An air conditioning reactor is provided for producing high temperature, high pressure refrigerant in an engine driven air conditioning system. The system derives power from the waste heat from the coolant of an exothermic engine. The reactor has a double chamber construction which includes an inner chamber and outer chamber. Low temperature refrigerant vapor flows into the inner chamber while high temperature coolant flows into the outer chamber and around the exterior of the inner chamber, thereby raising the temperature and pressure of the refrigerant inside the inner chamber, and causing release of high pressure, high temperature refrigerant out of the inner chamber of the reactor. The reactor can therefore eliminate the need for a compressor in an air conditioning system by utilizing the waste heat in the coolant flowing out of a thermal combustion engine to produce high pressure, high temperature vapor. The reactor can also operate having a reactor chamber internal an engine or engine housing wherein the pressure and temperature of the refrigerant in the reactor chamber is raised by the transfer of energy from the high temperature engine.