Patent ID: 7861547
Filing Date: 2011-01-04
Classification: B60H

Abstract:
1. A method of operating a HVAC system in a vehicle having an engine that operates in a high efficiency mode and a less efficient mode, the method comprising the steps of: (a) operating a refrigerant compressor to cool a passenger compartment and charge a cold thermal storage apparatus; (b) determining if a cold charge in the cold thermal storage apparatus has exceeded a predetermined threshold; (c) enabling compressor cycling if the cold charge in the cold thermal storage apparatus has exceeded the predetermined threshold; (d) detecting if the engine is operating in the high efficiency mode; (e) determining an amount of HVAC loads on the engine; (f) determining a proximity of the engine operation to a switching point from the high efficiency mode to the less efficient mode; and (g) conducting a HVAC load shed to reduce the HVAC loads on the engine if the HVAC load reduction allows the engine operation to stay below the switching point for the high efficiency mode and the compressor cycling is enabled.