Southern California Edison Supermarket Refrigeration Report

Southern California Edison's Refrigeration Technology and Test Center conducted tests with open refrigeration display cases and concluded that aluminum thermal shields reduced energy use and lowered operating costs, allowing supermarkets to increase their profits.

Refrigeration load was reduced by 8.5% with night use of thermal shields, and by 41% when the shields were closed for the day. The compressor power of the refrigeration unit was reduced by 9% when the case covers were closed for six hours, and by 36% when they were closed for 24 hours.

Use of thermal shields lowered the average product temperature by 5° F on the bottom shelf of the display case, and by 3° F on the upper shelf. Products remained at these cooler temperatures for up to 15 hours after the case covers were opened.

The temperature of the air discharged during the defrost cycle was much lower also, indicating that thermal shields maintained stable product temperatures. The amount of heat sent to the condenser decreased by 7.4% during night use, and 38.7% after holiday use, suggesting that when new equipment is purchased for new construction or renovations, the size of condenser units can be reduced if thermal shields are used regularly.