Reduction of Cooling Energy for Highly Glazed Buildings in Malaysia through Scheduled Start-up and Shutdown of Air-Conditioners

The aesthetic of buildings through overly used of glazing in hot and humid countries like Malaysia is often penalized by the high energy cost to operate the air-conditioning system due to high heat gain from the solar radiation. With the present and future uncertainties in the cost and availability of energy, a study should be performed on how to reduce energy consumptions in the operations of air-conditioning system. In the present work, reduction of cooling energy in highly glazed academic buildings in a university is studied by scheduling the start-up and shutdown time of the air-conditioning system according to the sun position. The start-up of air-handling units (AHU) for areas of the buildings that receive late sun radiation is delayed. On the other hand, the shutdown of AHU is scheduled earlier than the time when the offices are vacated at the end of the working day in order to benefit from the transient period before the areas become uncomfortable. The study is done by computer simulation using EnergyPlus software. The cooling energy of selected building or areas as a result of each of the proposed strategy is analyzed. It is found from the present study that the present strategy has a significant potential for savings in the cooling energy of the buildings.