Reduced capital expenditure of more than £7,000 per dwelling
Resident savings of an estimated £120 per year on bills
Reduced return temperatures from 55°C to 32°C
"Since the scheme opened, the heating system has been fabulous. Residents regularly tell me that they've never had such low heating bills. It's a wonderful system for ensuring the wellbeing of our residents."
Housing and Care Manager, Housing Association
Background
The client is a well-established housing association in the UK that sees heat networks as an important way of delivering affordable, low carbon energy to thousands of customers. The project is a 60-unit dementia friendly scheme for those over 55 years of age in Devon.
Challenge
The housing association set an ambitious target to transform the way that it provided heat and wanted to use the project development – an extra care development of 60 new apartments for over 55-year-olds – to set new standards for the heat network industry. The main focus for this project was:
- Capital cost
- Heat cost to residents
- Quality Assurance of design
- Reduction of maintenance
FairHeat Solution
FairHeat supported the housing association through the design, commissioning, and ongoing operation of the scheme.
Design out overheating risk and high resident bills
- Review of pipe sizing
- Increase insulation
- Direct radiators with pre-settable flow limiting TRVs
Changes made to design following FairHeat’s advice included reducing pipe sizes based on dynamic pressure modelling in place of industry standard pressure losses, changing from indirect to direct heating and from 70°C to 60°C, and improved insulation specification.
Ensuring that the system performance matched the design intent. Sometimes referred to the performance gap
- Acceptance testing
- Working closely with the contractor
FairHeat used its innovative Acceptance Testing process to ensure that the scheme’s network was performing at optimum capacity before the client accepted it from the contractor. Issues picked up and corrected included optimised equipment settings and radiator balancing.
FairHeat also used the Guru Pinpoint system extensively to feedback the performance to the contractor to enable them to reattend and correct commissioning issues.
Ensure the excellent performance seen at handover is maintained
- Ongoing performance reviews via Guru Pinpoint
- Water testing
FairHeat continued to use the Guru Pinpoint system to review the performance of the network and provide feedback to the client. In addition, continuous water testing was implemented to ensure the quality of water was maintained.
Results
The hybrid solution within Phase One was able to demonstrate the following benefits to the development:
The design review process reduced capital expenditure of more than £7,000 per dwelling through smaller plant, pipe sizes and the change from indirect to direct HIUs. In addition to capital cost savings, with the improved efficiency of the heat network, the residents save an estimated £120 per year on bills with customer bills typically lower than £5 per week.
Changes made during FairHeat’s Acceptance Testing process saw return temperatures from 55°C to 32°C.
Since handover in 2018, the network has consistently operated with flow temperatures of 60C, even during the winter months. In addition to low flow temperatures, the average return temperature throughout the last year has been 32C. On occasion this temperature drops to below 30C. Network heat loss per dwelling of 71 W/dwelling during the summer have been recorded while the scheme was fully occupied, which is significantly below the recommended value of 100 W/dwelling recommended in CP1 2020.
The low temperature design means that the scheme is future-proofed. The scheme can be easily converted to run on other low temperature renewable technologies such as heat pumps.
Converting to a heat pump will require no other modifications to the system.
