Ventilator Filter

Zehnder Units require two (2) filters. The red F7 filter is a MERV 13-rated filter, which is a hospital-grade fine-particle filter which should be placed on the side of the unit where the air comes in from outside to keep the air entering the home free of these particulates. The black G4 filter is a MERV7/8-rated filter, which captures dust, pollen, mold spores and dust mites. This filter should be placed on the side of the unit where the extracted air from the home is returned in order to protect the unit core. Filters should be replaced every six months, or more often if they appear dirty.