Automotive Science and Engineering

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Adjustable throat-area expansion valves (ATAEV) are functioned as area regulator control units. In literatures, there are many expansion valves normally used in automotive air-conditioning systems, as regulator and electrical type valves. Nevertheless, a review study for such issue has not been introduced, according to the best of author knowledge. The present paper presents a review study for expansion valves used in air conditioning of automobiles. Different types of expansion valves are discussed including the working principles and the limitation of their working conditions.