A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering

Thesis (M.Eng.) - Asian Institute of Technology, 1995

Knowledge and understanding of heat transfer through a roof to an air-conditioned building have become a necessity in the importance aspect of providing comfort to human being as well as for the ration use of energy that means benefiting both individual building owners and the national economy. The mechanism of heat transfer is a dynamic phenomenon influenced by many factors such as instantaneous solar radiation intensity, the thermal properties of materials, interior and ambient temperature. For the most part of the world heat transfer coefficient recommended by ASHRAE is adequate to use. But this figure will have more accuracy if the experimental study is set up for the case of a country with low wind speed. Two types of the roof, the tilted and flat roof made from CPAC Monia tiles and cellocrate sheet respectively, are used to test with the variations of radiant barrier TYVEK, glass wool and gypsum board in the case of over purlin, under roof truss or as flat ceiling configurations under no ventilation or ventilation condition in the working hours. Heat flux and temperature results are given in graphical and tubular forms. The configuration of radiant barrier as flat ceiling is the best configuration among over purlin or under roof truss not only no ventilation but also ventilation. Radiant barrier as flat ceiling under ventilation is the best among other types of testing insulation material either under ventilation or no ventilation for the tilted roof. Radiant barrier as flat ceiling under no ventilation is the best among other types of testing insulation material under no ventilation for the flat roof. The simulation model using the finite different method program shows qualitative well prediction for heat flux through roof compared with using the heat flux meter while temperature prediction using model is fair compared with using thermocouples and the heat flux meter. This may come from time lagging of measurement using the heat flux meter and the accuracy of the data logger and the multiplexer due to rainfall coming to the experiment room.