Development of new types of low energy windows of composites materials

The background for the project was the tightened energy demands in the Danish Building Regulations, which had and still has the objective to encourage the development of energy efficient building constructions, and at the initiation of the project only a few window products were applicable in low energy buildings class I and II. The aim of the project was therefore to develop specific proposals to frame constructions in glass fibre reinforced polyester that could be combined with both double- and triple-glazing. The project was executed in collaboration with the material producer Fiberline Composites A/S and all the Danish window producers were invited to participate. A few composite window products have been developed during the project, where the producer Pro Tee A/S has launched their product, and another producer is expected to launch it in the middle of 2010. The project treats among other things, apart from the thermal aspect, the hinges and the assembling, and did in total for all reports and articles result in four outward and two inward opening frames. The proposals could be used in all types of windows, but the calculations performed in the detailed simulation programs are based on the standard window size 1230 x 1480 mm. The calculations revealed that it was possible to improve the energy balance, Eref, from -4 to 19 kWh/m2, by replacing a 98 mm wooden frame with a 29 mm composite frame. Likewise was the total annual energy consumption for an office building improved from 30 to 28 kWh/m2 per year and for a single family house from 68 to 57 kWh/m2 per year. The performance of the launched products has been calculated in detailed simulation programs, and the results from these calculations have created basis for a CE-classification, which made it unnecessary to make tests to document the U-values. The project has consequently stimulated the development of the launched composite window products to achieve better energy performances, and is thereby expected to improve the development of window products in the next few years and the future