The installer should place the passive vent on an external wall, near the ceiling, above head height. A passive vent is a type of non-powered ventilation. Passive vents are most commonly fitted in habitable rooms like bedrooms and l ounges.
Blauberg Condensation Damp Control Passive Wall Intake Vent Grille Kit
100mm White Passive Wall Intake Vent Grille Cover - Mould & Condensation Control
Condensation Control Passive Wall Intake Vent Grille Cover 100Mm (4 Inch) Spigot
Blauberg 100mm Passive Wall Vent Grille with Adjustable Iris & Filter
Blauberg Condensation Mould Control Passive White Wall Intake Vent 100mm