A device for controlling an
HVAC system in which opening a door or window for more than a shutdown
delay period causes the fan and compressor to be deactivated, but opening and closing the door or window for less than the shutdown
delay period does not affect the fan and compressor. Reactivation of the compressor is delayed for a startup
delay, in order to avoid overcycling of the compressor and the additional
wear and tear and maintenance that would be caused thereby. Preferably, the door / window sensors are
wireless for ease of installation and maintenance. Optionally, an
occupancy sensor and occupancy
timer are provided to turn off the
system if the room is unoccupied for an unoccupied
delay time. Optionally, a secondary
thermostat with energy saving settings is provided so that if the room is unoccupied for the occupancy delay, then instead of being shut off, the
HVAC system will be operated at energy saving settings.