REHAU’s RAUTHERMEX pre insulated pipes have been chosen for a major district heating project in Glasgow, where four tower blocks are being upgraded to provide efficient and affordable heating to more than 300 social housing properties.
SSE won the contract to design and install the district heating system in the tower blocks, replacing exsiting stoarge heaters, which were expensive and inflexible to the needs of the tenants. To reduce the pipe size and minimise heat loss, they designed a radial system with a central energy centre powered by 12 new commercial gas boilers. The heat from the boilers will be delivered to plant rooms in each tower block, and from there, the heat can be transferred to interfaces installed in individual flats.
The original performance specification, written by consultants HKA, suggested an exemplar using steel piping throughout the installation, but after consideration SSE proposed polymer piping for a more cost-effective solution without compromising on performance or ease of installation.
Craig Dalrymple, project manager for SSE, said: “The radial design required more than 500m of pipework to run heat from the new energy centre to the four individual tower block plant rooms. To save time on the install and to minimise heat losses over the longer distance, polymer pipes were definitely the better option on paper, so we went with RAUTHERMEX for the installation.”
REHAU’s RAUTHERMEX pre insulated pipes are specially designed for applications where low heat losses are critical, making it ideal for large district heating systems over long distances. Available in single (UNO) or double (DUO) pipe variations in diameter sizes of up to 160mm, the pipes are surrounded by an outer layer of PU foam which is both highly insulating and prevents water from getting in.
RAUTHERMEX comes in coils of up to 570m, allowing for faster and more cost-effective installation. The Glasgow district heating installation required 75mm DUO pipework to be fitted and joined with FUSAPEX fusion joints. The fusion weld joints are chemical and corrosion resistant, extending the life of the installation.
Craig continued: “We had used REHAU products previously on underfloor heating installations, but had not worked with the RAUTHERMEX piping before. Thankfully it was really quick and easy to install on site as it is lightweight and flexible and because of the longer pipe lengths available, we needed fewer joints.”
Jim Macdonald, consultant engineer at HKA, said: “When we were asked by the Housing Association to consult on the district heating installation for the four tower blocks, we originally suggested steel pipework but our performance specification didn’t preclude the use of polymer pipework and we are happy with the change.
“Our primary concerns were to uphold the performance of the district heating system and ensure it would have a lifespan of at least 30 years.”
Steve Richmond from REHAU said: “This particular district heating project is a great example of how polymer pipework is a proven alternative to steel pipework. As well as matching steel for performance, PE-Xa pipes are easier to install as they are lighter and more flexible, and they are much more cost-effective which is particularly important for Housing Associations, where funding for improvements is limited.”
The district heating system in the Glasgow development is due for completion in January 2018.