Das Projekt "Energy saving in a technology-centre by a passive and active solar system with 'Legis Elements'" wird vom Umweltbundesamt gefördert und von Norbert Kaiser Consulting and Controlling, Ingenieurbüro für Bauwesen durchgeführt. Objective: The project aims to demonstrate the energy saving potential of a 'new developed' transparent insulation material integrated in a large building. In a climatic zone (as Germany) where the application of active and/or passive solar systems is relatively difficult. Even in this climate, the used of the transparent insulation material will reduce the energy needs to nearly zero. General Information: The system is applied to a three stores high office building of a floor area 1700 m2 (per floor). The system, commercialized under the name of 'LEGIS' consists of a transparent insulation applied on the external side of a conventional but not well insulated wall. The wall is painted black, the transparent insulation in front and roller blinds in between. The solar radiation reaches the black wall and transfers its heat into the wall. The roller blinds with reflective characteristics serve to control the solar input and to prevent overheating problems. The system can be applied to the east, south and west side although it should be stated that the at the south side the heat input is to large and should be cut off partly. Therefore part of the south black wall is foreseen of a black absorber connected to the floor radiant heating of the office rooms at the north side. The heat transfer fluiding is water. The system operates as follows: Summer time: The roller blinds are closed during daytime and up during nighttimes (to increase the long wave radiation cooling). The summer conditions are applied if the outdoor ambient temperature is above 15 degree of Celsius. The regulation parameters are: - solar radiation above 20 W/m2: roller blinds down; - average daytime outdoor temperature above 15 degree of Celsius: roller blinds down; - absorber temperature above 60 degree of Celsius: roller blinds down. Winter time In winter time, the operation strategy is inverted. The winter conditions are defined by an outdoor ambient temperature of below 15 degree of Celsius. The regulation parameters are: - solar radiation above 20 W/m2: roller blinds up; - average daytime outdoor temperature above 15 degree of Celsius: roller blinds up; - absorber temperature above 60 degree of Celsius: roller blinds up. Also the windows dispose of roller blinds in between the glazings and can be operated. In winter time, they are up during daytime to enhance the solar radiation input, at night they are down to reduce the heat losses (heat loss coefficient from 3 to 1 W/m2 K). In summer time, they are down during daytime, to reduce the cooling load of the building while diffuse light can still enter the room. At night...