5 things that help you stop condensation streaming down your windows

One wet load releases roughly two litres of water as it dries, and indoors every drop goes straight into the air and lands on the coldest surface in the house — your window — by morning. This is the single biggest hidden moisture source in most homes in winter, and it's the one nobody connects to the streaming glass three feet away. Worse, a vented tumble dryer that isn't actually ducted outside is just a laundry-shaped humidifier pumping that water back into the room.

The fix for condensation is swapping warm, moisture-laden indoor air for cold dry outdoor air — and cold air is dry air, so once you let it in and it warms up it can soak up moisture instead of dropping it on the glass. You do this far better with a brief, wide cross-breeze than a window cracked all day: the Germans call it stosslüften, and because air reheats far faster than your walls and furniture cool, you barely lose any warmth. A window left on a tiny tilt for hours does the opposite — it bleeds heat all day without ever properly clearing the air.

An uncovered pan of pasta or potatoes can throw off more moisture in fifteen minutes than a person breathing out all night, and most of that steam drifts off to condense on the nearest cold window rather than going up the hood. The mistake almost everyone makes is timing: they switch the extractor on once the kitchen is already foggy, by which point the steam has already migrated to colder rooms. A lid keeps the water in the pan, and the steam doesn't vanish the second you plate up — so leave the hood running for ten minutes after.

This one doesn't stop condensation — it stops what condensation turns into. On the coldest nights you'll still get a little water on the glass, and that's harmless, but it runs down and pools on the bottom rubber seal and the painted frame, and within a week or two that's exactly where the black speckly mould takes hold. People diligently wipe the middle of the pane they look through and ignore the one spot that actually matters, then spend March scrubbing spores out of the silicone.

If you've cut the laundry and steam, you're airing daily, and one room still streams every morning — often a north-facing bedroom or a flat where cooking, drying and breathing all happen in a small space — that room is simply making more moisture than ventilation can shift. A dehumidifier pulls the water straight out of the air into a tank you tip down the sink, and it's the only thing on this list that addresses the cause directly rather than managing symptoms. But prove you need one first: a cheap hygrometer tells you whether the air is genuinely too humid or you're just chasing a draught.