A climatic variable for constructing thermal performance lines for air-conditioned commercial buildings in Hong Kong

Abstract

The feasibility of using thermal performance lines to assess the efficiency of using energy in air-conditioned commercial buildings in Hong Kong is being explored. The paper describes a regression study aimed at identifying a suitable climatic variable that would yield linear thermal performance lines for commercial buildings in Hong Kong. The study was based on the monthly electricity consumption of 26 existing office/commercial buildings obtained from a recent survey. Candidate weather parameters considered include monthly mean outdoor temperature, outdoor air moisture content and global solar radiation, and their square and product terms. The regression analysis shows that the square of monthly mean outdoor temperature would be the most appropriate climatic variable. Explanations are also given as to why moisture content and global solar radiation were considered less appropriate, notwithstanding that in Hong Kong, the humidity is high for most of the time in the year and the cooling load due to solar heat gain is a significant component of the design cooling load of airconditioned buildings.