Fresh Air Heat Recovery Ventilation

How Does it Work?

Designed in Japan for New Zealand conditions, the Lossnay Fresh Air Ventilation system works by extracting stale air from inside your house to remove damp, odours, dust, bacteria and gasses. This air is then replaced with allergen reduced fresh air from outside (unlike some systems that recycle it from the dust-filled attic). Where Lossnay gets really clever is with its environmentally friendly 'Energy Recovery' system. Put simply, energy within the stale air can be recovered and used to pre-heat or pre-cool the fresh air being vented in. So it warms the fresh air in winter, and cools it in summer.

Lossnay energy recovery system

This unique system recovers heat energy present in the stale extracted air, the Lossnay core uses this energy to pre-heat fresh air as it is transferred inside. This also works in the reverse, if the outside temperature is higher than preferred levels, the inside air will be cooled by extracted air. The process is as follows.


  1. The stale air extracted from your home is (RA) Return Air. Return air can contain high levels of CO2, odours and other pollutants. This return air stream also contains energy that Lossnay can recover, which is often not the case with other ventilation systems.
  2. As the stale Return Air is removed, Lossnay’s core ‘recovers’ the useful energy from it. The air is then exhausted (EA) outside along with the unwanted pollutants.
  3. Outdoor Air (OA) is introduced to provide fresh air. It is first filtered, then passed through the Lossnay core. This allows it be pre-heated in winter (or pre-cooled in summer) using the energy recovered from the Return Air.
  4. Supply Air (SA) then enters your house as fresh pre-heated or pre-cooled air.

Learn more on how it works - LGH core example

How Does it Work?