The first construction phase in 1983 saw the installation of the main line from the sawmill to the Abbey Heiligenkreuz. The connections were done using butt-welding by trained welders. The Forestry Commission organized the drainage.
In 1984 the connection of the community buildings (including the town hall, fire department, kindergarten, etc) was realized. One year later, single family houses could be connected to the district heating network too, securing reliable and affordable heat for all connected users.
The objective was to replace the oil boiler in the diocese, and use bark and sawmill biowastes in a biomass installation for the local heat supply. The use of clean, sustainable energy for the heat supply for the Heiligenkreuz village was the focus, but there was also a desire to achieve an improvement in the air quality.
- Installation of main line, 3 m deep and near the stream bed
- High groundwater table
- Highway crossing
- Connection of single-family houses with minimal damage to the gardens
- Overall planning and selection of pumps, home stations, etc.
75 clients including residences, a school, and a kindergarten were connected from the network. Due the flexibility and easy weldability of the material, this could be realized with minimal disturbance to the existing environment and its users. The network’s total length is 3.6 km with heat losses of less than 1°C of the main temperature. The boiler power is 3 Mw + 0.8 Mw biomass, and the nominal power is 2.2 Mw for heating and 2 Mw for wood drying. For the heat supply, up to 10.000 m³ of bark and sawing waste is used. So far, there have been no network maintenance costs, despite the high ground water table. That’s because Flexalen is sustainably resistant to water and mechanical damage, and corrosion-free.
Forstverwaltung Heiligenkreuz (forest management)
Stift Heiligenkreuz (Abbey Heiligenkreuz)