4 Inch External Wall Vent Cover with Sound Baffle & Air Filter - Non-Flammable Hood for Extractor Fans, Heat Recovery & Ventilation Systems - Draft Proof & Energy Saving [Class Black

Blauberg AH-10-100-BLACK External Wall Wind Sound Baffle Vent Cover Draft 4" 100mm Product Description A brilliantly designed external wall vent that meets the needs of any ventilation system. They look great, reduce internal and external noise, and are easy to fit onto any external wall. The Blauberg AH-10 vent cover will flush fit to an external wall and will also accept a 100mm 4" diameter duct depending on which size you order. When used and an air intake vent serving a heat recovery system (MVHR), positive input ventilation (PIV), mechanical extract system (MEV) or single room heat recovery unit, air is drawn in from opposite sides of the vent through louverd vents. Air also passes over a sound adsorbing lining to dampen airborne noise. This ensures weatherproofing and reduced noise without the need of a mechanical shutter or noisy back draft flap. As an air extract vent, expelling dirty air from a heat recovery system, bathroom extractor fan or kitchen cooker hood, air passes ove