Zehnder MVHR filters

Zehnder ComfoAir units use two filter classes:

• G4 (ISO Coarse) — protects the heat exchanger; used on the extract side
• F7 (ePM1) — for the supply air, capturing fine dust and pollen

For most ComfoAir models we stock both a G4+F7 set and a G4+G4 set. The G4+F7 set is the better choice for allergy sufferers and homes near busy roads.

Find the exact model on the unit's front panel — for example ComfoAir Q350, Q450 or Q600, ComfoAir 350/500/550, ComfoD 350/450/550 or Zehnder EVO. That is the fastest way to match the correct filter set in our catalogue. If the label is missing, measuring the extract and supply filters directly identifies the right size just as reliably.

Yes. The ComfoAir Q350, Q450 and Q600 — and the ComfoAir E350 — all take the same filter set, available as G4+F7, G4+G4 or an activated carbon version. Older ComfoAir models (70, 160, 180, 200, standard 300/375 and 350/500/550) each take a different size, so check your model on the front panel before ordering.

Yes – filter replacement in ComfoAir Q units is designed as a user task. Switch the unit off, open the front panel, pull out the two filters (extract and supply), and insert the new ones in the same positions, following the airflow arrow on the filter frame. Close the panel, switch the unit back on and reset the filter reminder on the control panel or in the ComfoControl app, so the next reminder is timed correctly. No tools or technician are needed, and the job takes only a few minutes. For older ComfoAir models (160, 200, 350, 550) the procedure is similar, though the filter compartment may be at the side or top of the unit.

Because the F7-class supply-air filter is specifically designed to capture fine airborne particles, including pollen, it fills up faster in spring and early summer than during the rest of the year. Even while keeping to the standard 3–6 month replacement interval, it's worth visually checking the filter's condition monthly during pollen season — this helps maintain stable airflow and prevents allergy symptoms from worsening indoors.

Both original and correctly chosen compatible filters work equally effectively, provided the filter class (G4 or F7) and exact dimensions match — both types are made to the same ISO 16890 standard. When ordering online, the most important thing is to check your ComfoAir or Q model code in advance so the filter is delivered without errors. Compatible filters are typically noticeably cheaper than original Zehnder products, which is why many buyers choose them as a more economical yet equally effective alternative.