Central Mechanical Extraction & Ventilation (CMEV)

What is CMEV or QCMEV Centralised Mechanical Extract Ventilation?

  • CMEV or QCMEV systems change the air in a building by extracting waste condensate air and replacing it with fresh air from the atmosphere when required or on demand. It does not recover any heat from exhaust air.
    A CMEV system is a centralized extract fan that should have a humidity sensor to control the speed of extraction, the humidity stat works on the mean humidity of the whole house and is therefore not as sensitive as DCV. With a duct going to each wet room including the kitchen and utility. It will extract waste heat and condensate air and odours through manually adjustable ceiling valves, meanwhile, humidity-sensitive passive vents are fitted to the bedrooms, living and dining room external walls, allowing air in from outside depending on humidity these passive vents open and close automatically, This replaces the air being extracted.
  • The bottom line is that CMEV will make your home or business a healthy well ventilated environment for your family or employees as required and on demand without the need to open windows. Naturally, this includes unwanted odors. The benefit of CMEV is very noticeable in the classroom, You will notice a reduction in respiratory issues, colds and flu and improve concentration for pupils as air is more oxygenated.

Current Problems

  • Stricter regulations on Ventilation in Ireland, refer to technical guidance document TGD Part F for building regulations.
  • Higher standards for airtightness and building fabric u values.
  • Average Family producing over 10 litres of water a day, not to mention cooking and clothes drying internally due to our climate.
  • Increasing incidence of chronic respiratory problems and hay fever.

The Solution: Centralised Mechanical Ventilation system (CMEV).

CMEV system operates by use of a variable volume cenrtral extract fan, with ducts running to wet rooms, utility, kitchen and W.C. The extract fan increases and decreases speed automatically depending on the mean humidity of the building. Meanwhile humidity sensitive passive vents are fitted to bedrooms, living and dining room external walls, allowing air in from the outside depending on humidity these passive vents open and close automatically, this replaces the air being extracted.