UK damp, condensation and fresh air
Drier, fresher rooms, without the guesswork.
Wet windows, black mould, washing that never dries? Start with the cause, try the free fixes, and only then buy kit. Our calculators work from your own room and your own tariff.
Size my dehumidifierCheck my condensation
No health claims and no testing claims: we link to the NHS for health, and product figures are the manufacturer's own.
What dehumidifier do I need, and what will it cost to run?
Worked example
For a heated bedroom and a made-up 200 W dehumidifier run for 8 hours a day on a 25p/kWh tariff:
- Suggested type: compressor (the room is heated).
- Energy: 200 W × 8 h = 1.6 kWh a day.
- Cost: £0.40 a day, £2.80 a week, £72.80 over the October to March season (182 days).
Source: Manufacturer documentation, awaiting check
Free tools
Work it out for your home
Guides
Cause first, then the fix
- CondensationWhy condensation forms on windows and walls, how the dew point works, and the free fixes to try before you buy anything. UK guide with a dew-point checker.
- Damp: types and causesThe three kinds of damp in UK homes, how to tell them apart, and when to get a survey from a regulated surveyor.
- MouldWhat to do about mould on walls, ceilings and window seals: safe cleaning steps from official UK guidance, when it's your landlord's job, and how to stop it returning.
- VentilationHow homes get fresh air: trickle vents, extractor fans, positive input ventilation and MVHR, plus what a CO2 monitor reading tells you about ventilation.
- DehumidifiersCompressor or desiccant, what size, where to put it and what it costs to run on your own tariff. UK dehumidifier guide with a free calculator.
- Air purifiers and monitorsWhat HEPA and CADR mean, how to size an air purifier for a room, and how to read CO2 and PM2.5 monitors. No health claims, just the specs explained.
- Room by roomDamp, condensation and mould in the bathroom, bedroom, kitchen, loft, garage and conservatory: the usual cause in each room and the fix to try first.
- Renters and landlordsTenant and landlord duties on damp and mould, explained factually: Awaab's Law in England, HHSRS, and how to report damp in each UK nation.
How we work
Free fixes first
We start with the cause (moisture, ventilation, heating or a leak), not the gadget, so we'll often tell you that you don't need to buy anything. When you do, we size it and show what it costs to run.