How much does a dehumidifier cost to run?
A compressor dehumidifier costs about 4.13p an hour to run, or 99.2p for a full 24 hours. A desiccant model costs around 8.69p an hour. Most switch off when the room reaches your chosen humidity, so the real daily cost is usually lower.
| Per day | 33.1p |
|---|---|
| Per week | £2.31 |
| Per month | £10.03 |
| October to March | £60.17 |
| Per year | £120.33 |
Cost by power rating
| Power | 1 hour | 8 hours | 24 hours |
|---|---|---|---|
| 150W | 3.95p | 31.6p | 94.8p |
| 200W | 5.26p | 42.1p | £1.26 |
| 250W | 6.58p | 52.6p | £1.58 |
| 330W | 8.69p | 69.5p | £2.08 |
| 450W | 11.8p | 94.8p | £2.84 |
| 600W | 15.8p | £1.26 | £3.79 |
Find the power rating on the label underneath or on the back of the appliance, or in its manual. It is usually written in watts (W) or kilowatts (kW); 1kW is 1,000W.
Compressor or desiccant: which costs less?
There are two types, and they use power very differently.
- Compressor dehumidifiers work like a small fridge, cooling the air so water condenses. Low-energy 10 to 12 litre models draw around 150W to 200W. They are the cheaper choice in a heated home, but they collect less water as the room gets colder.
- Desiccant dehumidifiers pull water out of the air with an absorbent material that is dried by a heater. That heater means they draw more power, typically 300W or more, but they keep working in cold rooms and give off a little warmth.
Power draw also shifts with the room. Meaco's own figures for its 12L Low Energy model are 138W at 10°C and 157W at 20°C, rising to 200W in a warm, very humid room.
The humidistat makes the biggest difference
Most modern dehumidifiers let you set a target humidity, usually between 40% and 60%. Once the room reaches it, the compressor or heater stops and only the fan may keep running. In a home that is only slightly damp, a dehumidifier might work for a fraction of each hour.
That is why the calculator has a "share of time running" setting. It starts at 100%, the most it could cost. If your machine has a humidistat and the room is not very damp, try 40 to 60%. An energy monitor will show the real figure.
Drying laundry with a dehumidifier
Running a dehumidifier in a small closed room with a rack of washing is one of the cheapest ways to dry clothes indoors. Six hours with a 157W compressor model costs 24.8p. It is slower than a tumble dryer and works best with a well-spun load and the door shut. For a heated rack instead, see what a heated clothes airer costs to run.
Ways to cut the cost
- Set the humidistat to around 50 to 60% instead of running on continuous mode.
- Close windows and doors in the room you are drying.
- Use a compressor model in warm, heated rooms and keep a desiccant model for cold spaces.
- Clean or replace the filter regularly so the fan does not have to work harder.
- Run it on a timer at the times the room is dampest, such as after showers or while drying washing.
Common questions
How much does it cost to run a dehumidifier for 24 hours?
A 157W compressor dehumidifier costs 99.2p to run for 24 hours, and a 330W desiccant model £2.08. In practice most models switch off once the room reaches the humidity you set, so a full day usually costs less.
Is a compressor or desiccant dehumidifier cheaper to run?
In a heated home, a compressor model usually uses less power for the same amount of water. Desiccant models draw more power but keep working well in cold rooms, garages and conservatories, where compressor models slow down.
Is it cheaper to dry clothes with a dehumidifier or a tumble dryer?
A dehumidifier is usually much cheaper. Running a 157W compressor model for six hours costs 24.8p, while a tumble dryer typically uses several kWh for one load. It takes longer, though, and works best in a small closed room.
Should I leave my dehumidifier on all the time?
Only if it has a humidistat, which lets you choose a target such as 50 to 60% humidity. It then runs only when needed. Without one, use it for a few hours at a time, or overnight on a timer.
How much electricity does a dehumidifier use?
A small compressor model uses around 0.15 to 0.25 kWh an hour while running, and a desiccant model about 0.3 to 0.6 kWh. At 26.32p per kWh that is roughly 3.95p to 15.8p an hour.