Impacts of advanced refrigerator insulation

Recent developments in advanced insulations, such as powders under a soft vacuum (R = 20 per inch), and hard-vacuum insulation with spacers (R = 15 per 0.1 inch), merit evaluating their practical uses. Refrigerator/freezers (R/Fs) are well-suited for incorporating the new insulations for the following reasons: the energy consumption of R/Fs must be reduced to comply with the National Appliance Energy Conservation Act (NAECA) standards; the Montreal Protocol to Control Ozone-Depleting Substances calls for a reduction in chlorofluorocarbons (CFCs) that are now used in the insulative foams in R/F sidewalls; and both high R-values to minimize heat gain through the walls, and thin walls to maximize the interior volume, are desirable. We selected two different R/F base-cases for this analysis; one had the typically used CFC foam (R = 7.7 per inch), while the other featured non-CFC foam (R = 5.3 per inch) in the exterior walls and doors. (In keeping with industry practice, both refrigerator doors were insulated with fiberglass.) Two simulated modifications of both of the base cases, based on the DOE closed-door test, included replacing part of the wall and door insulation with either 1 inch of powder or a 0.1 inch layer of hard vacuum/spacer insulation.more » Both of these modifications met the standard, even when the non-CFC foam base case was simulated. 13 refs., 5 figs.« less