Energy simulation for a typical small office building in Indonesia

Energy demand for buildings become a crucial problem in Indonesia, as there is huge construction activity in Indonesia. It requires a fundamental investigation on how to minimize the energy consumption, because air conditioning in Indonesia takes more than 45% of the total consumption of the building electricity. In this paper, the results of simulating the cooling energy demand of a small reference office building using the weather data of Surabaya, Indonesia is presented. The simulation and visualization tool used was Design Builder, an Energy Plus based dynamic thermal simulation engine. First of all, a highly insulated reference office building was simulated, in order to obtain its cooling energy demand. Subsequently a sensitivity analysis was done with the aim of obtaining the parameters that contribute significantly to the decrease of cooling energy demand. The results show that increasing the indoor air set point temperature gives the most valuable effect of the cooling energy demand, followed by the variation of percentage of north window to wall ratio and g-value of glass. In addition, north shading device also contribute to the reduction of cooling energy, followed by overhangs. Thermal mass, the ratio of window to wall for south and east orientation, U-value of glass, and south shading give only little effect on the percentage change of cooling energy. By simulating an optimized building based on previous simulation results, the cooling energy demand decreases 40% compared to the base case.