A Study On Thermal Processes Of Traditional Dwellings

The inside temperature environment of the traditional dwellings is mainly controlled through the passive technology which implied in the traditional architectural configuration and the constructional features. Explanation of the thermal process of these passive technologies and the thermal action are the main contents of this thesis.With the systematical analysis of the thermal environment of the traditional dwellings, and the survey and test of thermal environment of the typical north and south dwellings, based on the thermal physics, the process of convection, radiation, and phase change of the envelope of the traditional dwellings, and the thermal conduction process of the wall are discussed respectively; thermal exchange index of inner surface under different ventilation frequencies, and the outer surface thermal exchange index under different wind speed are quantitatively analysed; the thermal exchange index formula under outer long-wave radiation is given; the view that the index of average evaporation phase change of thermal exchange of outer surface is concerned with outer surface humidity, and the formula for evaporation phase change thermal exchange based on given wall temperature and the atmosphere temperature are presented. Based on the features of temperature environment of the traditional dwelling building both inside and outside, the architectural thermal process is divided into two parts: balanced and fluctuated. With stable thermal transmission theory and periodical unstable thermal transmission theory, the average inside temperature of the traditional dwelling building and its stability are analyzed respectively. Therefore the mechanism of thermal trapping, thermal insulation, and the maintenance of inside temperature environment stability in traditional dwelling buildings are theoretically explained, together with the following viewpoints:1. Due to limit of passive controlling of temperature to the inside of the traditionaldwelling, the controlling of the inside temperature can only be reached by thecombined controlling of inside building temperature and the average radiationtemperature. 2. The inside temperature of the traditional dwelling is determined by the envelope transmission and natural ventilation, of which the former includes the multiple exchange of heat of outer and inner face and the wall thermal conduction process, and is the major factor that determines the inside temperature of the traditional dwelling building; the latter is concerned with the frequency of ventilation, and affects the inside temperature with the former.3. The average inside temperature of the traditional dwelling is determined by the surface temperature of the inner wall. Its value is mainly determined by the thermal conduction of the envelope.4. Heat preservation and insulation of the envelope not only improves the average state of thermal environment inside the traditional dwelling, the more important is that, by its thermal inertia, improves the stability of thermal environment inside, and prevents extreme heat or cold.5. The idea for passive inside temperature controlling in the traditional dwelling buildings in summer should be: through natural ventilation, release the extra heat, to keep the inside temperature tolerable and, at the same time, increase the circulation speed; through shading and the improvement of thermal features of the envelope and other measures, to reduce high temperature inside the building caused by the sun radiation.6. The thermal feature of the envelope is the key factor in determining the inside thermal environment in winter, and therefore, the improvement of the thermal insulation and thermal inertia of the envelope, the airtightness, the full use of the radiation of inner thermal source and the sun, are effective measures in winter to increase the average inside temperature, and to reduce the inside temperature fluctuation.