Improvement of Thermal Comfort in Buildings through Passive Design

Abstract: In hot humid regions the high outdoor temperature has negative effects on the indoor temperature of buildings that are not designed to cope with the local climate. This leads to discomfort for the occupants. In Maputo City, the capital of Mozambique, electrical devices such as fans and air conditioners are used to obtain a comfortable indoor climate. The cost of electricity is a problem for consumers who have low incomes. Therefore, many cannot afford to pay their electricity bills, leading to conflict with supply company. In the developing countries, the main use of energy is for lighting, cooling, heating and appliances used in buildings. Approximately 50% of the electricity used in Mozambican buildings is used to produce an artificial indoor climate, by heating, cooling, ventilation and lighting. If building designs were improved taking into account the local climatic and environmental conditions, as well as material specifications, significant gains would be achieved in terms of energy efficiency. This would reduce the need for retrofitting to achieve a comfortable indoor climate. The use of passive strategies to reduce the use of electricity to achieve thermal comfort does not significantly increase the final cost of ordinary buildings, and these strategies require little or no maintenance. The research described in this thesis deals with strategies for passive design and its contribution to minimising the problem of poor indoor climates. Through a literature review, the state of the art regarding passive strategies was assessed, the knowledge gap in this field was determined, and the tools suitable for carrying out these studies were identified. By means of simulations, the results of simulations demonstrated that thermal comfort in buildings could be significantly improved by using existing and proposed strategies for passive design. No electricity would be required for electrical devices as the indoor environment would be sufficiently comfortable. Apart from building orientation, other strategies for passive design could be applied to existing or new buildings, at a low cost and without affecting the aesthetics of the buildings too much. Passive design strategies also could be applied to existing buildings that are not optimally oriented, but at a slightly higher cost than that associated with buildings with an optimum orientation.