Development of Climate Indices Using Local Weather Data for Shading Design

Abstract

The energy performance of buildings depends on how effectively the building envelope responds to climate. Architects, therefore, need to design building envelopes with the consideration of local climate characteristics in the early design stage. Simplified formulas were used that evaluate the heating and cooling energy demand of building envelopes, which were applied to a model building with envelope and climate properties according to eight climate zones. Two climate indices, P and S, were developed. P enables the comparison of the heating and cooling energy demand of building envelopes, and S is for comparing the solar heat gain during heating and cooling seasons to review the feasibility of installing shading devices. The physical properties of envelopes were set differently according to the requirements in each climate zone proposed by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 90.1. Using local climate data, the P and S of 24 cities over eight climate zones in the United States were derived, which can be used to evaluate the heating and cooling energy characteristics of envelopes. The indices not only enable users to understand the characteristics of the local climate conditions in a simple manner, but also to carry out quantitative assessments on whether shading devices are feasible and, if so, what type is recommended.