Intelligent textiles help cut heating costs - Researchers work on adaptive thermal protection for buildings
BÖNNIGHEIM, (im/ri) With the development of intelligent textile materials which are not only translucent but also able to adapt their thermal permeability to suit the ambient temperature, researchers at the Hohenstein Institute in Bönnigheim and the ITCF in Denkendorf are now paving the way for innovative canopies and sun screening roller blinds. These will be able to act automatically/intelligently to allow infrared radiation to pass through or be reflected depending on the need for heating or cooling and so will make a significant contribution to cutting the cost of heating or air conditioning.
With the products available until now, a compromise always had to be made between letting in heat and letting in light, depending on the current situation. The drawback with conventional sunscreening materials is that, as well as keeping out the heat (the infrared radiation), they also keep out, or screen, the visible light spectrum.
Modern architecture in particular, where the buildings have a high proportion of glass in the interests of allowing for natural and energy-saving light, has proved problematic in summer - because in addition to the visible light that is wanted to brighten the rooms, glass allows the heat to pass through too. Until now this has meant that buildings, especially offices with lots of computers, became extremely overheated, requiring more energy for air conditioning as a result.
Specially coated glass, which keeps out the heat radiation in the sunlight, can help here, but it continues to keep the heat out in winter too. This stops the rooms from being heated by direct sunshine at a time of year when it would be desirable and would help reduce heating costs.
This dilemma can be solved with the new textile sunscreening materials. Since these have both heat-reflecting and translucent (light-permeable) properties, they are able to adapt intelligently to the time of year (environmental temperature). This will mean that in future, when external temperatures are low, the incoming IR radiation can be used as heat energy, while, when temperatures rise, the IR reflection will prevent excessive overheating and so cut the running costs of air conditioning systems.