Study On Extant Buildings Energy-Conservation Transformation And Assessment Of Energy Consumption In Cold Area

A large amount of extant buildings in China wasted high energy and poor insulated performance of building envelope. Thus it's of great significance for buildings energy-conservation working, environmental protection and sustainable development that optimization plan of energy-conservation transformation and energy efficiency rating assessment system is studied according to existing building's character.Based on extant buildings energy-conservation transformation in cold area and a series of thorough and careful investigation and study, by the methods of on-site tests and the computer simulation, according to climatic character, building energy consumption and different character on winter, summer and transition season, transformation plan about the building envelope suit for Xi'an were summarized and analyzed in the paper. Then, extant building energy-conservation transformation demonstrative project in Xi'an which managed by Xi'an Municipal Construction Committee in 2007 year is as an example and dynamic simulated by DeST-c simulation software, building energy conservation effect influenced by the different transformation plan of the envelope structure and thickness of insulations system is analyzed, and the best thickness of insulations system is calculated, economic efficiency and investment recoupment period of transformation plan is analyzed, at last the best energy conservation transformation plan for extent building envelope structure in Xi'an is bring forward.Hospital floor of Xi'an second hospital is as a example, heat transfer coefficient of building envelope is measured on site before and after transformation, aimed at the question that in non-heating period it will take large error by heat flow meter method. the modifying error method is raised, and measure error is reduced to 5.5%.The thermal defects of demonstration building envelope is measured and analyzed before and after transformation, and quantity index of building cost heat and heating cost coal is calculated according to energy-conservation design standards. Not performance index comparing method is used for evaluating extent building energy-conservation transformation effect, but computer simulation is used by setting up DeST-c model and simulating whole year loads of building for synthesis evaluating energy-conservation effect before and after transformation, and rationality and economy-applicability of transformation scheme is proved. The theoretic according and project application method is afforded for developing extant building energy-conservation transformation in cold area and assessment of energy consumption.