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A not so slippery slope in Kassel

Kassel, Germany
Over 26% reduction of heat loss with Flexalen
A not so slippery slope in Kassel
A not so slippery slope in Kassel
A not so slippery slope in Kassel
A not so slippery slope in Kassel
A not so slippery slope in Kassel

The chance to combine the vibrancy of city life with a high standard of living was just one of the many factors that attracted the Bergweg residential estate. The 15 buildings, each with 105 apartments, are located in Wolfsange, a quiet district on the edge of Kassel with a view of the River Fulda. This area is also just a stone’s throw away from the city centre. Despite the scenic awe of the location, there was one notable downside. The 1970s steel heating and drinking water pipe network was heavily deteriorated, resulting in continuously high heat losses and leakages. The water supply had become unreliable and energy increasingly costly. So Bergweg needed a new, reliable and sustainable distribution network for their domestic hot and potable water supply.

To minimize energy losses during heat transmission, and to ensure long-term reliability, the client and the designers opted for our tried-and-trusted district heating technology - the pre-insulated, flexible Flexalen pipe system. This proved an ideal solution for the unique challenges to be met. Thanks to the system’s comprehensive range of dimensions, pre-insulated, moulded parts and sophisticated accessories, more than a kilometre of single and double Flexalen pipes were laid. The heating system in the first building and the 14 transmission stations were installed in no time.


Firstly, the buildings were staggered up the hillside and had height differences of up to 25 metres. Additionally, the pipes had to be laid in cellar arches that were hard to access without disrupting the use of the existing networks. This demanded a high degree of flexibility. The brief from the consultant designers was clear: to build an energy-efficient, corrosion-free, and maintenance-free district-heating network capable of delivering 715 kW of heating power.


The Fuldablick Property Owners’ Association in Kassel had taken on a formidable project. The underground steel pipe network on their 1970s-built residential estate with its 15 buildings and 105 apartments was in need of an overhaul due to the high heat losses that occurred. Replacing the district heating and drinking water network with a system of flexible PB pipes enabled them to reduce heat losses by more than 26%. With the use of our innovative Flexalen pipe system we could support the Fuldablick Property Owners’ Association in achieving energy savings of around 780,000 kWh per year – that’s equivalent to the average annual power consumption of 80 houses!


Fuldablick Property Owners' Association

ITEGA GmbH (consultant designers)

  • 780000 kWh 
  • energy savings per year
  • over 25 meters
  • of height differences between the
  • 15 buildings
  • including
  • 105 apartments
  • with 
  • 715 kW
  • need for heating power
Michael Biewald
Technical advisor
Sub.: Thermaflex Germany
Fuldablick , Kassel, Germany
0066dda5 7659 4da3 830a 743637e5af6a

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+31 416 567 777
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  Successful in the past - prepared for the future (PBPSA) PDF 1619 KB Preview Download Mail

This brochure is giving an introduction to Polybutene including a review of the performance of Polybutene pressure piping systems in meeting the needs of sustainable building regulations.

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