New type of window with slim frames and large daylight and solar energy transmission

The aim of the project is to investigate the possibility of developing a new type of windows with a slim frame construction integrated in the glazing. The total frame area should be decreased by approximately 50% relative to common windows leading to a 20% increase of daylight and solar radiation transmission. Two different solutions will be investigated both using fibre glass reinforced polyester profiles - a sealed glazing unit and a very light ventilated glazing unit, which should get a lifetime comparable with other building constructions (roof, walls). Beside the enlarged transparent area to total window area the distance between the glass panes should be increased in order to minimise the thermal bridge effect of the traditional rim seal solution. The large distance between the glass panes allows for built-in solar shading devices and/or night insulation between the glass panes in the light ventilated solution. The two solutions will be investigated in parallel in close co-operation with the industrial partners and prototypes should be made for measurements of total heat loss coefficient, total solar transmittance and for tests under realistic climatic conditions. Especially the risk of condensation inside the light ventilated solution requires a detailed study and real test.