Cooling energy from absorber diaphragm walls Coordination of the architectural concept and the absorber technology during the planning stage leads to the ideal solution in terms of architectural design and costs. - Completion: 1995 - Floor space: 3,336 m2 - Heating capacity: 100 kW - Cooling capacity.: 100 kW - Client: Province of Vorarlberg - A - Architect: Peter Zumthor, Haldenstein - CH - Building services consultant: Meierhans Partner AG, Fällanden - Zürich - CH Cooling energy: Obtained using 24,000 linear metres of PE piping in 4,500 m3 of concrete required by structural design (diaphragm walls). The energy concept: The wet subsoil ensures the constant availability of cooling capacity which can be tapped using a minimal amount of energy. As a consequence it was not necessary to dissipate heat at night during the summer, normally such an important consideration, and it was then possible to provide the outer surfaces of the building with extremely good insulation. This means that the building is isolated from the external weather conditions and provides for optimum operating conditions during the heating period. Any heat flow which does penetrate the insulation is absorbed by the piping installed between the structural fabric of the building and the outer insulation – for either heating or cooling purposes. Based on the basic floor space, the energy consumption required for heating is calculated as 7-8 W/m² at ta = -15 °C and in the absence of interior thermal loads. Summertime energy consumption is limited to the power required to drive the circulation pump for the piping systems in the subgrade and in the fabric of the building. In the winter the pumping rate for the subgrade cooling loops is reduced to a minimum while a small gas-fired boiler is currently used to cover the remaining heating requirements. (N.B.: A heat pump using an antifreeze/water mixture would serve this purpose equally well). Isolating the room climate from outside weather conditions has the effect of reducing internal loads. It was therefore possible to reduce the volume flow of conditioned air to a total of approx. 2,000 m³/h for the exhibition areas. This gives a total air change rate of less than 0.5 an hour. This air volume proved to be sufficient and the required air duct network was small enough to allow it to be integrated into the architectural concept. Cost saving: Through use of the new enercret technology with its future-oriented energy concept it was possible to reduce the investment costs from EUR 2.5m to EUR 0.9m and the operating costs from EUR 15,000 to EUR 2,600 p.a. as compared to a conventional air-conditioning system. Project sheet download: To download the PDF file, please click here .* ) * ) To view PDF files you will need the Adobe Acrobat Reader. If you do not have this software, you can download the Acrobat Reader here free of charge.