The SF90SVIHT is a Low voltage surface mounted centrifugal fan with humidistat and run-on timer.
Humidstat fans have a sensor in them. This detects moisture in the air. When a set humidity point is reached the fan will switch on. There are two types of sensor – Traditional and Digital/Intelligent.
Traditional. Work by having a fixed humidity level which, when reached, the fan activates. Traditional humidistats work well but as natural levels of humidity rise and fall between summer and winter, they can become more or less sensitive to switch on periodically.
Digital/Intelligent. Have no fixed humidity point for activation. Instead they constantly measure humidity levels and only activate when man-made spikes in humidity - caused by showering, bathing or cooking - are detected. Consequently they are more responsive to run only when required
Safety Extra Low Voltage (SELV) fans have been designed for increased safety when installing fans within a bath or shower spray area. SELV fans have an isolating transformer(which is located in an area away from the fan) and reduce the voltage to 24v so that in the unlikely event of a fan fault the electrical charge is at a safe level. SELV fans are the safest option for use in 'wet' areas offering increased peace of mind and have a safety rating of IP57 and can be located in Zones 1, 2 or Outside. Transformer included