PennyPerHourHow much does a dehumidifier cost to run?
A typical compressor dehumidifier uses around 200 watts (5.3p an hour). Desiccant models use more, around 500 watts (13p an hour), but work better in cold rooms.
Electricity 26.32p/kWh, gas 7.97p/kWh (Ofgem cap, 1 October to 31 December 2026). Typical figures.
Dehumidifier running costs
| Appliance | 1 hour | 8 hours | Per month (8h/day) |
|---|---|---|---|
| Mini / Peltier (25W) | 0.7p | 5.3p | £1.58 |
| Compressor, 10–12L (180W) | 4.7p | 38p | £11.37 |
| Compressor, 20L (300W) | 7.9p | 63p | £18.95 |
| Desiccant (500W) | 13p | £1.05 | £31.58 |
Based on 26.32p/kWh, the Ofgem price cap for 1 October to 31 December 2026.
"Per month" assumes 8 hours a day for 30 days. Most dehumidifiers have a humidistat, so once the room reaches your target humidity the compressor or fan cycles off and real costs are often lower.
Compressor or desiccant?
- Compressor dehumidifiers are cheaper to run and remove the most water when the room is warm (roughly 15°C and above). Best for living rooms, bedrooms and general use.
- Desiccant dehumidifiers keep working well in cold spaces like garages, conservatories, boats and unheated bedrooms. They use more power, but that power also gives off a little heat, which helps in cold rooms.
- Mini / Peltier units are cheap but only remove a few hundred millilitres a day. They're fine for a wardrobe, not for a damp room.
Using a dehumidifier to dry laundry
Many dehumidifiers have a laundry mode. In a small closed room, a compressor dehumidifier running for 6 hours costs around 32p, a fraction of a vented tumble dryer at about £1.18 a load. Pairing it with a heated airer speeds things up further.
What size do I need?
- 10–12 litres/day: flats and small homes with mild condensation.
- 20 litres/day: 3–4 bedroom houses, visible damp, or drying laundry indoors.
- Look at the tank size and whether it has a continuous drain hose option so you're not emptying it twice a day.
Work out the cost for your dehumidifier
Change the wattage or hours to match yours.
Default price is the Ofgem cap for 1 October to 31 December 2026. Check your bill for your exact unit rate. Figures exclude standing charges.
What to buy: our picks by need
We recommend types of product based on running costs and features, not specific brands we have tested.
A 10–12 litre compressor model with a humidistat, so it switches off once the room is dry.
See options on Amazon →A desiccant model, which keeps working well below 15°C.
See options on Amazon →A 20 litre model with a laundry mode and a continuous drain option.
See options on Amazon →Shopping for one? Compare current models, prices and wattages before you buy.
Browse dehumidifiers on Amazon →Affiliate link: we may earn a small commission at no extra cost to you.
Thanks for letting us know.
Frequently asked questions
Is it expensive to run a dehumidifier all day?
A 200W compressor model running 24 hours costs about £1.26, and less if the humidistat cycles it off.
What humidity should I set?
Around 50 to 60% is a sensible target for most homes. Lower than that uses more power for little benefit.
Does a dehumidifier help with mould?
It helps by keeping humidity down, which makes it harder for mould to grow. You still need to clean existing mould and fix the cause, such as leaks or poor ventilation.