Search Results

CO2 is an alternative to replace the conventional refrigerant (R134a) for the air-conditioning system, due to the high Global Warming Potential (GWP) of R134a. There are concerns with the use of CO2 as a refrigerant due to health risks associated with exposure to CO2, if the concentration of CO2 is over the acceptable threshold. For applications with CO2 as the refrigerant, the risk of CO2 exposure is increased due to the possibility of CO2 leakage into the cabin through the duct system; this CO2 is in addition to the CO2 generated from the respiration of the occupants. The initiation of the leak could be due to a crash event or a malfunction of the refrigerant system. In an automobile, where the interior cabin is a closed volume (with minimal venting), the increase in concentration can be detrimental to the customer but is hard to detect.

Load maps show the relative frequency of ambient temperatures and driving states divided in several classes. They are a means to determine the yearly average of performance or power consumption of an automotive air-conditioning system. The load maps for California, Central and Southern Europe are used to illustrate the differences in power consumption. The possible power savings using an evaporator control concept are discussed and assessed as an example for an new technique which has low effect at high load but large impact at part load conditions.