Abstract:
This study is a survey and experimental research conducted to find ways of the thermal adaptation of the traditional northern Thai style house to suit the present topography and climate conditions. Three inventive types of building materials available locally are chosen for this research, i.e., the cement planks mixed with Miyarap Giant fiber, Lampang light-weight bricks and Mae Moh fly-ash bricks, and are compared with half-inch thick genuine wood planks, the original building materials of the northern Thai style house, for the purpose of its optimal thermal comfort. The research process consists of four steps: (1) survey the existing northern Thai style house at present; (2) examine its usability patterns, indoor space, building materials, and collect the data of both indoor and outdoor air temperature and relative humidity of five northern Thai style houses located in Chiang Kham district, Phayao; (3) explore those three inventive building materials in the northern region for testing their heat transmission coefficient (k) in a laboratory, and conduct the same testing with the original building materials of the Thai style house; and (4) compare the material properties that can affect the thermal comfort by using a computer simulation in which its setting air temperature is between 25.6 and 31.5 degree Celsius, and the relative humidity is between 62.2 and 90 percent. The result of this study shows that natural air ventilation, infiltration rate, thermal resistance value, and time lag have an influence on the comfort condition inside the northern Thai style house. Based on the computer simulation, the northern Thai style house is found to contain the thermal comfort around 30 percent all year round with the maximum comfort range in the rainy season, and the lower comfort range on average 53 percent for most of the year. This implies a certain appropriate degree of the thermal comfort of the Thai style house. Comparing those three inventive building materials in terms of their thermal comfort characteristics, the cement planks mixed with Miyarap Giant fiber has characteristics close to the half-inch thick genuine wood planks. In case of Lampang light-weight bricks and Mae Moh fly-ash bricks with no natural ventilation, both have similar characteristics which are approximately 20 to 30 percent better than the genuine wood planks. From these results, two adaptations to improve the thermal comfort are suggested. The first alternative is to reduce natural ventilation. Due to the cold weather in the study area, such reduction will bring about higher thermal comfort if used with low infiltration rate materials. Another alternative is to choose materials with high thermal resistance rate and an appropriate time lag. It is found that Mae Moh fly-ash bricks have the most suitable characteristics, followed by Lampang light-weight bricks, half-inch thick genuine wood planks, and the cement planks mixed with Miyarap Giant fiber respectively.