You need to stop closing your window vents in winter – experts reveal you're doing more harm than good

Yes, it's really cold outside. Yes, it's the time of year when condensation, damp and mould really thrive, but experts want you to stop closing your window vents in winter, as keeping them closed can actually contribute to these winter problems.

While you may be tempted to keep your window vents (also known as trickle vents) shut during the winter to stop any heat escaping, it is ultimately a bad idea. Especially, considering that keeping them open is a lesser-known hack that prevents condensation build-up on your windows.

That’s right, if you want to get rid of condensation on windows, you need to leave your vents open. Here’s everything you need to know, according to the experts.

Should you close your window vents in winter?

‘While іt іs tempting tо seal every gap when the temperature drops, you should generally keep your window vents (often called trickle vents) open,' explains Jo Trotman, Sales and Marketing Manager at The Residence Collection.

'Closing them might keep a tiny amount оf heat in, but іt traps stale, moisture-heavy air inside your home. Modern homes are designed tо be airtight, and these vents act as the ‘lungs’ оf the property, allowing іt tо breathe without the massive heat loss associated with opening a full window.'

Ventilating your home will not only improve its air quality, but is also a vital (and free) tool to use to combat condensation during winter, which in turn, can cause damp and mould. In fact, it’s even recommended that you take this further and burp your home.

This refers to the German practice of Lüften, which uses shock ventilation to let warm, moist air escape and replace it with dry air. You do this by opening all your windows and doors for 15 minutes every morning - yes, even when it’s January!

‘Ideally, vents should remain open throughout the day and night because they provide a gentle, continuous airflow without causing significant heat loss. The only time you might consider closing them is during extreme weather or if you notice draughts. Otherwise, consistent ventilation is key,’ adds Simon Browne, product expert at Luxaflex.

‘Leaving vents open is one of the simplest ways to tackle condensation and damp. Moisture builds up when warm air meets cold surfaces, and without ventilation, it lingers, creating the perfect environment for mould. Vents allow that excess humidity to escape, protecting your home and making it a healthier place to live.’

Not all windows have trickle vents, and if you don’t, it is possible to install them yourself - for example, with this £13.70 easy fit kit from Amazon. Alternatively, you should focus on regularly opening your windows to allow ventilation or invest in one of the best dehumidifiers to suck up excess moisture.

Anti-condensation essentials

If you’ve been wondering: ‘Should you close your window vents in winter?’ The answer is a definitive no. In order to tackle condensation on windows, you need to leave your vents open. Simple.