Simplified metrics for advanced window systems. Effects on the estimation of energy use for space heating and cooling

Abstract

Simplified metrics (U-value, g-value) are often used to energy use for space heating and cooling when conventional windows are adopted, but they are not fully capable of describing the thermophysical behaviour of more advanced windows. In this paper the impact of these metrics on the estimation of the energy use for space heating and cooling in case of a double skin façade is evaluate. The results of the investigation for one climate show that, even if the inaccuracy for a double skin façade is higher than for a conventional window, the inaccuracy is still acceptable in the preliminary design phase.