Quick Answer: What Does a Dehumidifier Cost to Run?
- 4.6p to 9.4p an hour for the models we sell, at the current UK price cap.
- £5.48 to £11.28 a month if you run it four hours a day, every day.
- Far cheaper than a tumble dryer. Four hours on laundry mode is 18–38p; a condenser dryer cycle is 78p–£1.31.
- Your real bill will be lower than the table suggests — the humidistat stops the machine once the room is dry.
All figures use 26.11p per kWh, the electricity unit rate under the Ofgem energy price cap for 1 July to 30 September 2026 (including VAT). The cap is reviewed quarterly — the method below lets you recalculate with whatever rate you are actually paying.
How to work it out yourself
The sum is short, and it works for any appliance in the house:
(Watts ÷ 1,000) × hours × unit rate = cost
So a 245W dehumidifier running for four hours uses 0.245 × 4 = 0.98 kWh. At 26.11p that is about 26p. Note that the wattage on the label is the maximum draw, not what the machine averages over a session — more on that below.
What each of our dehumidifiers actually costs
These are the real rated power figures from the manufacturers' own specification sheets, not estimates.
| Model | Power | Per hour | 4 hrs | Per month (4 hrs × 30) |
|---|---|---|---|---|
| Mitsubishi MJ-E 10L/day | 175W | 4.6p | £0.18 | £5.48 |
| Panasonic 2-in-1 12.6L/day | 226W | 5.9p | £0.24 | £7.08 |
| Sharp DW-RN23A 13L/day | 230W | 6.0p | £0.24 | £7.21 |
| Mitsubishi BIKUKAN 14.2L/day | 230W | 6.0p | £0.24 | £7.21 |
| Mitsubishi MJ-E 13L/day | 245W | 6.4p | £0.26 | £7.68 |
| Panasonic 2-in-1 17.3L/day | 334W | 8.7p | £0.35 | £10.46 |
| Panasonic Inverter 23.6L/day | 357W | 9.3p | £0.37 | £11.19 |
| Mitsubishi MJ-EV 23L/day | 360W | 9.4p | £0.38 | £11.28 |
Dehumidifier versus tumble dryer
For a lot of UK households the honest comparison is not "dehumidifier or nothing" — it is "dehumidifier or tumble dryer". If you are drying washing indoors anyway, this is where the running cost argument is won.
Cost per drying session at 26.11p/kWh. Tumble dryer consumption figures are typical UK ranges; dehumidifier figures use the actual rated power of the models we sell.
The dehumidifier also has a second job. It is protecting the room from the condensation that indoor drying otherwise causes — which is a cost you only notice when you are repainting a mouldy window reveal. We cover that in Does a dehumidifier help with mould?
If wet windows are your main problem, start with how to stop condensation on windows — four of the six steps there are free.
Why your real bill will be lower than the table
Three things pull the actual figure down:
- The humidistat. Set a target of around 50% and the machine cycles off once the room reaches it. It is not running for every one of those four hours.
- Test conditions are warmer than a British house. Manufacturers rate dehumidifiers at 27°C/60% or 30°C/80% humidity. A UK living room in February is nowhere near that, and a compressor draws less power in cooler air.
- Inverter and hybrid models modulate. Rather than running flat out or not at all, they throttle back as the room approaches target.
Set a humidity target rather than simply switching the unit on — it is the single biggest thing you can do to keep running costs down.
Five ways to cut the cost
- Set 50%, not "on". Running to a target rather than continuously is the biggest single saving.
- Close the door. Drying one room works. Trying to dry the whole house through open doorways means the machine never reaches target and never switches off.
- Clean the filter. A clogged filter makes the fan work harder for less airflow. It takes two minutes.
- Buy the right capacity. An undersized unit running all day costs more than a larger one that reaches target in two hours and stops.
- Run it while the heating is on. Dehumidifiers work more efficiently in warmer air, so pairing the two is cheaper than running the dehumidifier in a cold room.
Will a dehumidifier push up my heating bill?
No — if anything the opposite. Dry air heats up faster and feels warmer at the same thermostat setting, because you lose less body heat to evaporation. A compressor dehumidifier also releases its waste heat back into the room rather than venting it outside, so the energy it uses is not entirely lost. Plenty of households find they are comfortable a degree lower on the thermostat once the damp is under control.
Which is cheapest to run?
Comparing brands and capacities in more detail? See our Best Japanese Dehumidifiers UK guide, or browse the full range of Japanese dehumidifiers.
Pennies an hour, not pounds
Genuine Japanese dehumidifiers — Mitsubishi, Panasonic & Sharp. Authentic 220–240V with a fitted UK plug and 3-year HappyCare support.
Shop dehumidifiersFrequently asked questions
Q: How many hours a day should I run a dehumidifier?
A: There is no fixed number — set a humidity target instead. Every model here has a humidistat, so you set it to around 50% and the unit runs only until the room reaches that level, then cycles off. In a damp British winter that might work out at four to eight hours of actual running; in summer it may be under an hour.
Q: Is it expensive to leave a dehumidifier on overnight?
A: No, and it is cheaper than most people assume. At 26.11p/kWh, an eight-hour overnight run costs between 37p and 75p depending on the model, and less again in practice because the compressor stops once the target humidity is reached. That is roughly the same as leaving a 100W television on for the same period.
Q: Is a dehumidifier cheaper than a tumble dryer?
A: Yes, usually by a wide margin. A condenser tumble dryer cycle uses roughly 3–5 kWh, which is 78p to £1.31 at current prices. Four hours of a dehumidifier on laundry mode is 18p to 38p. A heat-pump dryer sits in between at roughly 31p to 52p a cycle.
Q: Do dehumidifiers use a lot of electricity?
A: No. The models we sell draw between 175W and 440W depending on size and conditions — less than a typical hairdryer, and a small fraction of a kettle or an oven. The running cost comes from how long they are on, not from a high draw.
Q: Which type is cheapest to run — compressor or hybrid?
A: A compressor model is the cheaper choice in a normally heated home, because it works with the warmth already in the room. Hybrid and inverter models use more power but keep working properly in cold spaces such as an unheated garage or conservatory, where a plain compressor would struggle.
Q: These figures will change when the price cap changes — how do I recalculate?
A: Take the model's wattage, divide by 1,000 to get kilowatts, then multiply by the hours you run it and by your own unit rate in pounds. A 245W unit running four hours is 0.245 × 4 = 0.98 kWh, so at 26.11p that is about 26p.