Surface mounted fans can be wall or ceiling mounted and have a centrifugal impeller designed to overcome longer duct runs. The fan has an on/off pull cord switch. Switching off will activate the overrun Timer
These carry on running for an adjustable period - usually about twenty minutes after it has been switched off - but this can be set to anywhere between two and thirty minutes. The benefit is that the fan will continue to operate when the room is no longer in use, continuing to clear the moisture.timer. The fan will switch off at the end of the overrun time which can be altered by adjusting the sensor. The fan's integral Humidistat
Humidistat fans incorporate sensors that continually monitor the surrounding environment and when the humidity climbs over a certain level the fan turns on automatically. The fan stops automatically once the humidity levels have been reduced to 'normal'.humidity sensor will operate the fan whilst the relative humidity exceeds the pre set activation point. The fan back plate can be removed and fully installed before the fan and motor assembly are fixed in place. The IP rated 44 fan can be located in Zones 1, 2 or Outside.