How much does a dehumidifier cost to run in the UK?

With electricity still expensive, it’s fair to ask whether a dehumidifier will push your bill up. Most home dehumidifiers use far less power than a heater, kettle or tumble dryer — and with a couple of simple settings they cost a lot less than their headline wattage suggests.

The quick formula

Cost = watts ÷ 1,000 × hours × your unit rate

So a 200W dehumidifier running for 8 hours at 26.32p per kWh uses 1.6kWh and costs about 42p. Use the calculator below with your own numbers.

Running cost calculator

Find the wattage on the label or in the manual — use the figure for the mode you’ll actually run.

Power (watts)Hours per dayUnit rate (p/kWh)

Per day

42.1p

Per week

£2.95

Per month

£12.63

Estimates assume the dehumidifier draws its rated power the whole time. Most compressor models cycle off once the room reaches the target humidity, so real costs are usually lower.

Typical running costs by type

Estimates for an 8-hour session at 26.32p per kWh, assuming the unit runs continuously at its rated power:

Type	Typical power	Cost per hour	Cost per 8 hours
Mini (Peltier) dehumidifier	25–70W	under 2p	5–15p
10–12L compressor	150–250W	4–7p	32–53p
20L compressor	300–500W	8–13p	63p–£1.05
Desiccant	300–650W	8–17p	63p–£1.37

A few things to bear in mind:

• Mini dehumidifiers are cheap to run because they do very little. They remove a few hundred millilitres a day at most — fine for a cupboard, not for a room.
• Compressor models are cheapest per litre in warm rooms. In cold rooms their efficiency drops sharply. See desiccant vs compressor.
• Desiccant heat isn’t wasted in winter. If it means you can leave a radiator off in a cold room, the overall cost can be similar.
• Bigger isn’t always dearer to run. A 20L unit uses more power per hour, but reaches your target humidity sooner and then cycles off. Our capacity comparison explains the trade-off.

What it costs over a month

For a typical 200W compressor model at 26.32p per kWh:

Use	Daily energy	Per month (30 days)
4 hours a day	0.8kWh	about £6.32
8 hours a day	1.6kWh	about £12.63
24 hours, continuous	4.8kWh	about £37.90

In reality almost nobody pays the 24-hour figure. Set to a target of around 50%, most compressor models cycle off for long periods once the room is dry.

Seven ways to cut the cost

1. Use the humidity setting. Set it to around 50% rather than “continuous”. Our guide to the ideal humidity in a UK home explains why lower isn’t better.
2. Close the door of the room you’re drying, so you’re not drying the whole house. More placement tips in how to use a dehumidifier.
3. Match the type to the room temperature — a compressor in a cold room wastes electricity.
4. Clean the filter every couple of weeks; a clogged filter makes the fan work harder.
5. Tackle the sources first — lids on pans, the extractor fan on, washing in one room with the door closed. Less moisture means less running time.
6. Use laundry mode for washing rather than drying clothes on radiators, which pushes moisture into the house and makes the boiler work harder. See using a dehumidifier to dry clothes.
7. Measure it. A smart plug with energy monitoring on Amazon (opens in a new tab) (paid link) shows exactly what your unit costs per day, which is often less than you’d expect.

Is it cheaper than the alternatives?

For drying clothes, a dehumidifier is usually cheaper per load than a vented or condenser tumble dryer, similar to a heat pump dryer, and it dries the room at the same time — the full numbers are in our dehumidifier vs tumble dryer vs heated airer comparison. Compared with leaving windows open in winter, it often works out cheaper too, because you’re not losing heat the boiler has already paid for.

Still deciding whether you need one? Start with signs you need a dehumidifier, or use the size calculator to see what size suits your home.