Why do I need Heat Recovery Ventilation?

Ventilation is essential in modern well insulated homes, not only to prevent the very visible problems associated with moisture generation, but also to provide a better indoor environment free from atmospheric pollutants with ample fresh air for healthy living. Mechanical Ventilation with Heat Recovery (MVHR) provides the most effective method of achieving energy efficient ventilation.

The key to efficient living space ventilation is controlled and balanced airflow. Traditional ventilation methods in the home rely on some form of extract to remove the moist air and pollutants, generally an extract fan or passive ventilation duct installed in the ‘wet’ rooms, where the water vapour is generated.

The extracted stale air must be replaced by fresh air from outside and this is normally achieved by natural leakage through openings in the building structure and the installation of trickle ventilators. The provision of these replacement air openings means that the ventilation rates cannot be controlled with wind pressure and direction varying the air flow, as a result the air change frequency may be as high as four or five times per hour but not necessarily in the rooms where it’s needed. Far higher than the one air change per hour generally accepted as the optimum level to maintain a fresh atmosphere in the home.

This over ventilation achieves no gain in resident comfort but certainly wastes energy and causes potential occupant discomfort due to draughts.


The effects of condensation

Rega Ventilation Limited 21/22 Eldon Way, Biggleswade, Beds SG18 8NH