Because they are so efficient, one of the key drivers behind many district heating schemes is a desire to provide affordable warmth - particularly in the social housing sector and particularly when housing is located off grid.
One recent such scheme was at Dunbeg, Nr Oban, in Argyll, where the West Highland Housing Association opted for a biomass boiler and district heating system specifically to reduce energy costs for residents in a brand new development.
The association built fifty new flats and houses around a community biomass system and used REHAU’s RAUTHERMEX pre-insulated pipework to distribute the heat.
In total, nearly 1100m of RAUTHERMEX was installed - ranging from 25mm Duo to 63mm Duo pipework, connecting via tees to HIUs on the ground and first floor of each property.
The thermal performance of RAUTHERMEX, particularly in the duo pipe version, was key to the specification, with the pre-insulated foam achieving a lambda value of 0.0216W/mK.
Also important was the durability of the pipe on a site where there were unstable ground conditions. TSL, the main contractors, were able to create an on-site borrow pit however, blasting 25,000 tonnes of aggregate on site, which was then processed to use as sub base and general fill material for the pipe laying.
Without biomass, the project in the off grid area of Dunbeg would have been reliant on an electric or oil based heating solution, which would inevitably have led to higher costs for residents.
The project was designed by consultants Campbell Palmer Partnership for the West Highland Housing Association and the main contractors were TSL of Oban. The Housing Association is currently monitoring the energy usage by residents to assess the ongoing performance of the scheme.