A trickle vent is a small ventilator, usually fitted near the top of a window, that allows outside air into a room while the window is closed.
What does it do?
The inside control adjusts the opening. An outside hood helps protect it from the weather. Designs and operation vary by product. A trickle vent provides background ventilation: a regular supply of air for everyday use.
How is it different from opening a window?
Opening a window creates a larger temporary opening. Extractor fans remove air from rooms such as kitchens and bathrooms. These functions work together. A trickle vent does not replace every other part of a home's ventilation system.
What should you ask before ordering?
Discuss the vent as part of the whole window specification. Its appearance matters, but so do its size, position and suitability for the room. Two similar-looking vents may provide different amounts of airflow. If your home faces a busy road, raise the noise issue before ordering. Do not assume that an ordinary vent filters pollution.
Using and caring for the vent
Follow the instructions for the model fitted in your home. Avoid blocking or painting over its opening. Clean it only as the supplier advises; do not dismantle it based on generic internet instructions.
Do all replacement windows need vents?
That depends on the work and the home's existing ventilation. In England, Part F provides the relevant requirements. Your installer can explain which guidance applies to the work. For practical replacement-window questions, read our Part F guide.
Questions
Will a trickle vent stop condensation?
It can contribute to ventilation, but it cannot guarantee an end to condensation. The source of moisture and the rest of the building matter too.
Can a wall vent do the same job?
A suitable wall vent can provide background ventilation. Tell your installer about any existing wall vents so they can be considered with the replacement windows.
Can I order without window vents if I prefer the appearance?
Discuss the options before ordering. A suitable alternative may be possible, but signing a disclaimer does not remove the ventilation requirements.
Send photos and approximate measurements for an initial estimate. Include pictures of existing window and wall vents.
