Method of operating and method of controlling a heating, ventilation and air conditioning system for improved vehicle fuel economy

摘要

A method of operating a heating, ventilation and air conditioning system called an HVAC system in a vehicle having an engine operating in a high efficiency mode and a less efficient mode in terms of fuel economy, the method comprising the steps of: (a) a Refrigerant compressor is operated to cool a passenger compartment and to charge a thermal cold storage device; (b) it is determined whether a cold charge in the thermal cold storage device has exceeded a predetermined threshold; (c) a compressor cycling mode is switched on in which the refrigerant compressor is switched off if necessary and the thermal cold storage device can be used to cool the passenger compartment when the cold charge in the thermal cold storage device has exceeded the predetermined threshold; (d) it is detected whether the engine is operating in high-efficiency mode; (e) the sum of the power from the engine belas determining HVAC loads; (f) determining a proximity of engine operation to a switch point from the high efficiency mode to the less efficient mode; and (g) performing an HVAC load shutdown to reduce the HVAC loads on the motor when the HVAC load reduction allows the motor to continue operating in high efficiency mode and the compressor cycling is on.