Paul Filters

Because Passive House buildings are airtight and depend on the MVHR system for essentially all fresh air exchange, filtration quality matters more than in a leakier property — an H13 HEPA-grade supply filter can meaningfully reduce fine particulate and allergen levels indoors. It's a common upgrade for allergy-sensitive households, though it's worth checking your Paul model's fan capacity first.

Filter housing size varies by airflow capacity within both the Novus and Focus series, so two units sharing a series name can still take different filter dimensions. The full alphanumeric model code — not just ‘Novus’ or ‘Focus’ — is what confirms the exact size for your unit.

Two pieces of information on the unit's front panel confirm your exact Paul model:

• The series name, such as Novus or Focus
• The longer alphanumeric model code, which specifies airflow capacity

Both help match you to the correct filter set, especially where multiple airflow variants share a series name.

Paul units typically use an M5 filter for general dust and an F7 (ePM1) filter for fine particle and pollen filtration on the supply side, matching the airtight, well-sealed construction typical of Passive House buildings. Because these homes rely heavily on the MVHR system for all fresh air, keeping filters current is especially important for indoor air quality.

Paul Wärmerückgewinnung is a German pioneer of ventilation systems designed for Passive House and low-energy buildings, with several unit series built around very high heat-recovery efficiency. Filter selection follows the same M5/F7 logic as other MVHR brands, matched to your specific Paul model.