In 2022, Kilfrost GEO was selected as the heat transfer fluid of choice to support an exciting new heating network in the rural village of Swaffham Prior, where residents and businesses were taking the step to move away from oil fueled boilers.
In response to a UK priority of making low carbon, renewable heating available to households, residents of a Cambridgeshire village set about on a project to reduce reliance on oil heating and address fuel poverty and environmental issues.
Swaffham Prior, like many rural UK villages, is not connected to the mains gas network. Therefore, before the project began most of the 300 village homes, two churches, a pub and school were heated using carbon-intensive oil heating – with the remainder of the properties using liquefied petroleum gas (LPG) or direct electric.
Working with the local council and a provider of energy, digital and industrial transformation the residents began looking at ways to supply ultra-low carbon, affordable heating for every resident, businesses and school.
A hybrid heat pump system with a solar farm was identified as the best solution.
Through the use of thermal testing, it was identified that the most efficient heat source would come from coupling Ground Source Heat Pumps (GSHPs) with Air Source Heat Pumps (ASHPs). This would mean fewer ground loops would be needed and ASHPs are a beneficial source of heating during the summer. This would allow time for the GSHPs to replenish, ensuring the heat pumps in the ground work more efficiently.
Committed to ensuring energy efficiency at each point, even the back-up gas boiler was switched to an electrode boiler, powered by solar panels. This back-up form of heating will be there to give a boost on the coldest days or when the GSHPs and ASHPs require maintenance.
As conventional heat pump technology is unable to achieve 72°C efficiently, the comparative temperature identified as that provided by oil-fired heating, initially a heat transfer fluid with ammonia was selected as it can generate higher temperatures. However, use of this fluid would introduce risks around toxicity and flammability.
To address these risks, whilst still delivering a good Coefficient of Performance (CoP), Kilfrost GEO was selected. It is bio-derived, non-toxic and classified as non-hazardous in accordance with CLP/REACH. It has also been tested to and exceeds ASTM D1384-05 corrosion test standard at 88°C.
Prior to the pipework being filled with GEO, Kilfrost supplied its SF10 Cleanser for the removal of debris, welding slag and potential chemicals and residues left over from the manufacturing process. A concentrated pH neutral fluid, it is an effective cleanser of the pipework system, in adherence to building regulations and the BSRIA BG29/2020 pre-commissioning cleaning of pipework systems guide.
Following this process, Kilfrost’s SF20 Sanitiser was used as a stabilised, fast acting, oxidising disinfectant before the system was then topped up with Kilfrost GEO. For this project, Kilfrost delivered 137,000 litres of pre-mixed and ready for use fluid, at a -10°C freeze point.
Kilfrost GEO was selected for this project owing to it being biodegradable and non-toxic. Other features of GEO that make it most suitable for the systems were its lower viscosity and higher heat capacity, compared to competitor brands. Which results in slower flow rates and smaller pressure drops being incurred, easing the hydraulic strains on a closed loop system.
How residents in Swaffham Prior are benefiting from its new heat network.
Buildings signed up to the scheme have had a heat interface unit installed, which receives heat from the energy centre. Operating at temperatures of 70 – 75°C, the heating system is compatible with existing central heating systems – meaning residents didn’t have to make additional changes to infrastructure.
Kilfrost was delighted to have been involved in this pioneering retrofit of a village’s heating system. In 2023, the project won the Edie Net Zero Award for Renewable Energy Project of the Year recognising the impact of the green and sustainable project that has transformed the energy landscape of the village for the better.
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