Normal occupancy sensors only switch the lights off, leaving the air-conditioner running. The HVAC facilitates the switching of both lighting and HVAC circuits greatly increasing energy saving. The HVAC control gear is connected to any occupancy sensor, the lighting load and the air-conditioner. A separate timer is provided to enable the air-conditioner to switch off long after the lights are extinguished thereby preserving the room temperature.

The user can specify the delay which air conditioners etc will remain on after the occupancy sensor has switched the lights off. A buzzer will sound 3 minutes before the HVAC controller is about to switch the appliance off. Once the HVAC unit has switched the air-conditioner off, it will wait for movement to be detected by the occupancy sensor, if movement was detected it will restore power to the appliance.