Location: Southfields, Wandsworth
Asset owner: St Barnabas Church
Projected energy savings: 10+ tonnes CO2e per annum
Projected financial savings: £6,000+ per annum
Proposed tech:
The church has a high gas consumption at 100,000 kWh per annum. The previous vicar estimated that 70% of the consumption was to heat the main church space. When we carried out the feasibility study on the church, their heating was being switched on first thing on Saturday morning in order to heat the space up to a suitable temperature for Sunday service.
Hydromx heat transfer solution is projected to slash heating demand by 25-35%. Hydromx works by taking more energy from the heat exchanger, making boilers and heat pumps more efficient.
With more energy per litre of fluid, radiators get to temperature faster and heat is held longer in the fabric of the building. The radiator system was flushed clean and then a combination of water, glycol and the nanofluid were pumped into the system in early 2026.
‘We are really pleased with the impact Hydromx has had. Our radiators are heating up faster and are noticeably hotter. This is a relatively simple intervention that had good instant results for efficiency and reducing our carbon footprint. It was good to work with CREW Energy on this project and we are grateful for their support to enable this to happen.’
- Revd Vanessa Elston
During the feasibility stage of this project, it was established that air source heat pumps would be a good fit for the 2009 build hall extension, since the building is well insulated and has high standard double glazed windows. The heat pump was successfully installed in August 2026. Additional Hydromx will also be installed here.
Planning has been approved to install solar panels, with discussions ongoing around capacity.
Battery storage would eventually allow the Church to shift its generation to evening usage when the church is busier. The batteries would also reduce the running cost of the heat pumps in the hall.
Stay tuned for updates on these additional technologies – the easiest way to get updates it by subscribing to our newsletter.
St Barnabas aims to be a place of welcome for people of every age and background, where a thoughtful and rooted faith can be found. In the liberal catholic tradition of the Church of England, we offer a place of worship that is traditional and contemporary, a place where you can think, reflect and pray, and share the journey of faith with others.
They host regular events open to the local community, such as the Wandle Walk and Picnic, and their hall is available to hire.
In March 2021 the church became a Bronze Award level Eco Church, working towards fulfilling the criteria for the Silver Award and helping to make the Diocese of Southwark an Eco Diocese. You can find out more about their Eco Church status on their website.
