US Patent 7802618 Thermostat operation method and apparatus

A thermostat may be placed in a heating mode when the sensed temperature is less than the lowest of the heating and cooling target temperatures by a first amount and may be placed in a cooling mode when the sensed temperature is greater than the highest of the heating and cooling target temperatures by a second amount. The presence or absence of a user may be monitored. If the thermostat is in a user absent mode, a cool setback amount may be added to the cooling target temperature and a heat setback amount may be subtracted from the heating target temperature to arrive at setback cooling and setback heating target temperatures, respectively. The thermostat may comprise a touch-sensitive screen having various display areas.