Performance Improvement Plan towards Energy-Efficient Naturally Ventilated Houses in Tropical Climate Regions

Abstract

The majority of the population in Indonesia lives in naturally ventilated and unconditioned residential buildings because they cannot afford energy services. This situation is common in many countries in tropical regions, negatively affecting the occupants’ health due to overheating. Therefore, housing types that can cool down indoor temperatures to the extent possible using a passive approach, rather than an active approach, should be developed. This study aims to improve naturally ventilated houses by considering the louver area and insulation of houses. First, we employ an on-site measurement for collecting data such as the indoor/outdoor temperature and relative humidity in an Indonesian city, Lhokseumawe. In addition, the experimental data are used to validate a numerical simulation model. Second, the numerical simulation is utilized to establish energy-efficient design solutions for houses in 14 Indonesian locations. The results show that, compared with the insulation cases, different louver areas insignificantly change indoor air conditions by approximately 0.3 to 1 °C. Additionally, the application of a combined performance improvement for both louver areas and building envelope insulation levels can reduce the indoor air temperature and relative humidity by 2.2 °C and 8%, respectively. Moreover, the daily cooling demand for the proposed improvement plan is reduced by 18.90% compared with that for the existing case. Furthermore, the annual cooling loads for the entire simulated regions are reduced by 46.63 GJ/year (23.09%). This study is a potential starting point for achieving zero-energy housing and occupants’ sufficient thermal comfort in unconditioned and naturally ventilated houses in Indonesia.