Edwards, T., "The Rovac Automotive Air Conditioning System," SAE Technical Paper 750403, 1975, doi:10.4271/750403.
The ROVAC air conditioning system, a new system that employs air as the refrigerant, is a combination rotary compressor/expander unit. A prototype has been modeled, designed, fabricated, laboratory tested, and field tested in a full size four door 1973 Dodge Coronet. The description of the new system, the analysis, design and actual test results are reported here.The objective of the engineering program was to demonstrate and prove the capability of the ROVAC system to effectively and efficiently air condition automobiles. The prototype system installed in the Dodge Coronet produces delivered cooling capacity on the order of one to one and a half tons per thousand rpm and has produced delivered coefficients of performance at relatively high humidity levels (150-180 grains water per pound of dry air) rivaling the best developed conventional vapor compression air conditioning systems.While the present system reported herein has not reached the levels of performance predicted by detailed computer models, continued hardware improvement is facilitating actual performance very near the levels predicted to be practically achievable.During actual in-car jury tests, the prototype ROVAC air conditioning system brings the average passenger compartment temperature from a thermally soaked condition of 107°F down to 72°F in less than two min with five passengers at an average road speed of 30 mph.