7810
    1 to 2 bed flat 7810
    2 to 3 bed house 81010, or two smaller units
    4 bed or more 1010, or two smaller units10, or two smaller units

    What the size means

    Dehumidifiers are sold by how many litres of water they can pull out of the air in a day. That figure is measured in the maker's test conditions, usually warmer and more humid than a UK home in winter, so in a normal home a 12 litre model will collect a lot less than 12 litres. That is why the calculator starts from your home's size and steps up for damp, mould and laundry rather than trying to match litres to the water you think you have.

    Buying a size up is rarely wasted. A bigger unit reaches a dry room sooner, then its humidistat switches it off, so it doesn't cost much more to run than a smaller one working flat out.

    Compressor or desiccant

    Compressor dehumidifiers work like a small fridge: air passes over a cold coil and the water condenses out. They use little power, but the coil struggles once the room is below about 15°C. Desiccant models soak water up with an absorbent wheel and use a heater to dry it out, so they keep working in the cold but use more electricity, and they warm the room slightly as they go.

    Compressor vs desiccant in more detail.