Annual experimental research on convective heat transfer coefficient of exterior surface of building external wall

The convective heat transfer coefficient (CHTC) of the exterior surface of a building envelope is a basic parameter that is used to represent the intensity of the convective heat transfer between the envelope and air when planning an energy-efficient building design. To study the convective heat transfer on an exterior surface in detail, as well as the impact of CHTC values on thermal performance calculation of building envelopes, we conducted an annual four-season experimental test on the exterior surface of an external wall via a new method. Dynamic changes in the radiative heat flow, convective heat flow, and total received heat flow on the exterior surface under different seasons were determined. We also obtained the amount of convective heat transfer and radiative heat transfer on a building surface in relation to the total received heat flow, as well as the CHTC and radiative heat transfer coefficient (RHTC) values. Finally, in view of the test results, the maximum frequencies during different seasons were acquired based on the CHTC and RHTC distribution frequency statistics in Xi'an. The value obtained with the new method was validated by analyzing the influence of the exterior surface CHTC on the heat transfer coefficient (RTC). (C) 2017 Published by Elsevier B.V.