Zehnder ComfoAir 200 Filter Set, ISO Coarse / ISO ePM1 (G4 / F7), 2 pcs 400 100 086 The seal between the external

The seal between the external grille and the duct provides a weatherproof seal

A PIR Motion sensor

Consequently they are more responsive to run only when required

QT120MST 120mm Two speed

An integral flow straightener

Zehnder ComfoAir 200 Filter Set, ISO Coarse / ISO ePM1 (G4 / F7), 2 pcs 400 100 086 The seal between the externalIdeally, filters should be inspected monthly and given a light vacuum to remove dirt and debris. Filters will eventually become blocked with residual debris and should then be replaced. Generally, blocking will occur every 6 12 months depending on the location (near busy roads or inner city areas tend block more quickly than remote country settings). Zehnder P N 400 100 013