Abstract: An air conditioner system for automotive vehicles has an evaporator disposed in a duct and selectively operative to cool air flowing through the duct, and a combustion heater disposed outside the duct and held in air flow communication with the latter for heating air drawn into the duct. The air conditioner system thus constructed can be applied to a vehicle having a non-water-cooled engine and is effective to cause a sudden increase in the temperature of air to be supplied to the vehicle passenger compartment.

Abstract: An air conditioner system for automotive vehicles has an evaporator disposed in a duct and selectively operative to cool air flowing through the duct, and a combustion heater disposed outside the duct and held in air flow communication with the latter for heating air drawn into the duct. The air conditioner system thus constructed can be applied to a vehicle having a non-water-cooled engine and is effective to cause a sudden increase in the temperature of air to be supplied to the vehicle passenger compartment.

Abstract: A device for sensing the refrigerant level in a receiver tank and thereby detecting the surplus or shortage of the refrigerant in the tank is provided. The sensor device has a photoconductor a part of which is placed in the receiver tank. A light source is disposed at one end of the photoconductor and a light receptor element is disposed at the other end. The quantity of light passed from the light source to the receptor element through the photoconductor is changed as the photoconductor is dipped in the refrigerant in the tank. The surplus or shortage of the refrigerant in the tank is detected from the change in quantity of light received by the receptor element.

Abstract: A heat exchanger suitable for use with a combustion heater, comprises a one-piece extruded tubular heat exchanger element having a tubular body and a number of interior and exterior fins projecting integrally radially from the tubular body.

Abstract: Provided in this invention is a device for detecting overcharge of refrigerant in the cooling cycle in an air-conditioner for automobiles, featuring the provision of a sensor for detecting the liquid level in the receiver tank in the cooling cycle. Means are provided for preventing misoperation of the liquid level sensor due to the rotational speed of the compressor drive system and the transient response immediately after start of the compressor, thereby allowing correct detection of overcharge of refrigerant in the cooling cycle.

Abstract: Whether the rear seat in a passenger compartment of a motor vehicle is occupied or not is sensed and, if not, a mode door adapted to control the proportion of air flows through upper and lower outlets of an air flow duct is suitably controlled such that the amount of air blown out from the lower outlet into the passenger compartment is increased relative to that from the upper outlet which will direct the air toward the rear end of the passenger compartment. Additionally, the temperature for turning the compressor on and off are shifted to slightly higher levels compared with the temperatures at which the compressor would be turned on and off if the rear seat were occupied.