MBC Timberframe
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Heat Recovery Ventilation

Efficient mechanical ventilation is essential in any building that utilises an airtight passive house system as a suitable source of fresh air is required to permeate through the house. While opening a window does provide a certain level of isolated ventilation, the building’s heat is quickly lost. Heat Recovery Ventilation or HRV, is an energy recovery and heat exchange, mechanical ventilation system which provides fresh air throughout a passive house. This method of ventilation dramatically improves climate control and air quality, whilst saving significant amounts of energy by reducing heating and cooling demands.

HRV Unit

The Heat Recovery Ventilation system unit discreetly supplies a constant supply of fresh heated or cooled air, delivering superior air quality without any unpleasant draughts. This highly efficient Heat Recovery Ventilation unit allows for the heat contained within exhausted stale air, coming from rooms such as the bathrooms, and the kitchen, to be extracted, cleaned and reused to heat incoming fresh air. Within a Passive House, a minimum 75% of the heat from the exhausted stale air is transferred or ‘exchanged’ to heat the fresh inflowing air by means of the heat exchanger mechanism.

Heat Recovery Ventilation Process

Heat Exchange Unit


  1. Warm, stale air is drawn out from the kitchen and bathrooms so it can be directed back towards the HRV unit.
  2. Fresh, cold external air is drawn in to the HRV unit from the outside. 
  3. Heat from the warm stale air is extracted and used to heat the fresh incoming air. Importantly, this exchange of heat is achieved without crossing and mixing stale and fresh air streams with one another. The now warm fresh air is directed to the bedrooms and living area.
  4. Stale, cold air is now exhausted out of the building.