Quick answer
For a damp bedroom or flat with mould on the walls, a 12-litre compressor dehumidifier set to around 50% humidity is enough for most UK homes, and the Pro Breeze 12L/Day Dehumidifier is our pick: rated 4.6 stars across 5,692 Amazon.co.uk ratings, with a humidistat you can set between 30% and 80%. If the room sits below about 10°C, choose a desiccant model instead. For a whole house over 50 m², step up to the AEOCKY 25L/D.
Black spots on a bedroom wall, wet window sills every morning and a musty wardrobe all have the same cause: warm indoor air carrying more moisture than the cold surfaces can hold. A dehumidifier pulls that water out of the air so it stops settling on walls and glass. It does not kill mould that is already there, and it cannot fix a leak or rising damp, so treat it as the tool that stops condensation coming back. The four picks below were chosen from Amazon.co.uk listings with large numbers of buyer ratings, read on 15 October 2026.
Our picks
Pick 1 · Best overall for damp bedrooms
Pro Breeze 12L/Day Compressor Dehumidifier
Best for: A bedroom, box room or small flat with condensation and mould spots.
Check price on Amazon.co.ukThis is the sensible default for a typical UK condensation problem. Set it to 50% and leave it on auto: the built-in sensor reads the room and stops the compressor once the target is reached, which keeps running time down. The listing quotes under 38 dB, quiet enough for a bedroom. The weak point is the 1.8 litre tank; in a room that has been damp for months, expect to empty it daily in the first week, or run the hose to a sink or drain. Keep the room door shut while it works so it dries one space properly.
Pros
- Humidistat switches it off at your chosen level
- Hose outlet for continuous draining
- Small footprint for a compressor unit
- Sleep mode for bedrooms
Cons
- 1.8 L tank fills fast in a very wet room
- Compressor units lose output in cold rooms
Key specs (from the listing)
- Type:
- Compressor
- Extraction:
- 12 L/day (title)
- Humidity setting:
- 30–80%
- Tank:
- 1.8 L, hose outlet
- Noise:
- under 38 dB (listing)
- Timer:
- 24-hour
- Award:
- Which? Best Buy 2025 (per listing)
Pick 2 · Bigger tank alternative
Pro Breeze OmniDry 12L/Day Dehumidifier
Best for: Damp homes where you want fewer tank empties without a bigger machine.
Check price on Amazon.co.ukThe OmniDry shares its controls with our first pick: auto, continuous and sleep modes, a 24-hour timer and the same humidity range. The practical difference is a 2 litre tank instead of 1.8, which matters when you cannot run a hose. The listing does not give a decibel figure, so if the unit will sit next to a bed, the first pick is the safer choice on noise. Both are refrigerant (compressor) machines, so they work best in a heated room.
Pros
- Slightly larger 2 L tank than the standard Pro Breeze
- Same 30–80% humidistat and timer
- Wheels for moving room to room
Cons
- No noise figure on the listing
- Same cold-room limits as any compressor model
Key specs (from the listing)
- Type:
- Compressor
- Extraction:
- Up to 12 L/day
- Humidity setting:
- 30–80%
- Tank:
- 2 L, hose outlet
- Modes:
- Auto, continuous, sleep
- Timer:
- 24-hour
Pick 3 · Quietest, Quiet Mark
MeacoDry ABC 10L Dehumidifier
Best for: Flats and light sleepers who want the lowest noise.
Check price on Amazon.co.ukMeaco is the brand UK damp specialists mention most, and this model suits a flat or small house. Its 2.6 litre tank is the biggest among the compact picks, and the listing's 35 dB Quiet Mark rating makes it the one to put in a nursery or next to a desk. The 10 litre daily rating is lower on paper, but in a single closed room with condensation that is rarely the limit. Auto-defrost helps it keep working in a cool bedroom, though below 10°C a desiccant unit is still the better tool.
Pros
- Largest tank of the three compact picks
- Quiet Mark award for low noise
- Auto-defrost for cooler rooms
- Child lock
Cons
- Lower 10 L/day rating
- Fewer modes than the Pro Breeze
Key specs (from the listing)
- Type:
- Compressor
- Extraction:
- Up to 10 L/day
- Tank:
- 2.6 L, hose spout
- Noise:
- 35 dB, Quiet Mark (listing)
- Laundry mode:
- 6-hour run, then off
- Extras:
- Auto-defrost, child lock, 24-hour timer
Pick 4 · Best for whole houses
AEOCKY 25L/D Compressor Dehumidifier
Best for: Whole-house damp, after a leak, or a cold, damp ground floor.
Check price on Amazon.co.ukCapacity figures only mean something with the temperature and humidity behind them, and this listing gives both: 25 litres a day at 35°C and 95% humidity, 20 litres at 30°C and 80%. A UK room at 18°C will produce far less than either number, which is why a bigger machine helps in a large or very wet home. Pick it for a ground floor flat that never dries out, or after a leak has soaked a room. For one bedroom it is more machine than you need.
Pros
- Highest capacity on this page
- States its test conditions, which few listings do
- Rated to keep working down to 10°C
Cons
- Larger and heavier than a 12 L unit
- Newer brand with a shorter track record
Key specs (from the listing)
- Type:
- Compressor
- Extraction:
- 25 L/day at 35°C/95% RH; 20 L/day at 30°C/80% RH
- Area:
- Homes over 50 m² (listing)
- Low-temperature use:
- Down to 10°C (listing)
- Noise:
- 40 dB at lowest speed (listing)
- Drainage:
- Tank with auto-stop, or continuous
Buying guide
How big a dehumidifier do you need?
Daily ratings are measured in warm, very humid test rooms, so a 12 litre unit will not remove 12 litres from a 17°C British bedroom. For one or two rooms with condensation, 10 to 12 litres a day is plenty. For a three-bedroom house, a flat that has had mould for years, or drying out after a leak, look at 20 litres or more. Run it with internal doors shut so it dries one area at a time, then move it. A humidity reading that settles between 40% and 60% tells you the size is right.
Compressor or desiccant?
Compressor (refrigerant) dehumidifiers are cheaper to run in a heated room and pull more water at normal room temperatures. Desiccant models use a heated absorbent wheel, so they keep working in a cold garage, conservatory or unheated bedroom and give off a little warmth. If the room stays above about 15°C, buy a compressor model. If it regularly falls below 10°C, buy a desiccant one such as the Meaco DD8L or EcoAir DD1 on our drying-clothes page.
Setting the humidity level
Mould struggles to grow when indoor relative humidity stays below about 60%. Set the humidistat to 50% for a room with an active problem and 55% for maintenance. Going much lower wastes electricity and can leave skin and eyes dry. A separate hygrometer in the room is a useful check, because a sensor inside the dehumidifier reads the air right next to the machine.
Who should not rely on a dehumidifier alone
A dehumidifier treats damp air, not wet walls. If a patch of damp stays wet in dry weather, sits low on a ground floor wall with a tide mark, or appears under a bathroom or next to a pipe, the cause is likely rising damp, penetrating damp or a leak. Those need the source fixed by a builder, plumber or damp surveyor first. Mould covering more than about a square metre should be assessed rather than wiped, and anyone with asthma or a weakened immune system should not clean it themselves.
Questions people ask
Do dehumidifiers get rid of mould?
No, a dehumidifier stops new mould growing but does not remove what is already there. It lowers the humidity that mould needs. Clean existing spots with a mould remover first, let the area dry, then run the dehumidifier at around 50% so the surface stays too dry for regrowth.
Where should I put a dehumidifier for damp?
Put it in the dampest room, away from walls and curtains, with the door closed. It needs about 20 cm of clear space around the vents. In a bedroom, place it near the wall or window where condensation is worst. Move it between rooms once each one holds below 60% humidity.
Should I run a dehumidifier all day?
Run it on auto rather than all day. With the humidistat set to 50%, the machine stops once the room is dry and restarts when humidity rises, which keeps running costs down. In the first week of tackling a damp room it may run almost constantly, and that is normal.
What size dehumidifier do I need for a 3 bedroom house?
A 20 litre a day model suits most three-bedroom houses when moved between rooms or placed on a landing with doors open. A 12 litre unit can cope if the problem is limited to one or two rooms. Very damp homes or homes drying after a leak benefit from 25 litres or more.
Is a dehumidifier or an air purifier better for mould?
A dehumidifier is better for mould because it removes the moisture mould needs. An air purifier with a HEPA filter only catches spores already floating in the air. If someone in the home has allergies, run both, but buy the dehumidifier first.