Evaluation and Design of Natural Ventilation for Houses in Thailand*

Abstract

This research paper presents guidelines for evaluation and design of natural ventilation forsuburban houses in Thailand which is a part of building energy code development for residential buildings.The initial studies find that it is possible for natural ventilation to achieve thermal comfort conditions inplace of mechanical air-conditioning systems, especially in winter. The experimental research is dividedinto two parts: environmental arrangement and building opening. By measuring air conditions flowingthrough different generic types of environment, it is found that the best environment is that coveredwith large trees. Computational fluid dynamics studies on generic houses discover that cross ventilationis more effective than two-side ventilation, and is much more effective than one-side ventilation. Ingeneral, increasing the size of openings improves the effectiveness of natural ventilation. However, theoptimum effective opening area in rectangular rooms is found to be 20 percent of functional floor area.The findings from this research lead to the house evaluation method by factors of orientation and sizeof building openings. The method is successfully tested with different types of houses.