An extraction system removes air from a building, often from toilets or industrial process areas. They are commonly used to improve air quality for the building’s users.
The energy efficiency of extraction systems varies considerably depending upon their design, controls and other systems they may be combined with. One of the most important characteristics an energy assessor will look at is the Specific Fan Power (SFP). They will also consider how it is controlled. The most energy efficient systems tend to only operate when they are needed which can be achieved by using effective controls.