Mechanical Extract Ventilation (MEV)

MEV stands for Mechanical Extract Ventilation and is a form of whole house ventilation solution.

MEV or Mechanical Extract Ventilation are systems that provide continuous ventilation using multi point extracts. The centralised systems draw moisture-laden air from multiple wet rooms of a property. All our MEV systems are reliable, long-lasting and operate at low noise levels.

MVHR offers a completely balanced system, providing both extract ventilation and supply of fresh heated air. It extracts moisture laden air from wet rooms/kitchens and supplies fresh, filtered heated air, to habitable rooms such as bedrooms and living rooms. MEV is also a whole house ventilation system but provides just extract ventilation from wet rooms and kitchens.

Both MEV and MVHR systems are most suitable for new properties rather than retrofit, but MVHR systems do require a more airtight property where virtually all of the air flow can pass through the heat exchanger, if they are to perform efficiently.

With inner cities obviously having higher pollution levels, MVHR systems are seen as more suitable because of the filter element, but in apartment blocks it’s often the case that only the first four floors are fitted with MVHR and the remaining with MEV as polluted air is heavier and therefore stays closer to the ground.

With Mechanical Extract Ventilation, moist air is actively drawn from rooms throughout the house and vented to the exterior.  This process creates a slight pressure differential with the equilibrium that causes fresh air to be drawn in from outdoors to replace it.  In a PIV (Positive Input Ventilation) system, the air is actively drawn in from the exterior of the building to create a positive air pressure which causes the moist air to be pushed outside.

Mechanical Extract Ventilation relies on a central extractor fan unit which is mounted in your loft or a cupboard.  This central unit draws air in from the other rooms of your house through ducts installed in the walls and then discharges the air outside through a single vent.