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Insight Horizon Media

Should my double glazing have vents?

Author

Robert Miller

Published Feb 19, 2026

Should my double glazing have vents?

Broadly, for replacement double glazed windows, if the old unit being replaced doesn’t have trickle vents, then the new one does not have to have them either. New- build houses (extensions) windows will require them. When you can just as easily open the window or set it on a night latch”.

Can you put an air vent in double glazing?

Yes you can retro fit trickle vents, do you have an extractor fan going when you have a shower, if not it would be a good idea to have one fitted. Also check behind any wardrobes etc that are against any walls, and dont hang damp washing in the rooms.

Are trickle vents necessary?

Trickle Vents are a requirement under building regulations. Trickle ventilators are not mandatory unless the existing windows have them, however, it is always a good practice to consider their use when replacing windows. Replacement ventilators must be no smaller in geometric open area than the existing ventilators.

Can trickle vents be fitted retrospectively?

Lastly, it is sometimes possible to retrospectively fit trickle vents to existing plastic windows. So if you are experiencing a problem with condensation and do not have a form of background ventilation, you could consider fitting trickle vents to your existing uPVC windows.

Should window vents be left open?

Trickle vents allow controlled ventilation and fresh air into habitable rooms, freshening the stale air. Keep your trickle vents open and they should help reduce moisture – they really do work. Our advice is to leave them fully open at all times.

Can insects get through trickle vents?

Will insects be able to get in through a trickle ventilator? Not usually. An insect screen is built into outside treatments to keep insects from penetrating through the trickle ventilator.

Do trickle vents let insects in?

Since ventilators are usually operable (that is, can be opened and closed manually), you can close them during inclement weather. Will insects be able to get in through a trickle ventilator? Not usually. An insect screen is built into outside treatments to keep insects from penetrating through the trickle ventilator.

Do trickle vents prevent mould?

If it’s too cold or you don’t want to, trickle vents, which can also be fitted retrospectively, can significantly improve ventilation inside your home, helping to remove the moisture, which is key to the growth of black mould.

Do trickle vents cause heat loss?

A trickle vent is a device usually fitted at the top of a window that allows fresh air to circulate naturally through a room, and allows polluted air out. They are controllable, to give the option of having them open or closed. When used correctly, trickle vents do not contribute excessively to heat loss.

Do trickle vents make room cold?

However, while opening windows is useful, it may not be the most comfortable — especially in the winter months. Trickle vents are great because they work constantly in the background without making the home uncomfortably cold or requiring any manual input.

Where should trickle vents be fitted?

Trickle vents are designed to cut condensation, both on the inside of the windows, and on the walls. Older windows tend not to have trickle vents, but that doesn’t mean you have to replace perfectly good glazing. You can retrofit trickle vents fairly easily, providing you’re competent at DIY.

Should I close window vents in winter?

Window vents let the heat out People feel the draught and close the vent or think the room loses its heat. The purpose of trickle ventilators is providing a consistent flow of fresh air. Any cooling of the internal temperature in winter from a trickle vent is marginal. Keep your trickle vents open.