Patent ID: 8136738

Claim:
A control system for controlling a Heating, Ventilation, and Air Conditioning (HVAC) unit associated with an enclosure, the control system being configured to control the environmental conditions within the enclosure by controlling the operation of the HVAC, the control system comprising: an occupancy sensor for sensing the presence of an occupant within the sensor's field of evaluation in the enclosure and providing such information to a receiver; an activity sensor capable of sensing a change in status of a means of access to said enclosure and providing such information to a receiver; a receiver configured for the reception of information from said occupancy sensor and said activity sensor; and at least one controller in communication with said receiver, said controller capable of monitoring environmental conditions in the enclosure and being programmable to control the environmental conditions by driving the HVAC according to a set of established instructions in response to the information obtained by said receiver from both said occupancy sensor and said activity sensor; wherein information received from the activity sensor is configured to initiate a time period during which the occupancy sensor is configured to search the enclosure for an occupant, and wherein the controller is configured to take control of the HVAC operation after expiration of the time period when the occupancy does not detect the occupant during the time period.