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In the operation of vehicular air-conditioning systems, the temperature of the condenser inlet air has significant effects on system performance and operating characteristics. In some vehicles, engine cooling module (ECM) inlet air is supplied from the engine compartment, subjecting the ECM to inlet air that is hotter than the ambient environment. In addition, vehicles in idle operation are subject to ECM air recirculation that can also elevate the ECM inlet air temperature. In order to conduct development, validation, and continuous improvement testing of Heating, Ventilating, and Air-Conditioning (HVAC) systems under conditions simulating “real-life”, a condenser air pre-heating stand was built.

During the design phase of a Heating, Ventilation, and Air-Conditioning (HVAC) unit, many factors play a key role in the evaluation of system performance. However, the most decisive factors are the actual performance of each component. These components include evaporator, heater, and blower package. Any one of these components can have a dramatic impact on the overall system performance. Current performance evaluation techniques do not allow for the all-around comparison of each component. The special formulas and, respectively, special numerical values have been created for each component comparison problem. These numerical values are either Common Comparison Coefficient (CCC) for component comparison, which this paper centers on or Degree of Comparison for comparison of sealing capabilities. The comparison of test results shows significant advantages and convenience of proposed approach for components evaluation.

Vehicle defrost systems are required to defrost the windshield and side windows in a short period. This portion of the HVAC system is not only required to work without interfering with operator comfort relating to high temperatures being felt by the drivers face, but also relating to noise. Add to these restrictions the requirement that the defrost outlets used must be esthetically pleasing, and one can see how much development time is required to design an effective defrost system. Once a design is established, it must be tested. The methods currently used to test defrost performance leaves much to be desired, due to the time required to transpose actual test results into usable data. This transposition includes removing marked tracing from the windows in a cold chamber to trace paper, and then the trace paper needs to be reduced into manageable sizes of paper.