CH-95-08-2 (RP-713) -- Summary and Comparison of Methods to Calculate Solar Heat Gain PDF

Examines and compares methods used to calculate the solar gain of windows. Pays particular attention to the public-domain computer programs VISION3 and WINDOW 4.1. Presents calculated results to quantify the sensitivity of solar heat gain with respect to a wide range of glazing system design parameters and operating conditions. Examines and discusses details concerning solar optical properties and heat transfer mechanisms. Concludes that solar gain is most sensitive to the solar optical properties of the glazing - the most important property being the transmittance of the outdoor glazing. Variables that directly affect heat transfer rates (fill gas type, convective heat transfer coefficients) have a significantly smaller effect.

KEYWORDS: year 1995, Calculating, comparing, solar heat gain, heat gain, windows, USA, Canada, computer programs, glazing, heat flow, glass