44 01276 408404 | www.greenwood.co.uk 01276 408404 | www.greenwood.co.uk 45 Continuous Mechanical Extract Ventilation (MEV) Building Regulations MEV products comply with System 3 of the Building Regulations under Mechanical Extract Ventilation. These products continuously extract humid, stale air from a home’s wet rooms to one discreet, centralised unit mounted in a loft or cupboard and exhaust it to the outside. Fresh air is supplied to the habitable rooms around the home via background ventilators such as window vents. The objective A system that provides dedicated extraction from the areas around the home where moisture is generated. A discreet, centrally positioned fan works around the clock to exhaust stale air to the outside whilst keeping nuisance running noise to a minimum. The method A central unit is positioned in a loft or cupboard space and ducted throughout the home to each wet room. Fans run continuously at very low levels to ensure a consistent level of extraction. High speed operation is generally activated via a light switch and can include adjustable overrun timer options. Automatic humidity sensing can also be used to protect the dwelling from high levels of moisture. Habitable rooms contain passive ventilation, usually in the form of window ventilators, which are equally installed around the property in accordance with current Building Regulations. The outcome 1.  An easy-to-install central extract system to comply with System 3 of the Building Regulations. 2.  Continuous low level background ventilation for optimised indoor air quality. 3.  Ultra-simple operation with limited intervention required from occupants. 4.  Low energy use and low running noise. 5.  Compact and discreet system which is suited to both houses and apartments. System 3: Central Mechanical Extract Ventilation A powerful centralised extract ventilation that is not only discreet but energy efficient for the whole house. A single loft or cupboard mounted unit extracts humid, stale air from wet rooms around the clock. MECHANICAL EXTRACT VENTILATION (MEV) MECHANICAL EXTRACT VENTILATION (MEV) Centair Range CMEV.4e/CMEV.4eHT The Centair range offers efficient whole house extract ventilation for houses and apartments  One of best energy efficiency performances on the market with an SFP as low as 0.16 w/l/s  EC Motor Technology for low energy consumption and low running costs for end users  Low running noise within the home  Discreet ventilation – concealed in loft space or cupboard  4th Extract ports with options for 5th if required in larger properties  CMEV.4e/HT Model Includes Greenwood SMART Technology such as SMART humidity sensing and timer control to reduce nuisance noise, nuisance running and energy wastage Refer to individual product specifications at www.greenwood.co.uk 44 01276 408404 | www.greenwood.co.uk Fan uses real time monitoring to know what the ‘normal level’ of humidity is in the home. The real time monitoring is looking for man-made rapid increases in humidity that are created from showers, cooking and hanging washing. Once a spike in humidity is sensed from the normal level it will activate the fan. This eliminates any nuisance running, unnecessary heat loss and energy usage associated with ambient humidity rises throughout the day and night.  No set up required by installer  No tampering by occupant to turn off the humidity sensing  No nuisance running or noise from ambient humidity sensing  No unnecessary heat loss from homes due to overventilation  No energy wastage to occupant Greenwood HumidiSMART™ Greenwood HumidiSMART™ looks for a rapid increase in humidity and only then changes to boost mode. TIME RELATIVE HUMIDITY Rapid humidity increase Fan in Boost mode Fan in Trickle mode (continuous) or Off (intermittent) mode Generic preset threshold Fresh air Background Ventilators Extract air Central Extract Ventilation Unit Exhaust air