Abstract: An automobile air conditioning system supplies conditioned air to the passenger compartment of an automobile. The air conditioning system includes an evaporator for cooling the incoming flow of air and a heater core for heating the incoming air from said evaporator to a predetermined temperature. The air conditioning system also includes front and rear vent units for expelling conditioned air, and a control unit which includes a single mode selector for expelling heated air out the front vent unit and a dual mode selector for expelling heated air out both the front and rear vent units. A bypass for directly leading air from the cooling unit to the front vent unit is provided for the air conditioning system. The control unit opens the bypass when the single mode and maximum cooling mode are selected, and closes the bypass when the dual mode is selected.

Abstract: A heating system for automotive vehicles comprises a heater core utilizing engine coolant, a blower disposed upstream of the heater core, and a closed-loop pipe heating system utilizing exhaust heat from exhaust gas. The pipe heating system comprises an evaporator section disposed in an exhaust gas passage, a condenser section disposed downstream of the heater core, a pipe section defining a first fluid passage from the evaporator section to the condenser section, a return pipe section defining a second fluid passage from the condenser section to the evaporator section, working fluid circulating in a fluid passage defined in the evaporator section and condenser section, and in the first and second fluid passages, sensors for monitoring whether activation of the pipe heating system is required, and flow control means disposed in the return pipe section, for controlling working fluid flow from the condenser section to the evaporator section, in response to signals from the sensors.