A simple model for assessing the energy performance of windows

A simple model for the annual energy balance of the window taking solar rad iation and heat losses into consideration has been further developed and an alysed. Hourly meteorological data for the solar irradiation and the outsid e temperature are used together with the optical and thermal performance of the window to evaluate the net energy heat flow through a window. The mode l renders a very simple way to compare different advanced windows in differ ent geographical locations. orientations and buildings using basically only the balance temperature as building input. The energy balance and the cost efficiency for several glazing combinations are evaluated for buildings wi th different balance temperatures in a typical mid-Swedish climate. This mo del has a potential to be used for energy rating of windows. (C) 2001 Elsev ier Science B.V. All rights reserved.