How much does a dehumidifier cost to run?
A typical dehumidifier costs about 5.2p an hour — and paired with a clothes airer, it can dry a load of washing for roughly 29p, compared with about £1.14 in a tumble dryer.
Dehumidifiers are one of the cheapest appliances to run in the house — they draw about the same power as a couple of old light bulbs. That makes them a quiet favourite for drying washing indoors without the tumble dryer bill.
Drying a load, side by side
| Drying method | Time | Per load |
|---|---|---|
| Dehumidifier + airer | about 5–6 hours | ~29p |
| Heated clothes airer | about 8 hours | ~62p |
| Standard tumble dryer | about 2 hours | ~£1.14 |
These are illustrative examples, not guaranteed times. Clothes, spin speed, load size and room conditions all affect drying. Check your appliance's energy label for its own figures.
How laundry mode helps
Hang your washing on an airer in a small room, shut the door and run the dehumidifier on laundry mode. It pulls the moisture straight out of the clothes, so they dry faster than on an airer alone — and the room stays free of damp and condensation.
At 3 loads a week, drying this way instead of in a standard tumble dryer saves roughly £134 a year — but only if you get the technique right.
The honest bit: there's a technique to it
Lots of people buy a dehumidifier, leave it on all night, and wake up to clothes that still feel damp. Get it wrong and you'll end up running it for hours, then finishing the load in a tumble dryer anyway — paying for both. These are the usual reasons it lets people down:
- The room is too cold. Most dehumidifiers struggle in a chilly room in winter and pull out far less water. Cold homes suit a "desiccant" type, which works in the cold but uses more power.
- The tank fills up overnight. A load of washing holds a couple of litres of water. A small tank fills by the early hours, the machine switches off, and the clothes sit there damp.
- The air isn't blowing on the clothes. It dries the air, not the fabric. Point it straight at the airer.
- The room is too big or the door is open. It ends up drying the whole house instead of your washing.
How to make it work
- Use a small room with the door and window shut. A box room or bathroom works best.
- Take the chill off the room first. Warm air lets go of moisture much faster than cold air.
- Point the air at the clothes. Aim it into the airer, not at the wall.
- Space the clothes out. Leave gaps so air can move between items.
- Spin faster first. An extra spin in the washing machine removes water the dehumidifier would otherwise have to pull out.
- Buy a big enough one. A larger unit with a bigger tank (or a hose to drain it) keeps going all night.
Not a fit for every home. If you don't have a small room you can close off, or your house runs cold in winter, a heated airer with a cover or a heat pump dryer will be more reliable — and cheaper than drying twice.
All prices calculated at 26p per kWh
See how drying compares with cooking, heating and boiling water — all priced the same way.