Research On Indoor Thermal And Humidity Environment And Simulation Of Improvement Measures For Prefab Houses

Prefab houses play a tremendous role in disaster relief and construction site, but as the temporary buildings, due to their own structural characteristics: the convenient of installation and transportation, because of small thermal resistance and thermal inertia , the thermal environment in prefab houses is poor. It is hot and stuffy in summer, but cold in winter. Therefore, it is important for us to carry out research on internal environment and improvement measures of prefab houses.The paper first summary the basic theories on general constructions, then analyze the influence factors related to human thermal comfort ,impact of thermal and humidity environment in prefab houses, based on the heat transfer theory between prefab houses and outdoor environment, author collect temperature, humidity and other relevant parameters in disaster relief and construction site in summer and winter, The results indicate that both indoor temperature and wall surface temperatures of prefab houses are high: The maximum indoor temperature reaches up to 36℃, and the surface temperature reaches up to 50℃; and indoor relative humidity is high, now occupants are at the risk of heat stroke and heat fatigue. The environment is also poor in winter, due to cold radiation at night, the internal temperature of prefab houses and the outdoor temperature were basically the same, and sometimes even lower than the outdoor temperature, coldhouse effect existed. And the large temperature difference between day and night made more uncomfortable.The research group investigated the health of occupants of the prefab houses, and results showed that hot and humid environment would make residents reduce food intake, the incidence rate increase, mental state deteriorate.There were lots of problems,such as hot in summer, cold in winter, mosquitoes,etc. So indoor environment have to be studied and improved.The fluent software was used to simulate the internal temperature distribution of closed and open prefab houses in summer, with heat source and without of prefab houses in winter. And we reached conclusions: Temperature of closed prefab houses were obviously superior to open in summer, and it was low in winter, but it was higher in prefab houses with heat source.At the end of this article, the paper carried out some experimental researches on some simple improvements for prefab houses. And the main conclusion followed:The envelope of prefab houses is an important factor affecting indoor environment, through changing the envelope material, thickness, orientation selection, window to wall ratio and other factors, the indoor thermal environment was improved; in the summer, natural ventilation or mechanical ventilation, the installation of ceiling and other methods can improve thermal and humidity environment of prefab houses, besides we should pay attention to the use of shade;In winter, we can take advantage of solar radiation during the day and other measures to increase the heat-got , to reduce infiltration of cold radiation. It can be very good for comfort and to reduce the residents to increase the heat source ect.