SD-95-16-2 -- Energy Consumption Testing of Innovative Refrigerator-Freezers PDF

The high ambient temperature of the Canadian Standards Association (CSA) and the AHAM/DOE Refrigerator-Freezer Energy Consumption Standards is intended to compensate for the lack of door openings and other heat loads. Recently published results by Meier and Jansky (1993) indicate labelled consumption overpredicting typical field consumption by 15%. In-house field studies on conventional models showed labelled consumption overpredicting by about 22%. The Refrigerator-freezer Technology Assessment (RFTA) test was developed to more accurately predict field consumption. This test has ambient temperature and humidity, door openings, and condensation control set at levels intended to typify Canadian household conditions. It also assesses consumption at exactly defined compartment rating temperatures. Ten conventional and energy-efficient production models were laboratory tested. The RFTA results were about 30% lower than labelled. Similarly, the four innovative refrigerator-freezer models, when field tested, also had an average of 30% lower consumption than labelled. Thus, the results of the limited testing suggest that the RFTA test may be a more accurate prediction of field use. Further testing with a larger sample is recommended. Experimental results also indicated that some innovative models could save up to 50% of the energy consumption compared with similar conventional units. The technologies that contributed to this performance included dual compressors, more efficient compressors and fan motors, off-state refrigerant control valve, fuzzy logic control, and thicker insulation. The larger savings were on limited production models, for which additional production engineering is required for full marketability.

KEYWORDS: year 1995, energy consumption, testing, innovating, refrigerators, freezers, refrigeration, energy conservation, accuracy, calculating, ambient temperature, humidity, condensation, Canada, domestic, laboratory testing, site testing, performance