Within less than a generation, natural gas has gone from being the ideal domestic fuel 鈥� clean, efficient, affordable 鈥� to being a sinful, planet-killing curse.
Gas-fired heating is being rapidly phased out. By 2026, no gas boilers will be permitted in new-build homes in the UK and by 2035 no new gas boilers will be permitted in any home, new or existing.
Now the focus is on low-carbon alternatives, most of which burn electricity generated by wind or solar energy rather than carbon-belching oil and gas.
One of the most comprehensive UK research projects ever carried out into electrical heating systems has recently completed and published its results.
Researchers at the Energy House 2.0 research facility at the University of Salford, working with house-builders Bellway and Barratt Redrow and construction materials manufacturer Saint-Gobain, have spent the past 12 months testing 14 different heating systems to see which ones will heat consumers鈥� homes most effectively and at the lowest cost.
This article was first published in the January 2025 issue of 色猫直播 Magazine. Sign up online.
Energy House 2.0 is a specially-built climate chamber that recreates temperatures ranging from -20藲C to +40藲C, as well as simulating wind, rain, snow and solar radiation. The chamber enables Barratt Redrow, Saint-Gobain and Bellway to test methods of construction and products at temperatures and weather conditions simulating anything from a Nordic winter to an African summer.
Inside the test chamber are two typical three-bedroom houses: Bellway鈥檚 The Future Home and Barratt Redrow鈥檚 eHome2, each fitted with an array of heating systems and incorporating various advanced construction materials.
Richard Fitton, professor of building performance at the university, says: 鈥淲ithout the unique facilities we have here at Salford it would take years to deliver these results that we have achieved in just a few months of testing on each home.
鈥淓nergy House 2.0 allows for a comparison between heating technologies at constant extreme temperatures, which up to this moment had not been possible and our results represent unique research. These insights will be invaluable as we try to reduce the carbon emitted in heating our homes, whilst ensuring people are warm and comfortable in their homes without paying too much on their bills.鈥�
The systems tested at Energy House 2.0 covered a range of technologies including infrared heat panels, floor-mounted and roof-mounted air source heat pumps (ASHPs), underfloor heating, skirting board heating and traditional radiators.
This article was first published in the January 2025 issue of 色猫直播 Magazine. Sign up online.
All methods of heating the homes were measured in the same chamber conditions reflecting typical (5掳C) and more extreme (-5掳C) winter temperatures found in the UK. This allowed a comparison to be made between these technologies that up to this moment had not been possible.
One of the most significant findings of the research is that the pattern of usage has a significant influence on the efficiency of the heating system employed.
The researchers compared two different approaches to heating a home:聽 24-hour constant heating and a twice-daily regime whereby the house is heated between the hours of 07:00-09:00 in the morning and 16:00-23:00 at night. This pattern is currently used in the standard assessment procedure (SAP) and is typical of the way that most people heat their homes in the UK.
The most common method of heating a home in the UK is still a traditional gas boiler and wall-mounted radiators. Gas boilers are designed to reach output temperatures of up to 70oC quickly and be used for short periods to fit around the typical consumer鈥檚 lifestyle 鈥� delivering bursts of heat in the morning and evening as reflected in the current SAP assessment model.
Air source heat pumps do not reach such high output temperatures and are seldom capable of producing more than 50oC. They work best by raising the temperature in the room and maintaining it over time, rather than heating the space rapidly for quick heat.
Although they can work well with traditional radiators, the Salford research found that they proved especially effective when used with underfloor heating 鈥� except when used in the conventional twice-daily routine.聽 Underfloor heating does not perform well when used in this way because a significant amount of energy has to be dumped into the floor structure before it starts to heat the room itself.
In its summary of the main findings of the research, the Salford team concluded that the infrared systems demonstrated the lowest system efficiency of all the systems tested, although they would heat the rooms quickly and give good levels of thermal comfort.
鈥淭hey also struggled to reach the required heating requirements at low [test] chamber temperatures which simulated extreme winter conditions. This was felt to be due to under-sizing rather than an issue with the technology,鈥� says the report.
The performance of the air source heat pumps fell in line with expectations and performed well, although 鈥渘ot as well as could have been expected if they were perfectly commissioned and set up鈥�, said the researchers. The one ASHP that did not perform well was the roof-mounted system, a prototype unit provided by Worcester Bosch.
鈥淭his did not perform as well as the other heat pumps, which could have been explained by its unique nature and early-stage development,鈥� concluded the researchers.
One of the most significant areas of underperformance was found to be in the heat emitters, namely the radiators and infrared panels. 鈥淭his could have been due to the fact that the emitters were under-designed or the commissioning was not effective,鈥� says the report. Underperformance here led to a significant degree of underheating, particularly at the lower chamber temperature simulating extreme winter conditions.
The aim of all this research is to find ways of insulating our homes and finding the most efficient heating systems, both for environmental reasons and to reduce fuel costs. But some people might be surprised to learn that, despite heat pumps proving very efficient and much less environmentally damaging than gas, a house heated with ASHPs will usually get a lower Energy Performance Certificate (EPC) rating than the same home heated with gas.
This article was first published in the January 2025 issue of 色猫直播 Magazine. Sign up online.
鈥淟ow carbon homes aren鈥檛 necessarily low-cost homes,鈥� says Jamie Bursnell, head of technical and innovation at Bellway.聽 鈥淓PCs [energy performance certificates] are more about running costs than carbon reduction.鈥� Electricity is, unit for unit, still significantly more expensive than gas.
鈥淵ou can get an A-band EPC by employing a combination of solar PV and a gas boiler thanks to the low cost of gas, the efficiency of the boiler and the free electricity from the rooftop PV,鈥� explains Bursnell.
鈥淚f you replace this combination with an air source heat pump you can reduce your carbon emissions by 75-80% which is in line with the Future Homes Standard that comes into force in 2025. But when you do this, your EPC comes down to a B-band because electricity is more expensive.
鈥淒espite that, we have proven that an air source heat pump can heat a home for 拢1.85 per day. That鈥檚 important because it assures the customer that switching to a heat pump doesn鈥檛 have to cost them more,鈥� he adds.
Bellway鈥檚 home demonstrated that underfloor heating and air source heat pumps work well together, while infrared heating could be used more widely in flats and maisonettes, where ASHPs are difficult to install.
The research indicates that as the technology used to heat our homes evolves, so too must the way we use that technology. Flicking the boiler on for a quick burst of heat will become as anachronistic as throwing an extra log on the fire.
And while it may be some time before low-carbon systems like ASHPs are the default choice for home heating, that time is certainly approaching. Bellway is already conducting pilot projects around the country, with 11 exemplar homes already completed. Last year the company installed 163 ASHPs in homes across the country and it has plans for a further 1,400.
People in warm glass houses
Salford University鈥檚 Energy House 2.0 facility provides an invaluable test-bed for manufacturers and designers seeking new energy-saving solutions.
While Bellway, Barratt Redrow and Saint-Gobain explore electric heating systems and building fabric innovations, another firm 鈥� CI Group 鈥� has ventured out of the main structure and into the conservatory to study the performance of a new type of insulation product.
CI Group specialises in conservatory insulation, an area of particular interest to Salford University鈥檚 Professor Richard Fitton: 鈥淲e have several million conservatories across the country, and the idea that they鈥檙e not that efficient yet still people heat them is a concern.鈥�
CI Group鈥檚 new product is called CHRIS 鈥� which stands for Conservatory Heat Reflective Insulation System 鈥� and is designed for installation under an existing conservatory roof, be it glass, polycarbonate or solid tiles.
The Salford team measured the ceiling U-value with and without the CHRIS insulation.
鈥淲e found that the CHRIS system reduced the heat transfer by around 80%,鈥� says Prof. Fitton. 鈥淎nd how that works when you tie into the rest of the building is the entire heat loss of the building reduced by about 30%.
鈥淭hese figures could make quite a big difference to the way people use, heat and cool conservatories.鈥�
This article was first published in the January 2025 issue of 色猫直播 Magazine. Sign up online.
Grant Henshaw, a research fellow on the Energy House 2.0 project, explains: 鈥淎 key challenge with the future housing stock in the UK is retrofitting because we have the oldest housing stock in Europe.
鈥淪ome 80% of the homes that will be here in 2050 already exist, and a key issue is retrofitting solutions like this one that CI Group has come up with.鈥�
CI Group claims that its new CHRIS product is 鈥渓oosely-based鈥� on the insulation designed by NASA for use on the International Space Station 鈥� though it is clearly not quite as robust.
It uses a six-layer quilt comprising an aluminium foil on both outer surfaces over two layers of thermo-wadding membrane to create air pockets within the structure.
Between the thermo-wadding membranes is another layer of aluminium foil and a vapour-control barrier to prevent condensation.
The CHRIS system is the only insulation product specially developed for retrofitting to conservatory roofs, says the company; competitors cannot replicate its performance without removing the entire roof.
The company developed the design from scratch over 18 months rather than adapt existing products. And although it has been installing the product for the past five years, it only registered the design in 2023.
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