An In-situ Test Apparatus of Heat Transfer Coefficient for Building Envelope

The measurement of heat transfer coefficient of building envelope is an important project in building energy efficiency test.In order to accurate measure the heat transfer coefficient in situ,the field test experimental apparatus of heat transfer coefficient for building envelope was designed and manufactured by combining the hot-box method and heat-flow meter method.The inside test environment can be artificially controlled by the hot-box to achieve the requirement of temperature difference of each side.The drawback of heat-flow method that the in-situ test must be carry out in heating season was made up by the apparatus,thus the test efficiency and accuracy are also improved greatly.The heat transfer coefficient of a wall for a building was in-situ measured.The experimental results showed that the apparatus has the advantage of shorter testing time and higher accuracy.The in-situ test result is about 55 percent higher than theoretical value.It is reasonable to take field test results and theoretical values as the comprehensive index to evaluate the energy-saving effect to building envelope.