Mitsubishi Lossnay VL-350 Filters

No. Lossnay is the name of Mitsubishi Electric's heat-recovery ventilation line and its heat exchange element — the filters themselves are conventional G4 filters that keep dust off the Lossnay core. We stock sets for the Lossnay VL-250, VL-350 and VL-500 (originals) and the LGH-15RVX to LGH-100VX (house brand). The model number on the casing label confirms the exact size.

The Lossnay filter sets we stock are all G4. VL-series units and the LGH-15RVX take a set of two G4 filters, while the larger LGH-25RVX to LGH-100VX take a set of four. G4 protects the Lossnay core from coarse dust and keeps airflow steady.

Lossnay units follow the standard 3–6 month interval, although many models have a built-in maintenance indicator that warns when airflow drops due to a dirty filter. It's worth treating this indicator as a useful reminder rather than the only criterion for when to replace the filter — especially in urban environments or near busy streets, where the filter gets dirty faster than the calculator suggests.

Filter compatibility generally stays within the same series and the same housing generation, but Mitsubishi has changed internal filter dimensions in some model updates, even while keeping a similar product name (e.g. within the VL or LGH-RVX series). The safest approach is to choose a filter based on the exact model number, or, if you can't find it, to measure the old filter directly before ordering a new one.

The larger Lossnay LGH units — LGH-25RVX, 35RVX, 50RVX, 65RVX and 100VX — take four filters in total, so our sets for these models include all four G4 filters. Change them together to keep the airflow balanced. The LGH-15RVX and the VL-series units take two filters.