Evaporator Icing Protection Test Method

Evaporator icing is an operating state of automotive air conditioning systems in which the condensate water formed in the evaporator turns to ice. This failure mode is normally mitigated by a control system that disables the compressor when freezing temperatures are encountered. This paper reviews the causes of evaporator icing and traditional systems to protect against icing as well as tests to validate the icing protection system. A wind tunnel icing protection test is described that validates the effectiveness of the icing protection by forcing the system through the “clutch cycling transition boundary.” The proposed test requires less time to perform and is more conclusive than previous tests. Test result data is given.