Comparison of the Experimental Measurement Methods for Building Envelope Thermal Transmittance

Building energy consumption and ways to reduce it have drawn increasing attention in recent decades. Thermal transmittance is not only a code-enforced parameter during the design and retrofit phase of building assemblies, but also strongly related to the accuracy of whole-building energy modeling. There are several existing methods to measure the building envelope thermal transmittance, and with the development of new techniques, more practical and precise measurement methods have been explored. The study discussed here focused on comparing methods to measure the building envelope thermal transmittance, both in laboratory and for in-situ measurement. Typical research studies related to the Hot Box Test Method, the Heat Flow Meter Method and the Infrared Thermography Method are described and compared. This paper provides a state-of-the-art review of the up-to-date measurement methods for building envelope thermal transmittance and provides alternatives for engineers, architects and researchers to practically measure the building envelope thermal transmittance.