Daikin heat pumps get an inspiring place in Dorset landmark’s renewable future

Athelhampton House has been sympathetically ‘modernised’ to embrace renewable energy – with Daikin Altherma 3H HT air source heat pumps playing a key role alongside ground source heat pumps and photovoltaic panels.

What was the vision?

Current owner Giles Keating says: “Athelhampton House is now over 500 years old. We have a vision for the development and preservation of this building and gardens that will ensure a successful future for the next 500 years. “A very important part of that vision is to make the entire site carbon neutral in operation. We started working on this idea several years ago and had progressed the basic concepts of generation, storage and heat generation to a point where we felt it was feasible with current technology.”

Was there any challenges?

H2ecO’s Mike Stephenson says:  “We face a lot of negativity and incorrect information about renewable heating systems’ ability to heat anything other than modern, well-insulated buildings. This project demonstrates that a building typically considered impossible to switch to renewable heating can be converted – and operates successfully.”

As a first step, where possible, floor and roof insulation was improved to minimise future heat loss. At the same time, the project team investigated alternatives for ‘green’ power and heating.

The R32-based Daikin Altherma 3H HT is a split system available in various capacities from 8-18 class, for single or three-phase power. With a single fan, the outdoor unit is significantly quieter than earlier models of similar capacity. Each is paired with a Daikin Altherma indoor unit which transfers energy to a heating circuit and DHW cylinder. The indoor units are either wall-mounted or integrated with a floor-standing hot water cylinder.

At Athelhampton, the wall-mounted indoor units are housed in-house in two plant rooms. Four of the Daikin units heat two 400-litre quad coil domestic hot water cylinders serving the new accommodation areas that are available for family groups and weddings.

Elsewhere on the Athelhampton estate, a large ground collector array was buried in a three-acre meadow, to serve three 15kW ground source heat pumps that deliver heat and domestic hot water and for the coach house. A fourth ground source heat pump serves the cottage.

Previously, Athelhampton relied on deliveries of gas and oil for heating. Electricity outages were frequent, so the site also had a large diesel-powered generator.

Giles Keating says: “The final plans required a mix of heating technologies and locations to work around the physical constraints of the site. The overall plan was completed on a realistic timescale and deadlines relating to funding and grants were all achieved. Parts of the project were supported by the Non-Domestic RHI and Low Carbon Dorset.

“We now use the installations to help educate groups of interested parties, including teams from the UK’s most famous historic buildings as well as local schoolchildren, on what can be done with renewables and have already converted people to the cause of decarbonising by showing them what is possible with commitment and the correct application of technology to help mitigate the climate change emergency.

“Interpretation panels are installed at the site so all of the visitors can learn about the project. The project is included in the official guide book and staff are trained to talk to visitors about the project.

“The first 12 months’ operational data shows that the target energy reduction and carbon emissions are being achieved.”