Performance Assessment About Building External Wall Thermal Insulation Technology In Cold Regions

The thermal insulation performance of building external wall is very poor in cold regions in our country, that lead to severe energy waste, environment pollution and poor indoor heat environment. The building external wall thermal insulation technology in cold regions is developing rapidly with the changing of energy conservation standard. But the building external wall thermal insulation technology that been widely used have some questions. There are a lot of building thermal insulation materials in material market, but the performance of thermal insulation materials have very much difference. Now some new thermal insulation materials come into material market, however there are not the thermal conductivity for calculation in thermal design code for civil building. To the thermal insulation performance and durability, Face crack, water tightness and thermal bridge of thermal insulation construction are still very difficult to solve.The thermal insulation performance and durability that been decided by thermal insulation materials and construction are the main assessment criterion. This paper categorized thermal insulation materials and analyzed the thermal insulation mechanism. The writer tested some thermal insulation material that been widely used in Xi'an in laboratory, and draw the graph of the thermal conductivity in normal temperature and humidity to the thermal conductivity in absolute dry. Finding some thermal conductivity that was provided by factory are the thermal conductivity in absolute dry and which are used in thermal calculation. This paper put forward the concept of the thermal conductivity for thermal calculation and the method that can define the thermal conductivity for thermal calculation. We must not confuse the concept of the thermal conductivity for thermal calculation and the thermal conductivity in absolute dry states, otherwise the calculation outcome is wrong. The thermal conductivity test data for XPS and EPS ball mortar that have practical significance can become the supplement ofthermal design code for civil building. The papers appraised the performance of some thermal insulation materials and give some advice about how to select thermal insulation materials.Writer summarized some usual thermal insulation construction, basing on investigating some thermal insulation projects and reading much reference material. Writer analyzed the advantages and disadvantages of the usual thermal insulation constructions. Writer carefully studied face crack , water tightness, thermal bridge of thermal insulation construction and so on and put forward concrete improvement.