ABSTRACT

Energy efficiency of air-conditioned buildings is important for urban cities in hot climate, like Hong Kong.  This thesis examines the problems of building energy performance and establishes systematic methods for its analysis and assessment in air-conditioned buildings.

Worldwide building energy standards have been studied and evaluated to identify salient features and useful experience.  It is found that the advanced countries are moving towards performance-based standards while many developing countries are designing new energy standards using a prescriptive approach, such as Overall Thermal Transfer Value (OTTV).

The climatic conditions of Hong Kong have been investigated.  Essential outdoor design conditions have been developed and the climatic properties have been analysed using statistical and graphical methods.  To facilitate building energy analysis, typical year methods have been examined and a weather database for building energy analysis has been developed for Hong Kong.  It is found that the typical year approach cannot ensure the simulated building energy performance is the closest to the long term.  The degree of uncertainty of the typical years has been quantified and multi-year simulation has been suggested as a viable alternative.

To study building energy simulation methods, a base case office building model has been developed on the DOE-2 and BLAST simulation programs.  Sensitivity analysis has been carried out to examine the important design parameters; regression analysis has been performed to develop energy equations for Hong Kong.  It is found that the OTTV form of equation relates quite well to the energy consumption and the solar component is predominant in the OTTV standards.  To enhance generation of regression models, a method using randomised input has been proposed and tested.  A general form of energy equations has also been developed to help relate building energy performance to various design parameters.