A method and apparatus controls a recirculation position of a return vent in an HVAC system for a vehicle with a compressor driven by a start/stop engine. A partial recirculation position is set according to a basic recirculation strategy while the engine is operating. An auto stop event is entered at a time with the compressor operating. A full recirculation position is set during the stop event by an HVAC controller if a plurality of low fogging probability indicators are true. The low fogging probability indicators include a sensed ambient temperature being above a predetermined temperature, a sensed state of a windshield wiper being an off state, and a sensed sunload being above a predetermined sunload. The return vent is set at other than the full recirculation position by the HVAC controller according to the basic recirculation strategy if the low fogging probability indicators are not true.
Vehicular HVAC system with modified air recirculation for start-stop engine
2017-05-23
Patent
Electronic Resource
English
IPC: | F25B Kältemaschinen, Kälteanlagen oder Kälteverfahren , REFRIGERATION MACHINES, PLANTS, OR SYSTEMS / B60H ARRANGEMENTS OR ADAPTATIONS OF HEATING, COOLING, VENTILATING, OR OTHER AIR-TREATING DEVICES SPECIALLY FOR PASSENGER OR GOODS SPACES OF VEHICLES , Anordnung oder Einbau der Heizung, Kühlung, Lüftung oder anderer Luftbehandlungsvorrichtungen für die Fahrzeugräume für Reisende oder Fracht |
Equipment and system for supporting HVAC by using vehicle engine stop / start
European Patent Office | 2020
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