Low carbon heating and hot water for historic church conversion and newbuild apartments

In Lar Housing Trust’s Fountainbridge development, a space-saving combination of Thermino heat batteries and Kensa Shoebox heat pumps has been installed in 10 newbuild flats and four townhouses in a converted historic church.

The challenge

Lar Housing Trust set out to restore and convert the formerly derelict St Kentigern’s Church in Fountainbridge, Edinburgh, to create affordable rented homes. The 125-year-old church had been closed since 1941 before being converted into four townhouses with modern interiors, with 10 new apartments also built in the former car park.

With no gas supply on site, Lar Housing Trust looked for a renewable heating solution which could work in both the converted and newbuild properties.

Air source heat pumps were considered initially but space constraints meant that these would need to be mounted on the roof. This would be visually obstructive, which was an issue when fitting in with the historic conversion and surrounding Victorian properties, and would make it challenging to maintain the units.

Working with Kensa Contracting, Lar chose networked ground source heat pumps instead, with boreholes drilled underground to access renewable energy and units installed neatly inside each home.

The solution

To create a heat network, six boreholes were drilled vertically under the ground surrounding the church to form two shared ground arrays. Each apartment and townhouse was fitted with a Kensa Shoebox heat pump connected to one of these arrays, and a Sunamp Thermino heat battery to provide hot water.

Thermino heat batteries are up to 4x smaller than the equivalent hot water cylinder and come in a range of litre-equivalent sizes, ideal for Lar’s newbuild flats which range from one to three bedrooms, and the larger townhouses in the church conversion which have three or four bedrooms. Paired with the compact Shoebox heat pumps, this space-saving and efficient heating and hot water solution fits neatly in a cupboard.

Shared ground arrays also have a number of benefits for multiple occupancy dwellings, allowing for efficiencies in system design and installation while still allowing residents to have control over their own heating and hot water, without the need for split billing or metering.

The benefits

The combination of networked ground source heat pumps and compact Thermino heat batteries has already been tried and tested in social housing tower blocks across the UK.

This project shows that the model can also be applied to historic conversions and newbuild developments alike, providing a low-carbon heating and hot water solution while overcoming space constraints within the properties and aligning with Lar’s commitment to sustainable development.

The residents of Lar Housing Trust’s Fountainbridge development will enjoy mains pressure hot water on-demand from their Thermino heat batteries. Combined with the ground source heat pumps, householders can take advantage of flexible tariffs by producing and storing heat when electricity is cheapest, helping them achieve lower bills and carbon emissions.

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