Estimating the thermal transport properties of building components

• Published in: Building and environment 1995-07, Vol.30 (3), p.359-365
• Main Authors: Irving, A.D., Dudek, S.J.M., Warren, G., Dewson, T.
• Format: Article
• Language: English
• ISSN: 0360-1323; 1873-684X
• DOI: 10.1016/0360-1323(94)00058-Z

Real buildings and their components experience dynamic thermal transmission. It is possible to represent thermal transmission as either a superposition of local constitutive convolution equations in a local region of the solid or as a directed graph network between connected thermodynamic regions within the solid. Both the local constitutive convolution and directed graph network representations are based on response factors which can, in principle, be used to estimate the dynamic thermal transmission of the building components. The response factors can also be used to predict the performance of the materials under a range of design loadings. These response factors for each representation can be estimated directly from time series data of the physical observables under general stochastic boundary conditions. Indeed, it can be demonstrated that each of the representations can accurately characterise the thermal performance of building components. The purpose of this paper is to show that only the local constitutive equations yield, for all cases considered, the correct values for the physical properties of the materials under test, whereas the directed graph network representation does not provide consistent estimates. The local constitutive equations allow the measurement of thermal conductivity and transmission of building components in situ, thus providing a unique insight into the actual thermal performance of constructions in use.