Assessment of Thermal Bridging Heat Loss by Means of the Infrared Thermography Technique
Thermal bridges influence the thermal standard of a building envelope. They are taken into account in the linear thermal transmittance or Ψ-value, and can be estimated from tabulated values for standard building details or from numerical modelling. However, these methods are not applicable for existing buildings with unknown structure. In these cases, in situ measurement of the Ψ-value is necessary. In this study, a methodology to measure the actual thermal bridging performance is developed. The methodology is based on a infrared thermography technique, which can be used on any existing thermal bridge. To ensure high accuracy, temperature-dependent surface heat transfer coefficients are calculated using the surface temperatures recorded by the infrared camera. The methodology has been validated under steady state conditions in a hot box apparatus with very good agreement.
KeywordsBuilding envelope Hot box Quantitative thermography technique Thermal bridging
Financial support acknowledgment to Enterprise Ireland, Innovation Voucher IV-2014–4203 and College of Engineering and Informatics, National University of Ireland, Galway, Postgraduate Scholarship.
The authors would like to thank SIP Energy Ltd., Athenry Co. Galway, and particularly John Moylan, for delivery of the test specimens.
- 1.EN ISO 10211 Thermal bridges in building construction—heat flow and surface temperatures—detailed calculations (2007)Google Scholar
- 2.I. Benkő, in Quantitative Analysis of Thermal Bridges of Structures Through Infrared Thermograms. Proceedings of International Conference on Quantitative Infrared Thermography Qirt 2002, Dubrovnik, Croatia (2002), pp. 203–208Google Scholar
- 7.M.J. Moran, H.N. Shapiro, B.R. Munson, D.P. Dewitt, Introduction to Thermal Systems Engineering: Thermodynamics, Fluid Mechanics and Heat Transfer (Wiley, New York, 2003)Google Scholar
- 8.EN ISO 8990 Thermal insulation—determination of steady-state thermal transmission properties—calibrated and guarded hot box (1997)Google Scholar
- 9.EN ISO 12567-1 Thermal performance of windows and doors—determination of thermal transmittance by the hot-box method—Part 1: Complete windows and doors (2010)Google Scholar
- 10.ISO 18434-1 Condition monitoring and diagnostics of machines—thermography Part 1: General procedure (2008)Google Scholar
- 12.EN ISO 6946 Building components and building elements—thermal resistance and thermal transmittance—calculation method (2007)Google Scholar