Thermal efficient dwelling design, Bali, Indonesia
In the warm humid tropical climate of Bali, Indonesia, overheating and high humidity influence occupants' comfort, indoor climate and the comfort of their homes, both directly and indirectly. The traditional way to deal with these problems, using natural ventilation, was ecologically sound and acceptable. However, development of tourism in Bali has had a positive impact on people's earning, causing cultural pressure, migration and a rapid rise in the urban population, as well as increasing housing demand. In urban areas, the methods of climate modification have moved away from natural ventilation, and comfort is now more often achieved by installing air conditioning. This has caused increasing energy use and had economic impact. As world-wide energy consumption will continue to increase, the use of more energy will have more impact on global warming. In these circumstances, energy efficiency is paramount, particularly in the dwelling designs for new housing development in Indonesia. The study focuses on the design of a thermally comfortable dwelling in the warm humid climate of Bali, Indonesia, with emphasis on the energy efficiency of the naturally ventilated and air-conditioned dwelling. Using a computer program and energy conservation strategies, a dwelling design was simulated. A model dwelling was adopted from a standard house type for people on a middle class income, based on the family size of a couple with two children. Such units are built by the National Housing Authority of Indonesia. A comprehensive study of the computer-simulation outcomes, survey research, previous works undertaken and literature reviews were carried out, to develop a thermally comfortable dwelling design. This new thermally efficient dwelling design was simulated to draw the final conclusions of the research. The research discovered that the combination of both natural ventilation and air conditioning, integrated with the combined design of a compound-compact dwelling, are an intelligent response to the thermal comfort performance problems of a dwelling in the warm humid climate and architecturally adaptable to the culture of Bali. The study found that a combination of natural ventilation with air conditioning which is only used when necessary, coupled with insulation and shading devices, can significantly reduce energy consumption and achieve adequate thermal comfort. In this respect, however, architectural design should come first, and be considered before an engineering solution. The reasons are that architectural solutions are more robust, and has a long duration of applicability, while the technology is perhaps the opposite, being prone to mechanical failure. When a less compact dwelling is designed, increased use of natural ventilation can be achieved. The use of airtight construction, insulation in the building envelope and shading devices are effective ways of reducing the air-conditioning load.