Impacts of building envelope design factors upon energy loads and their optimization in US standard climate zones using experimental design

Abstract

The impacts of building envelope design factors upon cooling and heating loads in US cities of different climate zones were quantitatively analyzed using a fractional factorial experimental design. This analysis yielded regression models of the energy loads as functions of the factors considered. The relative importance of building envelope design factors for an office building was statistically compared. The design factors were classified into three groups: (1) a factor directly affected by insolation, SHGC; (2) another group affecting heat transmission based upon the temperature difference between the indoors and the outdoors, WDI, WI, and ACR; and (3) another group affecting the effective area for heat transfer, WWR, AR, FA, CH, and PH. Unique phenomena in different climate zones were further investigated considering the weather features in those zones. Pareto-front curves of cooling and heating loads were obtained, yielding information on optimal design factor sets in the different climate zones. The reasons for the variation in optimal sets of design factors along the Pareto fronts are explicitly explained in terms of the main effects and interaction effects of the design factors.