Heat load calculation and analysis for commercial building air conditioning system

Abstract

Air conditioning system consume more than 50% of total commercial building energy consumption such as hotel, office, shopping mall and hospital in Malaysia. Solar heat through fenestration particularly on vertical surfaces play as major role in determining the thermal performance of a building. Maximum solar heat gain factors (SHGFs) has been used to estimate the peak heat load. This project describes the procedure of peak heat load calculation by using overall thermal transfer value (OTTV) and hourly analysis program (HAP) to obtain the heat load profile. A 33 story hotel building layout and envelope is being used and further optimization on the building envelope configuration has been done to observe the result. This research have showed how building envelop configuration affect the building cooling load requirement and apply in decision making base on the return of investment (ROI). The hourly analysis program result have showed that hotel air conditioning system operated at 80% or higher cooling capacity (Peak load) only during 1pm to 3pm and most of the time plant room is operate at Part Load condition. Plant room energy consumption and return of investment (ROI) analysis help in decision making on the particular building envelope configuration. The result showed that ROI period increase with the quantity of double glazed with low-E glass applied in hotel envelope and it is more cost effective if this type of glass is being apply at non shaded external surface. This study also carry out ROI evaluation and comparison for the plant room that with and without variable speed drive (VSD), the result showed that VSD plant room only take around 2 years to get the return of the initial investment cost.