Following the successful completion of a retrofit project in 225 of New Linx Housing Trust’s stock in 2008, in 2012 Kensa were approached by the social housing provider again to undertake a new build ground source heat pump project in 53 of its properties in Brackenborough Road, Lincolnshire.

The project remit was to install new Kensa Compact High Temperature ground source heat pumps in external enclosures to each property, connected to a district heating scheme using a communal borehole ground array; the largest example of a communal ground array serving individual heat pumps.

Space restrictions and billing issues do not favour plant room scale appliances in new build properties, so the use of a communal borehole ground array connected to individual heat pumps solved this issue and qualified the project for the commercial RHI Phase 1 tariff as it is deemed a district heating scheme. Typically, a separate ground array serves eight to ten properties in order that the installation could proceed in parallel with the different phases of the construction programme.

Although somewhat counter-intuitive, the standard Kensa Compact low-energy Grundfos pump is able to circulate the heat transfer fluid around the communal array should a single property call for heat as the required flow rate to satisfy such a limited demand is extremely modest. From a tenant standpoint, low temperature radiators mean the expected seasonal performance factor is sufficient to generate running cost savings compared to the use of a mains gas boiler.