RAUTHERMEX Plus chosen for district heating scheme

REHAU’s RAUTHERMEX Plus pipework has been chosen for a district heating installation in Glasgow, which aims to provide more than 350 homes with affordable, low carbon heating.

The Hillpark Drive estate in south Glasgow was built in the 1970s and the estate, consisting of eight individual apartment blocks containing 351 flats, is operated by Glasgow Housing Association (part of the Wheatley Group).

In 2016, Glasgow Housing Association announced it had secured a £2.5m grant from the Scottish Government’s Local Energy Challenge Fund and funding from Glasgow City Council to put towards a £5m project to upgrade the heating systems installed in the Hillpark Drive accommodation. The project’s objectives were to help provide affordable heating for its social housing tenants, reduce carbon emissions and make the estate more sustainable.

The Hillpark Drive apartments had electric storage heaters fitted, which were inefficient and expensive to run. Project consultants WSP/Parsons Brinckerhoff suggested these were replaced with a low carbon district heating system, powered by an innovative industrial air source heat pump by Star Refrigeration, never before seen on a project of this scale in the UK.

The heat pump would be supported by energy generated by solar panels (to be installed on one of the apartment blocks) and gas would be used as a back-up energy source if and when required.

Although the estate is very large, the linear layout of the 8 apartment blocks leant itself well to a traditional district heating installation with a single energy centre to generate heat for users. Heat would then be transferred from the energy centre down a central flow and return spine pipe, with individual branches coming off to provide heat to each block.

When considering the choice of materials for the pipework, the consultants looked at both polymer and steel alternatives, and carefully considered how each would perform and how easy they would be to install.

Due to the long pipe runs required, heat loss was a major concern for the consultants as this would impact the efficiency of the system. To minimise heat loss during transport, REHAU’s RAUTHERMEX Plus, for example, boasts a high performance polyurethane foam insulation which has excellent thermal insulation properties to guarantee ultra low heat losses.

In terms of ease of installation, polymer district heating pipework also competes well against steel alternatives. Steel pipework needs to be joined every 12m, whereas polymer pipework is available in lengths of up to 570m. It is also very flexible and pipe runs are easily joined together with compression joints, which offer a leak-free seal without the need for o-rings or tightening up once the system is pressurised.

After speaking to REHAU about its district heating offer, WSP/Parsons Brinckerhoff decided to specify more than 1km of RAUTHERMEX Plus to be used on the Hillpark Drive project. The pipework chosen to be installed was a mixture of UNO and DUO RAUTHERMEX Plus pipes with sizes ranging from 110 mm UNO (one pipe) to 250mm DUO (two pipe) RAUTHERMEX Plus.

This innovative district heating system served predominantly by the air source heat pump will help provide heating and hot water to the residents of Hillpark Drive and Pentland Road at affordable rates which will help tackle fuel poverty in this area.

With a service life of up to 50 years, the RAUTHERMEX Plus piping is capable of providing heat to the Hillpark Drive estate residents for at least two generations.

Steve Richmond, Head of Marketing and Technical in Building Solutions at REHAU, said: “The Hillpark Drive installation is a fine example of how to make social housing more energy efficient and sustainable for the benefit of both the tenants and the environment. The project is the first in a number of ways, and we are very proud to have been chosen to be part of it.”