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Quick answer
For most UK bedrooms, a 10–12 litre compressor dehumidifier with a proper sleep mode (dimmed lights, low fan, around 35–40 dB) is the best all-rounder. If the room is cold — below about 15°C overnight — a desiccant model works better and adds a little gentle warmth.
Bedrooms are where a lot of UK damp problems show up first. You breathe out moisture all night, the door is usually shut, the heating is often turned down, and by morning the windows are running with water. Leave that for a winter and black mould starts creeping into the corners, behind the wardrobe and along the window seals.
A dehumidifier can fix that, but a bedroom asks more of one than a hallway or utility room does. It has to be quiet enough to live with, small enough to fit, and effective in a room that might drop to 14°C overnight. This guide covers exactly that.
What makes a dehumidifier good for a bedroom
Extraction rate gets all the attention on product listings, but for a bedroom these matter more:
Noise. Look for a quoted sleep or quiet mode of around 35–40 dB — roughly a quiet library. Normal modes are usually 40–50 dB, which many people find too much for sleep.
A real sleep mode. That means a lower fan speed and dimmed or switched-off display lights. A bright blue LED is surprisingly annoying at 3am.
A humidistat. A setting you can fix at 50% so the unit cycles off when the room is dry enough, rather than running flat out all night.
The right type for the temperature. Compressor models lose a lot of efficiency in cold rooms; desiccant models don’t. More on this below.
A sensible tank. Around 2 litres or more means you won’t wake up to a full-tank alarm.
Auto-restart. If there’s a power cut, it carries on with your settings.
Compressor or desiccant for a bedroom?
Both can work well. The choice comes down mainly to how warm the room is. For the full comparison, see our guide to desiccant vs compressor dehumidifiers.
Compressor
Desiccant
Best room temperature
Above about 15°C
Works well even when cold
Running cost
Lower in warm rooms
Higher, but steady
Noise
Low hum from the compressor; varies by model
Fan noise only; often quieter in sleep mode
Effect on room
Barely changes temperature
Warms the room by a few degrees
Weight
Heavier
Lighter and easier to move
Summer use
Better — doesn’t add heat
Can make a warm room uncomfortable
Choose a compressor if your bedroom is heated to a normal temperature in winter, or you want the lowest running cost.
Choose a desiccant if the room is cold, if it’s a box room or a north-facing room, or if you’d welcome a bit of extra warmth in winter.
These are the types of dehumidifier we’d shortlist, with what to look for in each. We link to Amazon’s current range rather than a single model, so you can compare prices and the latest versions yourself.
Dehumidifiers that suit bedrooms
Best for most bedrooms
Quiet 10–12L compressor with sleep mode
Sleep mode quoted at around 35–40 dB
Display that dims or turns off
Adjustable humidity setting (aim for 50%)
Tank of 2 litres or more
The best all-rounder if your bedroom is reasonably warm in winter.
How we choose: these are types of product matched to the criteria in this guide, not individually tested models. Check current specifications and reviews before you buy.
How to get the best results
A dehumidifier works best as part of a simple routine:
Close the door. Otherwise it’s trying to dry the whole house.
Run it when moisture peaks — the evening, and for an hour or two after you get up.
Set the humidity to around 50% and let it cycle. Our guide to the ideal humidity in a UK house explains why that’s the sweet spot.
Keep it away from walls and curtains so air can flow freely. More placement tips in how to use a dehumidifier.
Wipe the windows first thing if they’re wet — the dehumidifier then has less to pull back out of the air.
Pull furniture a few centimetres off outside walls. Still air behind wardrobes is where mould starts.
It’s also worth checking you actually have a humidity problem before buying. A cheap digital hygrometer on Amazon (opens in a new tab)(paid link) on the bedside table will tell you within a couple of nights whether the room is sitting above 60%.
What about running costs?
A typical 10–12 litre compressor model draws roughly 150–250 watts. Running one for eight hours a night costs about 32–53p at the October–December 2026 price cap rate of 26.32p per kWh, and less once it starts cycling off at your target humidity. Desiccant models draw more — often 300–650 watts depending on the setting. Our dehumidifier running costs guide has a calculator you can use with your own tariff.
When a dehumidifier isn’t the whole answer
If there’s mould on the walls, a dehumidifier will stop it getting worse but won’t remove what’s already there — see do dehumidifiers help with mould? for what to do. And if the damp is coming from a leak, rising damp or a defect in the building, that needs fixing at source. If you rent, report it to your landlord in writing.
Frequently asked questions
Is it safe to sleep with a dehumidifier on?
Yes, for a modern, well-maintained unit. Keep it on a hard, level floor with space around the vents, don't run it on an extension lead coiled under the bed, and use the auto shut-off when the tank is full. If the noise or light disturbs you, run it in the evening with the door closed and switch it off at bedtime.
Should I run a dehumidifier in the bedroom all night?
You don't have to. Many people get the best results by running it for a few hours before bed and again in the morning, when moisture from breathing and condensation is highest. If windows are streaming every morning, overnight running on a humidity setting of around 50% usually helps.
What size dehumidifier do I need for a bedroom?
A 10–12 litre compressor model or a 7–8 litre desiccant is plenty for a typical UK bedroom. Bigger units aren't harmful, but they are louder, heavier and more expensive than a single room needs.
Where should a dehumidifier go in a bedroom?
Place it near the source of the problem — often near the window or an outside wall where condensation forms — at least 20cm from walls and furniture, with the door closed so it's only drying the one room.
Will a dehumidifier make my bedroom too dry?
Not if it has a humidistat. Set it to around 50% and it will stop once the room gets there. Cheaper units without a humidity setting can over-dry a small room if left on continuously.
A plain-English guide to choosing a dehumidifier for a UK home — compressor or desiccant, the features worth paying for, and the marketing claims to ignore.
