Method of maximizing the efficiency of an environmental control system including a programmable thermostat

摘要

A process which is periodically executed by a programmable thermostat of a heating and cooling system which controls the temperature of a defined space within a structure subjected to a variable external environment. The process advances by an increment of time, DELTA t, when the set point temperature of the thermostat changes from an occupied set point temperature to an unoccupied set point temperature. The magnitude of DELTA t is a function of the thermal lag of the structure, its external environment, and an amount of temperature change that is acceptable to occupants of the space. Each time the process is executed, the magnitude within predetermined limits of DELTA t to be used the next time the process is executed is recalculated.