Economic Evaluation of Insulation/Radiant Barrier Systems for the State of Texas

Abstract

This paper presents simulated performance of insulation/radiant barrier systems under different Texas climates. A transient heat and mass transfer model which predicts thermal performance of residential attics (Medina, 1992) was coupled with an "economic" subroutine. Simple payback periods were estimated which were based on current insulation and radiant barrier (RB) prices (materials and installation), and current and forecast electric rates. It was found that when the analyses were based solely on reductions of ceiling heat loads during the summer time, a combination of R-11 with RB was more effective than upgrading the insulation level to R-19. Similarly, adding a radiant barrier to an existing insulation level of R-19 proved more effective than upgrading to R-30. When heat gains to the cold air traveling inside A/C ducts (\which are usually installed in attic spaces) were considered, all insulation/radiant barrier combinations showed faster payback periods than insulation upgrades, During the winter time, insulation upgrades proved to be more effective than insulation/radiant barrier combinations. The simple payback analyses presented herein include both summer and winter simulations.