Running Costs
How Much Does a Dehumidifier Cost to Run in the UK?
Updated June 2026
The most common question before buying a dehumidifier: how much will it add to my electricity bill? The honest answer: much less than you think. A modern compressor dehumidifier costs 3–7p per hour to run. Over a month of typical use, that is £5–£15 — less than a Netflix subscription. Here are the exact numbers for every type, plus tips to reduce the cost further.
Struggling with gas bills? See our 10 cheap fixes to reduce your heating costs— most under £30 and paying for themselves within weeks.
Quick answer
A 12L compressor dehumidifier costs approximately 4–7p per hour (£5–£12 per month with typical use of 6 hours/day). A desiccant dehumidifier costs 8–15p per hour. Running a dehumidifier is far cheaper than repairing mould damage, replacing rotted window frames, or treating damp-related health problems.
The simple formula
Running cost per hour
Wattage (kW) × Electricity rate (p/kWh)
Example: 200W compressor ÷ 1000 = 0.2kW × 24.5p = 4.9p per hour
UK average electricity rate in 2026 is approximately 24.5p per kWh. Your rate may differ — check your energy bill.
Running costs by dehumidifier type
| Dehumidifier Type | Wattage | Cost/Hour | Cost/Day (6hrs) | Cost/Month | Cost/6 Months |
|---|---|---|---|---|---|
| Small compressor (10L) | 150–200W | 3.7–4.9p | 22–29p | £6.60–£8.70 | £40–£52 |
| Medium compressor (12L) | 200–250W | 4.9–6.1p | 29–37p | £8.70–£11.10 | £52–£67 |
| Large compressor (20L) | 300–450W | 7.4–11p | 44–66p | £13–£20 | £79–£119 |
| Desiccant (8-10L) | 350–600W | 8.6–14.7p | 52–88p | £15–£27 | £93–£159 |
| Mini Peltier (500ml) | 40–75W | 1–1.8p | 6–11p | £1.80–£3.30 | £11–£20 |
These are maximum costs. In practice, dehumidifiers with built-in humidistats cycle on and off — they don't run at full power constantly. Real-world costs are typically 30–50% less than the maximum.
Compressor vs desiccant: which costs less?
Compressor dehumidifiers use significantly less electricity — typically half the wattage of a desiccant for the same extraction rate. They work by cooling air to condense moisture, which is efficient in warm rooms.
BUT desiccant dehumidifiers work better in cold rooms (below 15°C) where compressors become less efficient. The refrigerant in a compressor dehumidifier struggles to cool air that's already cold, so extraction rates drop dramatically in unheated spaces.
In a heated bedroom, a compressor wins on running cost. In an unheated spare room or garage in winter, a desiccant may extract more moisture per penny despite the higher wattage. For a full comparison of the best models, see our best dehumidifiers guide.
Real-world running costs from our recommended dehumidifiers
MeacoDry Arete Two 12L
~4p/hourOur #1 recommended dehumidifier. One of the most energy-efficient on the market.
Pro Breeze 12L Which? Best Buy
~6p/hourBest budget compressor with smart app control.
EcoAir DD1 Classic MK6 (Desiccant)
~10p/hourBest for cold rooms below 15°C where compressors struggle.
MeacoDry Arete One 6L
~4p/hour2-in-1 dehumidifier + HEPA air purifier. Most versatile option.
5 ways to reduce your dehumidifier running cost
- 1
Use the built-in humidistat
Set target to 50–55% RH. The dehumidifier cycles off when reached instead of running constantly. This alone cuts costs 30–50%.
- 2
Run it in the right room at the right time
Close doors and windows in the room you're dehumidifying. Running it in an open-plan space wastes energy.
- 3
Use laundry mode wisely
Only use laundry mode when drying clothes. It runs at maximum power. Switch back to normal mode after.
- 4
Keep the filter clean
A clogged filter makes the dehumidifier work harder. Clean it every 2 weeks.
- 5
Fix the source of moisture
A dehumidifier treats the symptom. Fix leaks, improve ventilation, and draught-proof to reduce how hard the dehumidifier needs to work.
Dehumidifier vs the cost of NOT having one
- Running a dehumidifier 6hrs/day for 6 months£50–£70
- Replacing a mould-damaged mattress£200–£500
- Professional mould treatment£300–£1,000
- Replacing rotted window frames£500–£2,000+
- NHS estimates: damp/mould health impacts (UK total)£1.4 billion/year
A £10/month electricity cost is insurance against hundreds or thousands in damage.
Not sure if you need a dehumidifier? Check your humidity first with a £10 hygrometer before investing in a larger unit.
Frequently asked questions
Should I leave my dehumidifier on all day?
No. 4–8 hours per day is enough for most homes. Use the humidistat to auto-stop at 50-55% RH. Running constantly wastes electricity and can make the air uncomfortably dry.
Is it cheaper to run a dehumidifier or open a window?
Opening a window is free but impractical in winter and doesn't work when humidity outside is also high. In summer, ventilate. In winter, a dehumidifier is more effective and often cheaper than the heat loss from open windows.
Do dehumidifiers make the room warmer?
Compressor dehumidifiers release a small amount of waste heat — typically 1–2°C warmer air than the room. Desiccant dehumidifiers release more heat because their heating element runs constantly. Neither replaces a proper heater.
Which is cheaper to run: a compressor or desiccant dehumidifier?
Compressors are cheaper in heated rooms (15°C+). They use half the electricity for the same extraction rate. Desiccants cost more per hour but work better in cold unheated rooms (under 15°C) where compressors become inefficient.
Does a dehumidifier use a lot of electricity?
No. A typical 12L compressor uses 200-250W — about the same as a large TV or desktop computer. At 24.5p/kWh, that's 4.9–6.1p per hour. With a humidistat cycling it on/off, real costs are typically 30-50% lower.