Improved methods for evaluating base temperature for use in building energy performance lines

Abstract

The use of degree-days in building energy monitoring and targeting has often given rise to misinterpretation of results, which has in turn undermined con” dence in such techniques. Anecdotal reporting has, by turns, suggested the use of degree-days either works very well, or does not work at all. This ambiguous position is not helpful to energy managers who need robust tools and clear guidance on their use. This paper presents evidence to show how energy/degree-day correlations i.e., building performance lines, can be properly identi” ed, while taking account of the correct (and practical) energy balance of the building. In doing so it shows how the correct building base temperature can be identi” ed from reduced data sets, while demonstrating that such a practice is desirable. Performance lines constructed in this way, where appropriate, give rise to greater accuracy and reliability of results, while forming the basis for improved diagnostics.