Windows with an improved energy balance of 30%

The aim of the project is to improve the energy performance of windows for residential buildings with at least 30% relative to common standard. The energy performance is regarded as the net energy contribution from the window, i.e. the difference between usable transmitted solar radiation and the heat loss during the heating season.
The thermally weak parts of the windows are the spacer forming the rim seal in sealed glazing units and the window frames. Especially with respect to the frames, this part of the window often forms an area of 30% of the total window area - an area that has a higher heat loss coefficient than at the centre of the glazing and futhermore is opaque, i.e. the heat loss will not be compensated by transmission of solar radiation. The project investigates the possibilities of making smaller and better insulating window frames and to eliminate or decrease the thermal bridge effect of the rim seal spacer. A promising result will be made as a prototype for testing in the laboratory.