he Computer Science Center of the TU Braunschweig was completed at the end of 2001 as an extension to the north side of an existing high-rise building. The building is a reinforced concrete skeleton construction with a staggered storey in a light steel structure. The façade consists of a curtain-type mullion and transom construction made of aluminum with spandrel and lintel panels. The physical properties of the glazing are adapted to the different orientations. The administration building, which is essentially single-skin, encloses an internal, covered atrium through which the offices are accessed. The interior façades facing the fully heated atrium are uninsulated and single-glazed. All six storeys are continuously connected to those of the high-rise building.
In the course of the integral planning process, the open inner courtyard was converted into a glazed atrium at no extra cost and functionally integrated into the energy and ventilation concept as a central component. In winter, the atrium is heated to 18-20 °C by an air heating system with floor outlets in the basement and by flat radiators on the second floor. In summer and during the transitional periods, the atrium is largely freely ventilated. The uplift height of 26 m and the wind suction caused by wind direction-dependent open leeward exhaust air flaps are natural drives. The offices are naturally ventilated via windows facing the atrium and the surrounding area.
With the exception of the cooling systems for the server rooms, there are no other cooling units. Cooling is provided by wall-mounted cold water chests integrated into the individual room controls. The waste heat from the chiller is used to heat the atrium in winter via a heat recovery system.
All lighting and external sun protection functions are coordinated via a LON bus and the DDC control system with the option of decentralized user intervention. The LON-based individual room control system optimizes the heat and power consumption of the lighting and ensures free night-time cooling via the atrium by automatically opening door and window skylights.
The energy concept aims to achieve low energy consumption in accordance with the requirements of the SolarBau MONITOR funding concept (www.solarbau.de). This goal has been achieved and is continuously verified by building monitoring.
This began in February 2002 and records over 200 data points, which are used to make operational adjustments and optimizations. Among other things, the summer temperature behavior of the building and the manual and automatic cross-ventilation are examined. For this purpose, six reference rooms with the same orientation and different equipment are compared with each other.
The integral planning process includes the scientific monitoring of the IT center during the use phase. The aim is to demonstrate the cost-neutral feasibility of implementing the targeted lowest energy standard in office buildings and to ensure room quality and user comfort.
The monitoring will be continued as part of the research project ''EVA evaluation of energy concepts''.