Roof-mounted air source heat pump to guide route to net zero

The roof-mounted heat pump, said to be the first in the UK, will be tested in the Future Home, Bellway’s experimental eco house at Salford University.

Air source heat pumps are expected to replace natural gas boilers in most homes when they are phased out from 2025. They are already installed in a number of new homes, where they are usually fitted to, or adjacent to, an exterior wall where they dominate a property’s external appearance and take up outdoor space.

The Future Home is being built by Bellway inside a climate-controlled chamber at the university as part of its £16m Energy House 2.0 research project, which is part-funded by the European Regional Development Fund. The home will test low-carbon technologies and their impact on the cost of living.

Bellway has engineered the house to support the 200kg air source heat pump within the roof space. A second unit will be fitted to an external wall to enable comparisons between the two.

In a statement, Jamie Bursnell, group technical and innovations manager for Bellway, said: “Installing an air source heat pump within a loft space is a bold move – one that no UK developer or retrofit project has previously attempted.

“During the research period we will have people living within the home to test the performance of the heat pump during real-life use. If the unit in the loft performs well, it could create a new way for homeowners to reduce their carbon footprint without compromising on space or aesthetics.

“It is well documented that air source heat pumps could increase running costs but so far there is little reliable data on their performance. We are looking to find the optimum settings to maximise effectiveness and minimise cost for our customers. We will be able to compare the data from the two heat pumps to determine the most viable option for the future.”

The Future Home will also test underfloor and infrared heating, plus a range of low-carbon innovations including mechanical ventilation, double versus triple glazing, battery storage for solar energy and a shower which transfers heat from wastewater to warm the incoming mains supply mains.

Bellway worked Worcester Bosch to prepare for the trial and Donaldsons Timber Systems redesigned the home’s timber frame to accommodate a Bosch 3400i Hydrotop Solution unit.

Darran Burrage, UK new build director at Worcester Bosch, said: “One barrier for existing properties to convert to a heat pump is size and location. By placing an air source heat pump in the loft of The Future Home, the trial will hopefully pave the way for an alternative location and if successful enable more homeowners to see the technology as a viable greener heating alternative in the future.”

“The development of Energy House 2.0 has taken over six years and £16m of funding,” added Richard Fitton, Professor in Building Performance at Salford University. “Our work with some of the largest house builders and product manufacturers in the UK will help to answer difficult questions about how we reach zero carbon target in future housing.  The facility will help us to stress test these buildings under extreme hot and cold climates, to provide data on energy efficiency and overheating in homes.”

Bellway’s Future Home at Salford University is in its final stages of build and in the new year guests will be invited to stay in the home so data can be collected on the effectiveness of each innovation.