Mechanical Extract Ventilation, or MEV, provides continuous low level extraction from kitchens, bathrooms, shower rooms, utility rooms and toilets. The air extracted from these rooms is ducted to a central extract fan which then discharges the air moist stale air to the outside. The system runs continuously and then a particular room is being used, e.g the bathroom the the system operates at a boost rate to accelerate the removal of the moist air. The replacement air is normally provided via structural leakages in the property so it may not be suitable for properties that have the very highest levels of air tightness.

As this system runs continuously having it installed and set up correctly is very important to maximise efficiency and keep noise levels to a minimum. A well installed system won’t be noticeable at all unless the system is running on boost but that wouldn’t be any louder than a normal extract fan would be.