Empirical Research On Improving Indoor Thermal Comfort By Use Of Solar Energy In The High-altitude Cold Region

High-altitude cold region in western China, a typical type of building climate zone, is located in the eastern edge of the China's Qinghai-Tibet Plateau. Here having high altitude and cold climate is not suitable for human survival under natural conditions. Therefore, improving the habitation environment and increasing the indoor temperature during winter have been one of the important aspects of human survival and development. The Chinese government has established comparatively good heating systems in urban areas and provided urban citizens with heating subsidies, but the heating needs of rural citizens have not been included in the scope of the government's public expenditure. Observation data show that the average indoor temperatures of three villages are between 6 to 11℃in Lintan,Gansu province,which are lower than the national minimum standard of indoor temperature of 14 degrees and are far apart from 16 degrees of comparatively well-off level. It reflects lower heating assurance of local residents.In the last 30 years, the Chinese economy has developed rapidly, which has led to great improvements in the living standards of urban and rural residents. However, energy shortages still exist, especially with respect to household heating.Longer heating period and lower temperature make local greater energy demands. Since long domestic energy demand here has mainly depend on firewood, crop straw, livestock manure and other biomass-based energy. Survey results show that the heating energy consumption is all years of 2572.26kgce per settle and 488.36kgce per capita in three villages, which is equivalent to China's rural per capita living energy consumption (490.4 kgce). The massive consumption of biomass energy has affected the survival of vegetation. Its seriously degradation has been due to the short growing season of plants and the low production of grass. It is always important to maintain water and conserve soil here the upper reaches of Yangtze River and Yellow River. Therefore a big contradiction has come into being between residential energy demand and ecological protection. The project of wildwood protection was implemented by Chinese government in 1999. At the same time, measures such as soil and water conservation, small watershed management and returning farmland to forest have been employed in the region to restore the local vegetation. The amount of resources required to implement these measures was extremely large, but their effects have been limited. One reason for these limited effects has been a shortage of rural household energy, which has made it difficult to protect vegetation effectively.But there are good prospects for the development and utilization of new energy thanks to abundant solar energy resources. Based on the observation test and heat balance principle, every square of attached sunspace can saved 8.5 kilograms of standard coal equivalent per year. Although the increase heat of local attached sunspace is lower than the national technical standard, promoting attached sunspace has enormous social and economic benefits according to local rural energy consumption investigation and it's economic and environment cost estimation results. It is worth scale popularization.30 years can recover the investment cost through the recovery of investment estimation.However, it is discovered by investigates that a small utilizing proportion of attached sunspace building and less energy conservation are here due to economic, technical, policy and other reasons, especially the substitution costs. Only 13.1% rural resident use attached space. 8.72% farmer houses constructed below 10 years have attached space.4.38% farmer houses constructed 10-30 years ago have attached space. None of farmer houses constructed above 30 years have attached space. Because of poverty and low education level of local resident, the huge economic benefits of energy conservation by applying attached sunspace can not be achieved relying solely on spontaneous reconstruction of households. Similarly, because of financial difficulties of local government, no incentive and preferential policies for attached sunspace building reconstruction are lay down until now. Therefore, it is hard for promoting attached sunspace building reconstruction in the high-altitude cold region.Some useful references are proposed here to resolve local heating problems. First, construction technology must be normative to improve thermal performance of local attached sunspace. Second, the best way of heating should be selected to optimize indoor thermal effect. Finally, increasing financial support is essential to attached sunspace construction of rural houses. Such an overall consideration of heating problems in the high-altitude cold region will make it possible to meet rural resident demands of indoor thermal comfort and reduce the consumption of fossil energy.