Short-Term Measurements for the Determination of Envelope Retrofit Performance

Short-term monitoring for estimating thermal parameters of a building, along with an analytical technique to (1) determine the long-term performance and (2) calculate the parameters from a building description, has many valuable applications, which include energy ratings, diagnostics, and retrofit analysis. In this paper we address issues relating to reducing uncertainties in estimating thermalparameters with emphasis on retrofit applications. In general, it is necessary to impose a known heat flow with a suitable profile to reliably estimate the parameters. This is demonstrated with test cell measurements taken before and after changes were made to the test cell. The eventual goal of this project is to develop a practical methodology to determine long-term retrofit performance fromshort-term tests.