Mechanical Ventilation with Heat Recovery (MVHR) is a ventilation system that is now widely used in well-insulated and energy-efficient homes, and is a mandatory constituent in ‘Passivhaus’ buildings. MVHR systems are critical to meeting Building Regulations for energy conservation and indoor air quality. Having a good understanding of these systems is essential for architects, tradespeople, homeowners and builders, since they are key to the creation of energy-efficient environments that are a pleasure to live in.
MVHR systems are designed to run all year, controlling ventilation by removing stale air in the home from multiple rooms and providing fresh outdoor air. They are not to be confused with MEV (Mechanical Extract Ventilation) systems, which are shown to waste around nine times more energy than its MVHR equivalent.
The ability to recover heat is what distinguishes MVHR from other ventilation systems as it effectively transfers heat from the extracted stale air to the incoming fresh air. This heat exchange mechanism, which is passive in nature, keeps the inside temperature comfortable while minimising heat loss. MVHR systems can also help to enhance air quality for people with respiratory illnesses and allergies, as well as minimise common problems that affect many homes,
