What is a ventilation grille?
A ventilation grille is a grille or vent in an external wall, window, frame or door that lets air flow from outside to inside, from inside to outside, or from one room to another. The term covers a whole family of products: from the trickle vent above a bedroom window to the small wall grille that ventilates a crawl space. Grilles are usually made of aluminium, plastic or stainless steel. In Dutch the general term is ventilatierooster.
Types
- Window and frame vents (trickle vents): in or above the glazing or in the frame, supplying fresh air.
- Self-regulating vent: a flap restricts the opening in strong wind, so there is no draught in a storm.
- Electronically controlled vent: opens and closes using sensors, for example for CO2.
- Acoustic vent: reduces outside noise, see acoustic trickle vent.
- Door or transfer grille: lets air flow from one room to the next, for instance towards the bathroom or toilet where air is extracted.
- Wall grille: for a crawl space or cavity, often mouse-proof, see sleufrooster.
Application
With natural air supply, window vents are the main source of fresh air. Manufacturers rate capacity in dm³/s (litres per second) per metre of vent at a 1 Pa pressure difference; for common Dutch window vents this is roughly 10 to 19 dm³/s per metre. In the Netherlands, the Besluit bouwwerken leefomgeving (Bbl, the Dutch building regulations) requires 0.9 dm³/s per m² of habitable area in a new home, with a minimum of 7 dm³/s. A 30 m² living room therefore needs 27 dm³/s: about 2 metres of vent rated at 13.5 dm³/s per metre. Other countries set their own requirements, so check your local building regulations.
Tips
- Keep vents open: a closed vent is the most common cause of damp problems and stuffy air.
- Supply and extract go together: without a transfer opening (a gap under the door or a door grille), mechanical extraction works poorly.
- When replacing glazing: allow for the glass deduction and the height of the vent.
- Clean regularly: vacuum the vent and any insect mesh a few times a year.
- No draughts: in exposed locations or tall buildings, choose a self-regulating vent.
Related terms
- Acoustic trickle vent
- Sleufrooster
- Natural ventilation
- Mechanical ventilation
- Ventilation
- Crawl space
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