A SIMPLIFIED BUILDING LOAD AND ENERGY ANALYSIS METHOD

Abstract

Minimizing air conditioning energy consumption has become an important factor in the design of buildings and air conditioning systems. Computer programs are being used to analyse the effects of different parameters in building energy consumption. But such programs necessitate extensive efforts in setting up weather data and specifying input variables. This study analysed the characteristics of the DOE-2.1A computer program suite and proposed a new approach for manual calculation of building annual air conditioning load and energy consumption. A manual calculation procedure was then developed based on simple heat transfer equations. The corresponding load factors were determined from the DOE-2.1A output by regression analysis. In the manual procedure the annual cooling load of a building is to be determined based on its load components - walls, roofs, windows, internal heat sources, and amount of outdoor air. The air conditioning energy consumption can then be calculated by using an average plant coefficient of performance value. The methodology and equations used are similar to that of the ASHRAE peak load calculation procedure, both requiring similar sets of building thermal data as input parameters. Therefore in the process of air conditioning peak load calculation, it requires only minimal extra effort to compute the annual cooling load and energy consumption for building and plant analysis. Validation of the proposed method was carried out by the DOE-2.1A simulation of a reference building and the deviation was found to be within 3.7%. Finally, recommendations were made to further enhance the procedure as an energy audit standard.