Vitocal GSHP breaks new ground in Warwickshire with integrated Solar PV and Energy Storage
Viessmann Domestic GSHP breaks new ground in Warwickshire with integrated Solar PV and Energy Storage
Overview
Mark Rigby’s passion for environmental sustainability is evident in every aspect of his newly self-built detached home in Warwickshire. With beautiful countryside views and near-Passivhaus levels of efficiency and comfort, the high-spec property is also highly self-sufficient thanks to a Viessmann Vitocal 200-G ground source heat pump (GSHP) combined with solar power and energy storage.
Best of the best
When Mark Rigby and his family set out to build their perfect home in Warwickshire, on the one-hectare plot where their old house previously stood, they were clear from the outset that they wanted a GSHP from Viessmann. Mark’s father had installed a Viessmann boiler 25 years previously and was still very happy with it, so they knew it was a brand they could trust. And, with plenty of outside space and access to a family member’s digger for excavating the necessary boreholes themselves they were well placed to take advantage of the exceptional efficiency and extra-low running costs a top-quality ground source system could offer.
Meeting all the young family’s heating, cooling and hot water requirements, the new heat pump forms a central part of a highly effective and virtually self-sufficient energy ecosystem for their high-tech, climate-friendly new home. The set-up also incorporates solar PV panels, battery storage and a mechanical ventilation system with heat recovery (MVHR). At the same time, structural insulated panels (SIPs) in the fabric of the building ensure exceptional thermal comfort and efficiency. The two-storey, four-bedroom, six-bathroom property, which also boasts underfloor heating (UFH) throughout, would have achieved Passivhaus status if not for the inclusion of large windows to maximise the splendour of its natural surroundings.
Scoping the options
Mark started the GSHP installation process by submitting an enquiry via Viessmann’s UK website in April 2024. In response, he was promptly put in touch with Viessmann partner and heat pump expert Daryl Evans of Evans Energy Heating Solutions in Bridgnorth. Daryl was excited to get involved in what would be his first domestic Viessmann GSHP installation. “It’s pretty unusual for a client to want ground source heating in their home, especially now that modern ASHPs have developed to be as good as they are,” he explains. “Most people either don’t have enough outside space or are put off by the drilling costs.”
Daryl and Mark did discuss the comparative benefits and costs of an ASHP as an alternative option, but the homeowner’s mind to install a GSHP system was made up. Nevertheless, it was important to have the conversation. “I wanted to be honest with Mark because there’s no doubt, ground source does cost more to install,” Daryl recalls. “However, when I saw his passion for GSHP technology, I was more than happy to oblige.”
System design
The next step was to carry out a heat loss survey, after which Daryl prepared a quote for the equipment and installation. He specified a Vitocal 200-G 8kW GSHP with weather compensation and a Vitocell 300 litre cylinder to store hot water for the UFH, both from Viessmann. Exceptionally quiet in operation, the Vitocal has a small footprint, fitting snugly inside the Rigby’s garage. It also offers an excellent price/performance ratio for extremely efficient heating, cooling and ventilation.
A further water cylinder from OSO was incorporated in the scheme design, for domestic hot water. The heat pump was sized to provide enough warmth to heat both cylinders, so there would always be ample heat and hot water, even at peak demand times. However, an immersion heater was included, too, for back-up in exceptionally cold weather, as well as an MVHR as mechanical heat recovery was required, due to the house being built to Passivhaus standards. Solar PV panels plus two Tesla batteries for energy storage help to power the whole set-up, reducing the family’s reliance on the grid.
Scheduling
The timeline for the project needed to be flexible to accommodate a number of factors such as ongoing building work at the property, supply schedules for copper wiring and other materials, the electrician’s availability, Mark’s working schedule, and the application process for a £7,500 Boiler Upgrade Scheme grant. The latter is a longer and more complicated procedure in the case of new builds compared to retrofits, with extra evidence required to demonstrate eligibility. And once the funding is agreed, the associated works must be completed within six months, so it’s important to submit the application at the appropriate time.
Fitted in four days
The installation was ultimately scheduled for completion by mid-December 2024. In preparation, Mark spent three weeks in November digging four boreholes into which the ground collectors could be inserted in 200 metre loops.
Daryl had allocated a full working week for the fitting itself, but when the courier was late delivering the new equipment on site, this had to be condensed to four days. That included a day spent purging the ground loops to ensure all the air was expelled before lagging and connecting the blow-up pipes. Nevertheless, the system was up and running perfectly by late afternoon on the Friday.
The following week, John Grist, Commercial Area Business Manager at Viessmann, visited the property to inspect the installation. Says Daryl, “Although I’ve fitted GSHPs before, because this was my first domestic Viessmann installation, I wanted to ensure I was leaving no stone unturned. And this is a top-end product, so John also wanted to confirm it was being fitted to their high standards.” In the event, John was fully satisfied with the set up and made no adjustments.
Results
The Rigby’s are delighted with their new heat pump. Their house stays at a constant, ideal temperature year-round and their energy bills are negligible. In fact, throughout the summer, they did not purchase any electricity from the grid at all.
Mark comments, “I have to say that there is a massive difference with this house compared to our old. The old was draughty, cold, and noisy. Because we made the right decisions, buying and installing good equipment it has meant our house runs very efficiently and affordably.
“I’m no eco warrior by any stretch. But I understand the importance of being as self-sufficient as possible, especially in the current climate of rising fuel bills. The Viessmann boiler we have is already very affordable to run, but paired with our solar and battery set up we are able to decrease these costs further and more be more self-reliable.
“I highly recommend the Viessmann systems as they have lived up to and exceeded our expectations. I’d also like to thank Daryl for his excellent work. He made the process very easy, and he has been a wealth of knowledge.”
“This is a great example of a top-quality ground source installation that will keep performing for many years to come,” sums up Daryl.
Specifications
· Viessmann Vitocal 200-G 8kW ground source heat pump
· 4 x 200 metre loops
· Weather compensation
· OSO Geocoil 300 litre cylinder for hot water
· Vitocell 300 litre cylinder as a heating buffer
· Solar PV
· 2 x TESLA batteries
· MVHR system
· Immersion heater
