Central Extract Ventilation

Central Extract Ventilation is often referred to as MEV or Mechanical Extract Ventilation, it works by removing contaminated air from the ‘wet rooms’ – bathrooms, kitchens, utility rooms – and replaced with fresh air from trickle vents together with air leakage in the habitable rooms.

The advantages include straightforward installation, quiet operation and continuous, low-level background ventilation, with a boost facility, for example when cooking. Typically only one power supply and one penetration through the buildings envelope.

The main disadvantages are that the system wastes heat as well as creating draughts and requiring trickle vents.