3279 -- Approximate Attic Air Temperatures and Ceiling Heat Fluxes with Radiant Barriers PDF

This paper presents the results of a simplified analysis for determining heat transfer through a ceiling for ventilated attics, using different barrier placement and different ceiling insulation thicknesses for both winter and sumrner conditions. Results of the analysis compare favorably with the measured ceiling heat fluxes of three experimental studies. The study was made to determine, approximately, the heat transfer effect of attic radiant barrier systems, specifically the effects of barrier placement on ceiling heat flux, which represents the cooling load on the conditioned space from the attic. The study was performed considering the effects of different insulation R values and considering airflows. The simplified analyses developed can be applied to other attic systems. The investigation identified the parameters of significance needed to relate the results to experimental data. Specific results include steady-state heat gain calculations and attic air temperatures.