Air-conditioning device for hybrid vehicle

Abstract

An air-conditioning device includes a control system for saving fuel consumed to drive the device and for enhancing comfortability of passengers at the same time. The air-conditioning device is operated under a cooling mode emphasizing comfortability or under an economy mode emphasizing fuel economy. Under the cooling mode, the device is controlled in a lower temperature range. Under the economy mode, the device is controlled in an intermediate temperature range to secure comfortability when cooling-down is required, and in a higher temperature range to save fuel after the cooling-down has been completed. Information on vehicle speed may be used in the control under the economy mode. The device may be turned off or controlled in a higher temperature range to save fuel, especially when the vehicle comes to a halt. Frost on a windshield which develops when the vehicle is at a halt for a certain period without operating air-conditioning device is avoided by operating the device at a lower temperature, only when such condition exists. Such condition may be detected by a humidity sensor installed in the passenger compartment.