Patent ID: 8161770

Claim:
A vehicle air conditioning system comprising: a compressor; and an external heat exchanger which exchanges heat between external air and a coolant discharged from the compressor, the coolant whose heat is exchanged in the external heat exchanger being divided among not less than two parallel branch paths, each of evaporators connected to a separate one of the branch paths, masses of coolant which are evaporated by the evaporators becoming confluent coolant in a merging part, and the confluent coolant being supplied to the compressor, wherein an inlet side of each of the evaporators includes a decompression device, inlet side coolant of each of the decompression devices is configured to exchange heat with outlet side coolant of a separate one of the evaporators, respectively, wherein a first branch path is connected to one of the evaporators in a front part of a compartment, and a second branch path extends toward a rear of the vehicle and connects to one of the evaporators in a rear part of the compartment, wherein parts, in which the inlet side coolant of each of the decompression devices connects to each of the first and second branch paths coolant and exchanges heat with the outlet side coolant of each of the evaporators, respectively, are formed of tubular heat exchangers, and wherein in the tubular heat exchangers, a rate of heat exchange per unit length of the tubular heat exchanger in the second branch path is set smaller than that of the tubular heat exchanger in the first branch path.