Have You Changed Your Filters Recently?


Filters are an important piece of your ventilation system. They keep harmful air pollutants, bacteria and dust from entering your home through your ventilation—and they protect your ventilation unit too. We recommend changing your filters every 6 months; this time may vary depending on your location and environment.  

Zehnder offers three types of filters, all of which can be ordered through our online filter store. 

Unit filters go in the filter slots on your Zehnder unit. There are two types of unit filters available. The red F7 filter is a MERV 13 filter, which traps microscopic particles such as dust and dust mites, pollen, mold spores, and many bacteria. It is used on the air intake side of the unit to filter the outside air coming into the home 

The black G4 filter is a MERV 7/8 filter which goes on the exhaust side of the unit to protect the core from household dust, fibers and pet dander.  

For maximum efficiency, both unit filters should be replaced at the same time.  

Return register filters fit behind the extract valves or grilles in the interior of the home. They are available for both the round (Luna or Venezia) or rectangular (Roma) extracts. 

ComfoWell filters fit in the filter casing next to the ComfoWell silencer. Not all systems have this optional filter casing component. Two types of filters are available for the ComfoWell. The orange CW-F9 filter is a MERV 15 filter, which traps many of the smallest particles including pollen, mold, pet dander and other common allergens and pollutants. These are a good option for allergy sufferers. 

The black activated carbon filter traps fine particles and odors from smoke and auto exhaust and volatile organic compounds (VOCs). They are a good option for urban and industrial areas or areas frequently affected by wildfires. 

Unit and return filters can be cleaned monthly by gently vacuuming to remove visible particles (activated carbon filters should not be vacuumed). Cleaning and replacing filters regularly as recommended will ensure the highest air quality in your home as well as protect your unit and its components from damage.  

Detailed instructions for changing unit filters can be found in the User Manual for your unit, found on our website. Instructions for changing the Comfowell filter can be found here, and videos for changing cone and rectangular return filters can be found on the website as well.