METHOD FOR CONTROLLING AN AIR CONDITIONING SYSTEM USING AN ECONOMIC BALANCE POINT AND A CAPACITY BALANCE POINT

A computer-implemented method is provided of controlling a heating, ventilation, and air-conditioning (HVAC) system having a heat pump and an auxiliary heater to heat an inside zone, the method comprising: setting values for an economic balance point and a temperature set point; setting a capacity balance point to be equal to the economic balance point; measuring an initial inside temperature in the inside zone and an outside temperature outside of a structure containing the inside zone; determining that the initial inside temperature is lower than the temperature set point; determining that the outside temperature is greater than the capacity balance point; activating the heat pump to heat the inside zone; waiting a heating interval while the heat pump is active; determining that the heat pump is not effective in heating the inside zone; and setting the capacity balance point to be equal to the outside temperature.