Research On System For Field Test Of Air Leakage Through Building Exterior Windows

Building envelope is the primary problem in energy-saving. Air tightness of windows is an important factor that influences the energy consumption of air conditioning in buildings. In order to improve the indoor thermal environment and energy conservation, there is an urgent need to improve the air tightness of windows. Therefore, the study on on-test technique of air tightness of building external windows is an urgent need by technology development on current building energy saving.The method and technique of on-site test are studied in this paper, under which an on-site test system based on LabVIEW is designed and developed.Certain relations and differences exist between generating mechanism of air permeability and natural ventilation. In processes of practical calculation, many scientific researchers and project designers use some of the same basic concepts and calculation methods of flow, which confuses the essential differences between them. This paper analyzes the calculation method of air permeability and the on-site testing method.On the experiment table, the experiment table of on-site test is built based on the principle of plenum box. The experimental system includes plenum box, blower, differential pressure transducer and some pipelines. The measurement of the volume of air flow could be made on this bench.On the soft development, the test system has been developed based on LabVIEW, which developed data acquisition program and data processing software in graphical programming language, and help the interface to be clear and operate easily.The apparatus of this experiment based on LabVIEW has been developed and used in practice in Changsha housing block. The repeat results of experiments show that the apparatus is reliable and has good performance. At last, all the experiment data has been made the uncertainty analysis.The above experiment results indicate that the research is helpful to perfect the apparatus for measuring the air tightness of windows and develop the energy saving in buildings.