Theoretical Analysis And Model Test Of External Shading Blinds In Tianjin

The application and research of external shading system of building is extensively paid attention to in south china . Along with temperature rising in cold area,it's as hot as in south china, but it's adverse for energy saving that we don't attach adequate importance to external shading in cold area. External shading devices are correlative with regional and climatic characteristic so we can't copy the devices in south fully.We should not only take the shading into take into account but also the obtaining solar radiation in winter .This thesis bases on the climatic characteristic of cold area where tianjin sits and study the external shading theory . It focuses on particularly developingtrend——adjustable-pitch blinds .This thesis introduced some typical application examples for references in cold area and discussed the theoretical gist and steps followed by blinds-design, the following problems are solved in this article:1.Theoretic calculation of the blinds'effect on direct solar radiation and diffuse radiation and reflected radiation2. Oproposes certain methods of using the sun lights coefficient,skylight coefficient and relecting coefficient to calculate the illuminance of workplane3.Test the insulation effect of closed blinds when the material and the thickness of air space changed. Heat resistances of wooden louver and aluminum alloy louver are separately 0.33 m2k/w and 0.22 m2k/w. The selected air space has no evident influence on heat resistances .The temperature of test points with wooden louver is less than it with bare window by 43.1%, the temperature of test points with aluminum alloy louver is less than it with bare window by 34.2%.