Netherfield, Probus

Ground source review: Netherfield, Probus

Netherfield is an exclusive development of just six individual detached family homes set within private gated grounds on the edge of the village of Probus, near Truro. The luxurious three-floor houses are built near the picturesque Roseland Peninsula looking out over a stream, fields and trees.

Designed to a high-end specification by Jack Burr at Kwalita Design Solutions, a local Cornish architect with a focus on sustainability, each property benefits from the lowest carbon heating technology available; ground source heat pumps, installed by another Cornish company – Roseland Plumbing & Heat Pumps.

The Kensa Evo was a perfect fit

Another brand of heat pump was originally specified for the development’s renewable heating systems, but after Jim met with Kensa in December 2021, the plan changed.

Jim of Roseland Plumbing & Heat Pumps said:

Sourcing the heat pumps for this development froma local manufacturing company instead of one that buys in international units was a no-brainer. I knew that Kensa’s products are all designed for British properties and ‘connect and notify’ approved – this was really helpful, as it meant there were no conformity issues with Western Power. Plus, we had technical help right on the doorstep if we needed it.

The architect and builder were already familiar with Kensa’s Shoebox heat pump and so I introduced them to the Evo model, and we all agreed that with its efficient output and stylish design, it would be perfect for the development.

A mixture of 9kW and 13kW Kensa EvoProduct

Evo ground source heat pumps were installed in each property. The heat pumps are either housed in a dedicated plant room utility area in the basement or tucked away in a garage-type space.

The fact that the ground source heat pumps have the ability to cool without having to install an additional dedicated cooling unit is a real benefit. Lots of glass is being used in the design, and so the cooling functionality is being considered, although it hasn’t been specified yet.

Individual boreholes saved space

Three 80m boreholes were drilled for each property in phases in line with the build schedule, with trenching and manifolds following after. Ground conditions were difficult and the decision was made to drill shallower boreholes but in greater numbers. A Shared Ground Loop Array system architecture was not used on this site, as the properties are being sold as separate privately owned homes with no shared management company.

The site can be tight in places and the borehole drilling rig had to navigate around segways and drainage. Consequently, some of the boreholes had to be drilled at a slight angle to get the correct separation between them.

A highly efficient system design

Working in partnership meant that Roseland Plumbing and Kwalita Design Solutions were able to design a highly efficient ground source heat pump system. The architect was willing to take advice on final floor finishes that would enhance the efficiency of the ground source heat pumps and a concrete finish was used on a number of floors.

The properties have underfloor heating throughout, which is a perfect heating distribution system for the low flow temperature ground source heat pumps.