A TRANSIENT HEAT AND MASS-TRANSFER MODEL OF RESIDENTIAL ATTICS USED TO SIMULATE RADIANT BARRIER RETROFITS, PART II - VALIDATION AND SIMULATIONS

A computer program was developed and used to implement the model descr ibed on Part I of this paper. The program used an iterative process to predict temperatures and heat fluxes using linear algebra principles. The results from the program were compared to experimental data colle cted during a three-year period. The model simulated different conditi ons such as variations in attic ventilation variations in attic ceilin g insulation, and different radiant barrier orientations far summer an d winter seasons. It was observed that the model predicted with an err or of-less than tell percent for most cases. This paper presents model results for nonradiant barrier cases as well as cases for radiant bar riers installed horizontally on tap of the attic floor (HRB) and for r adiant barriers stapled to the attic rafters (TRB). Savings produced b y radiant barriers and sensitivity analyses are also presented The mod el results supported the experimental trend that emissivity was the si ngle most significant parameter that affected the performance of radia nt barriers.