The Xpelair Natural Air 180 Mechanical Ventilation with Heat Recovery unit (MVHR) provides balanced whole-house ventilation to prevent pollutants getting trapped inside the home. Fresh air is drawn in from outside the premises and is warmed by the stale, damp air as it is extracted to produce a healthy indoor environment. NA180 are highly efficient units featuring energy saving EC ball-bearing motors and ultra-fine G4 filters to maintain air quality. You will also enjoy a comfortable temperature without annoying draughts or cold spots thanks to the unit's 100% summer bypass and winter defrost functions.