The focus on low carbon design is now critical for all public sector buildings in line with government decarbonisation targets. Rob Erwood, Sales & Specification Director at Baxi, looks at how one School Trust is approaching refurbishing its buildings for net zero.
Faced with ambitious carbon neutral targets and inflated energy prices, and backed by a desire to lead by example, sustainability has become an increasingly hot topic for schools across the country.
Reducing the carbon-intensity of heat in their buildings is a natural starting point to achieve these goals, with heat pumps one of the favoured solutions. And with funding from the Government’s Public Sector Decarbonisation Scheme (PSDS) making the transition more affordable and achievable, astute school trusts are seizing the opportunity to make the switch to renewable energy.
The Priory Federation of Academies Trust is a case in point, having recently carried out an impressive programme to decarbonise the swimming pool buildings at three of its Lincoln academies. The anticipated savings are considerable with the design of the entire scheme expected to save over 200 tonnes of CO2 a year, equivalent to planting 7,000 trees.
High energy demand
Swimming pools have high energy demand, as the pool water needs to be heated continually to maintain comfortable temperatures, while shower facilities in the changing rooms add to the energy requirement. At Lincoln Academy, Witham Academy and LSST Academy, gas boilers were previously heating the water in the pool and Air Handling Units.
Renewable energy installer Oakes Energy Services collaborated with heating and hot water solutions provider Baxi to assist the Trust with its ambitious sustainability initiative, replacing the gas boilers with air source heat pumps (ASHPs).
At Witham and LSST Academies, two Remeha 88kW ASHPs now supply all the heat demand in each of the swimming pool buildings, feeding underfloor heating and radiators, and providing hot water for the changing rooms and the swimming pool plant.
At Lincoln Academy, which has a larger 25-metre swimming pool, five Remeha 88kW ASHPs supply heat to calorifiers for the hot water system as well as to the swimming pool heat exchanger in the first phase of the decarbonisation programme.
The proposal for each academy was designed bespoke to the individual requirements in each building, but all involved retrofitting Remeha energy-efficient ASHPs and Megaflo hot water cylinders.
Early planning
Heat pumps have a huge role to play in helping schools on their journey to net zero. But a whole range of factors — from the variety of building type to available funding and time constraints — will influence how quickly and easily refurbishment can be achieved. And with no one-size-fits-all solution available, a project-by-project approach is critical.
So how did the Trust go about setting in motion this ambitious decarbonisation programme? Early planning was key. Working with Oakes Energy Services, design proposals were developed, illustrating an estimated annual saving of 227.5 tonnes of carbon. These were then used to secure PSDS funding. With funding in place and the competitive tender process won, Oakes produced detailed building heat loss calculations — essential for accurate sizing of the heat pump units — and completed an assessment of the electrical infrastructure to ensure sufficient capacity to site.
The location of the ASHPs also needed to be determined, with their footprint, maintenance clearances, noise levels, hydraulics and electrical connections, general aesthetics and any necessary planning permissions all factors for consideration. A full assessment of the heat emitters and pipework was then carried out to check suitability and determine any upgrade requirements. Once this information was in place, a full programme of works could be drawn up to minimise disruption to the building.
Close collaboration
From product availability to technical support and final commissioning, working closely with manufacturers will help contractors ensure that projects run smoothly and to schedule, as Nik Smith, Director at Oakes Energy Services, explains: “As with all school projects, we were working to a tight, fixed deadline. However, having the Remeha heat pumps in stock was a big selling point as this gave us more time to complete the project ahead of the start of the new term.
“In addition to onsite technical support during the installation stage, Baxi also provided pre-commissioning support and commissioning to meet the handover date. All in all, a great service from the Baxi team.”
Draw on industry experience
As this project illustrates, while the merits of heat pumps are well established, the
technology alone is not a decarbonisation panacea. Partnering with experienced renewable energy installers and manufacturers and involving them at the early stages provides the opportunity to draw on their knowledge for optimal results.
With early engagement, the heating industry will be able to collaborate fully to help schools reap the many benefits of heat pumps with minimal disruption, using detailed forward planning and a project-by-project approach to design. Putting plans in place now will help make what may initially seem a major undertaking become a valuable and achievable route to greater sustainability.
Tips to prepare for heat pump integration
- Monitor energy usage and data — this will make it possible for designers to understand how and where heat pumps can best be used.
- Space — is there sufficient external space for the heat pump?
- Electrical connections — is there sufficient capacity? It’s likely that additional power requirements will need to be brought to site, so understand the achievable options.
- Avoid delays — ask your consultant to notify the local Distribution Network Operator (DNO) at the outset and complete the necessary connection application form.
More information on Remeha’s ASHPs here: www.remeha.co.uk/Products/Heat-Pumps
Header image: Two Remeha 88kW ASHPs were installed at Witham Academy
