A thesis submitted in pa1tial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources, and Development

Thesis (M.Eng.) - Asian Institute of Technology, 2006

In the hot and humid climate, overheating is the main problem in residential houses during summer. Air-conditioning system can solve the problem but it also consumes a large amount of energy and causes the environmental problems as well. Natural ventilation is one of a preferred solution for this issue. For the design of natural ventilation systems of the residential houses, it is necessary to have knowledge of pressure distribution in order to calculate the airflow through the opening. The experiment has been carried out with the scale model to investigate the distribution of pressure different in the model and to evaluate the use of heated stack for ventilation. For the distribution of pressure different, experimental results show that the position of the opening to the air flow direction will affect the flow through that window. It is also found that there is a strong relationship between the pressure different across the opening and the angle of air flow direction to the opening. Sixteen different configurations of window opening have been investigated on the experiment set-up. For the stack effect, investigations on the model show that the rate of ventilation increases with increase of the temperature different between inlet and outlet air and the incline of the roof. This finding is in agreement with results of the steady-state mathematical model developed for analysis of such systems. The experiment was carried out with different radiation and incline of roof. It is found that the heated stack can provide sufficient ventilation for the experiment set-up which gives the possibility of using heated stack for ventilation in real life application