Condensation
Condensation is water from the air in your home landing on something colder than the air. Every home makes moisture: breathing, cooking, showers and drying washing all add it. When that moist air meets a cold window or outside wall, it cools to its dew point and the water comes out as droplets.
The good news is that most condensation can be cut down without buying anything. Start with the free steps, measure with a cheap hygrometer if you can, and only then think about a dehumidifier.
Tools
Guides
- Why are my windows wet in the morning?Why windows get wet overnight, what the dew point has to do with it, and the free fixes that stop it. With a dew-point checker for your own readings.
- How to stop condensation without buying anythingFree ways to cut condensation at home: ventilation, making less moisture, steady heating and wiping. Do these before you buy a dehumidifier.
- Why a humidity percentage needs a temperature beside itRelative humidity depends on temperature, so a percentage alone can mislead. How to keep paired readings, with Met Office definitions.
Start here
- Let moisture out. Open trickle vents and leave them open, and run extractor fans when you cook or shower.
- Make less of it. Put lids on pans, dry washing outdoors where you can, and shut the door on a steamy bathroom.
- Keep surfaces warmer. Steady, low heating keeps walls and glass above the dew point better than short blasts.
- Wipe it away. Wipe wet windows and sills in the morning so water doesn't sit on frames and seals.
Check your own readings
Our condensation checker turns your room temperature and humidity into a dew point, and tells you whether a cold window or wall at a given temperature is likely to get wet.
Condensation and dew-point checker
Enter your room temperature and humidity to get the dew point, see whether a cold window or wall is likely to get wet, and get the free fixes to try first.
Sources
- Energy Saving Trust advice on condensation and ventilation (Energy Saving Trust), awaiting check
- NHS guidance on damp and mould and your health (NHS), awaiting check