Wolfgang Streicher

Institute of Thermal Engineering, Graz University of Technology
Inffeldgasse 25/B, A-8010 Graz
Tel: +43-316-873-7306, Fax: +43-316-873-7305,

E-Mail: streicher@iwt. tugraz. at, heimrath@iwt. tugraz. at

Additional authors

Thomas Mach, Richard Heimrath, Karin Schweyer, Robert Kouba,
Institute of Thermal Engineering, Graz University of Technology, Austria
Alexander Thur, Dagmar Jahnig, Irene Bergmann,
Arbeitsgemeinschaft ERNEUERBARE ENERGIE, AEE INTEC, Austria
Jurgen Suschek-Berger, Harald Rohracher,

Interuniversitares Forschungszentrum fur Technik, Arbeit und Kultur, IFZ, Austria,
Helmut Krapmeier, Energieinstitut Vorarlberg, Austria

Introduction

The energy demand of new buildings has been decreased significantly during the last 25 years. This is due to the development of new building materials and building technology. Whereas 10 years ago common windows had a U-value of 3 W/(m2K) today’s U-values are half of this at the same price. Similar developments have been achieved for other building materials which results in a specific energy demand of only one sixth (50 kWh/mPa) of today’s buildings compared to buildings 30 years ago without additional costs. With little higher investment cost the energy demand can be decreased even further.

Low energy buildings (or passivehouses) have different demands for the heating systems than conventional buildings. This paper deals with these demands and an analysis of various heating systems with respect to end-use and primary energy demand, greenhouse relevant emissions, heat delivery costs (including capital costs) and qualitative criteria.

The passivehouse is defined by

Max. 15 kWh/mFa space heat demand (with ventilation system with air heat recovery)

Max. 42 kWh/mPa total end use energy demand including electricity for HVAC and others Max. 120 kWh/mPa total primary energy demand

The main goal was the development of a comprehensive evaluation method for heating systems for buildings insulated according to passivehouse criteria.

This project was financed in the frame of the Austrian Research Initiative „Building of the Future" of the Federal Austrian Ministry of Transportation, Innovation and Technology (BMVIT).