Effect of Radiant Barrier Technology on Summer Attic Heat Load in South Texas

Abstract

The objective of the study was to experimentally evaluate the performance of radiant barriers in single-family occupied housing units in South Texas. Ceiling heat fluxes, attic air temperatures, indoor air temperatures, ambient air temperatures. roof temperatures, and solar radiation were measured. Results of the radiant barrier experiment using two side-by-side 600 ft2 units are presented. Attic fiberglass insulation of nominal R-11 was installed in the two apartments when the units were last remodeled in 1974. The test houses responded similarly to weather variations, that is, attic temperature and heat flux profiles were similar in magnitude prior to the retrofit. Residents of the housing units were asked to set the thermostats at 76°F. Data were analyzed for periods of time which had the greatest attic temperatures (11 a.m. - 11 p.m.) and for which the indoor temperature differences were less than 1 percent. The results showed that radiant barriers reduced ceiling heat loads (on daily basis) by an average of 60 percent.