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Case Studies

A Solar Panel Assisted Heat Pump System in Dorset

Here we walk you through one of our bespoke projects from start to finish, including the briefing, design and implementation of a home’s eco-friendly solar panel assisted heat pump system. This project incorporated the following:

Project Design

In 2015, we were approached by Julia to design and install a new heating system for the renovation project she was undertaking. After our first meeting it was clear that along with a level of ease and convenience, a major requirement was for an environmentally friendly home heating solution.

A hybrid solar heating solution

The building itself was quite large although it would be well insulated. After carrying out room by room heat loss calculations, it was clear that a single heat pump would not be able to cope with demand on its own. Therefore er decided that a hybrid solution would be required – a solar panel assisted heat pump. This system would utilise:

  • a 14kW Mitsubishi air source heat pump
  • a new condensing Viessmann gas boiler.

The air source heat pump would be the primary form of heat. The gas boiler would take over in times of high demand.

Bespoke heat emitting system

For our heat emitters, we kept the existing ground floor rooms on the original radiator circuit, with some of the radiators being upgraded. In new extension on the ground floor, we installed a standard under floor system with a dry screed laid over. The first floor the master bedroom, walk through dressing area and en-suite again were split into 2 zones, constructed with an 18mm cement board overlay system. Our team also installed a new radiator system into the remaining bedrooms. We fitted a separate time and temperature control to the ground floor, as well as for the bathroom towel rails. Including hot water, there are 7 separate zones within the property!

Finding The Right Fit

Julia was very keen on solar (both photovoltaic and thermal) and also rain water harvesting.

A Solar Panel Assisted Heat Pump

Having talked through the available roof spaces and levels of shading, we decided that solar thermal would not be suitable for the overall design. However, due to the hipped shape of the roof construction, a triangular shaped solar PV array would be aesthetically pleasing. Therefore, to create the effect we were looking for, we chose the Trienergia range of panels using a mixture of both square and triangular shapes.

Rain Water Harvesting

We installed a 5,000ltr shallow dig rain water tank into the back garden, rerouting all the rain water from the down pipes through the tank. We also fitted and installed all of the property’s toilets, washing machine outlet and 4 outside watering points into the rain water system. Our plan ensured that a submersible pump within the tank would provide a pressurised supply to each outlet. A manual override is present in case of drought or pump failure.

Additionally, we also installed a Charnwood Cove 2 multi-fuel stove – our team fitted this stove into a custom built fire place complete with log stores, ornament recesses and a TV recess. We fitted a pure drinking water filter to all mains cold water outlets within the property, as well as 3 new bathrooms.

We would like to say a personal thank you to Julia for taskingĀ energy BY DESIGN with the project. It was such a pleasure to be involved with a large scale transformation of a local property.


Our supply, survey and installation service covers the following areas: Bournemouth, Christchurch, Dorchester, Poole, Romsey, Salisbury, Southampton, Wimborne and Winchester and other areas in Dorset in Hampshire. Site surveys outside a 30 mile radius of Wimborne will incure a charge a Ā£25 which is deductable should you accept our quotation. We are also pleased to invite enquiries from further afield.