'Achieving net zero in a single bound is a challenge for schools and other end users, particularly for those who have recently installed new gas-fired boilers,' said James Hughes, commercial HVAC vertical market sales manager, Carrier and CIAT UK. 'With many schools, the solution is to help them plan for a phased transition, with upgraded heating infrastructure put in place now, ready for the future switch from gas to heat pumps.'
The phased approach is successfully working at Kepier School in North East England, which installed seven new gas boilers three years ago. CIAT UK worked with project partners BReng Hull, consultant AA Projects, installer Quora Group and equipment supplier Cool Designs, to help develop a long-term decarbonisation plan for the school, with funding under the Condition Improvement Fund (CIF).
'The key is to upgrade heat emitting systems, so the move to low-carbon heat pumps can be made seamlessly when the time comes to replace end-of-life gas-boilers,' said Rob Smelt, managing director, BReng Hull. 'This ensures valuable capital is used to maximum effect, while moving towards net zero on a planned time track with future-ready infrastructure in place.'
A heating audit at the school identified the requirements for a new system of high-efficiency heat emitters. New high-level CIAT fan coil units (FCUs) were mounted within ceilings and on surfaces, allowing the equipment to be installed while the school continued to operate with the existing heating system still using the gas boilers.
The project included removal of conventional radiators and replacement with 31 CIAT Coadis and seven MajorLine FCUs.
'The new units were selected based on the outputs achievable with lower water temperatures,” said Rob Smelt. “This allows the school to undertake decarbonisation in two stages. The new boilers operate at lower temperatures in full condensing mode, saving energy, reducing running costs and cutting carbon emissions. When the boilers are replaced with high efficiency air-source CIAT heat pumps, the correctly sized heat emitters are already in place to enable a seamless transition, delivering immediate savings and spreading investment costs.'
Step one in the decarbonisation process is now delivering significant energy savings for the school. The savings have been enhanced due to the high 80deg C water before the new heat emitters were installed. The new system has reduced the water temperature to 50deg C, yielding a 30deg C reduction in the heating uplift required, and saving 70kw of energy every day during the heating season. This equates to an annual energy saving of 9,800kWhr of gas, and a reduction in carbon emissions of 1,800kg CO2.
The heating audit also revealed some issues with the existing heating system, resulting in wasted energy and poor comfort conditions. Some classrooms were overheating year-round due to inadequate control of fan convectors, with hot water continuing to circulate even though the set temperature had been achieved and the fan switched off. The new system uses dedicated classroom-based controls and inverter-controlled water pumps to further reduce energy use and improve year-round comfort conditions.
'The CIAT units are reliable and highly efficient,' says Rob Smelt. 'In terms of controllability and cost per kilowatt output, no other manufacturer can compete with them.'
Brian Dixon, Estates Manager, Kepier School, said: 'All the work was done out of normal working hours and at weekends, to avoid disrupting the day-to-day running of our busy school. As a result, no lessons were interrupted. This was achieved by careful planning and cooperation throughout the process by all involved.'
Deborah Minns, director of finance and resources, Kepier School, said: 'Learners can now sit for exams in the perfect temperature. We are making savings in energy costs and are fit for the future.'
BReng Hull worked closely with equipment supplier Cool Designs during the scoping and specification stages, supported by CIAT UK application specialists.
Projects such as the phased decarbonisation strategy for Kepier School contribute to Carrier’s 2030 Environmental, Social & Governance (ESG) Goal of reducing its customers’ carbon footprint by more than one gigaton.