Fifteen years ago, when Graham Hendra first began selling heat pumps, they weren’t quite hot
The ex-wholesaler makes the comment, “To get 50C – that was quite hard,” in reference to the water flow temperature that these devices provided to radiators.
Most new gas combi boilers are designed for flow temperatures between 50 and 60 degrees Celsius.
Heat pumps could not have been able to adequately heat certain older homes without additional measures, such larger radiators, taken by the owners. The greater surface area of these radiators makes them more efficient heat transmitters.
Nevertheless, a new kind of heat pump is making its debut. Thanks to innovations in technology, heat pumps can now provide temperatures far beyond 70 degrees Celsius, when in the past they could only deliver lower temperatures.
The emergence of new refrigerants like R290, or propane, represents a significant change.
A heat pump circulates this fluid. A gadget that draws heat from the air around it, known as an air source device, may work even on very cold days. To transmit heat from a building into another space, heat pumps compress slightly warmed refrigerant, increasing its temperature.
If R290 were to leak, it would have less of an effect on climate change than earlier refrigerants since it is less toxic to the environment. This innovation makes heat pumps up to 34% more efficient, allowing them to produce higher temperatures with less waste.
Mr. Hendra has been hired as the technical director of Genous, a firm that provides clients with advice on how to make their houses more energy efficient.
As he put it, “we have a thing in our industry that I call ‘temperature anxiety’,” comparing it to the “range anxiety” that many people who purchase electric vehicles have.
He contends, however, that these concerns are dwindling in significance as a result of the proliferation of hotter heat pumps.
Others, meanwhile, may need further time to change their minds. Under the leadership of Paul Ciniglio, head of whole home conversion at the charity National Energy Foundation, over 500 properties in Bicester are now being renovated.
“We’re trying to get as many as a quarter of them to sign up to heat pumps but it’s proving really hard going,” he says. “There has been so much negative press.”
According to him, “With the advent of this new refrigerant, it could be a game-changer.” He goes on to explain that there are some residents who are concerned that the heat pumps won’t provide enough heat.
Among the renewable energy providers offering R290-based heat pumps is Octopus Energy
The most recent addition to its heat pump lineup, the Cosy 6, has the capability to increase water temperatures up to 80 degrees Celsius. In theory, homeowners shouldn’t have too much trouble switching heating systems, says flexibility head Alex Schoch. “Combination boiler out, heat pump in,” he announces. Heat pumps could be able to access more types of houses in the UK because of the country’s notoriously poor insulation standards in comparison to the rest of Europe.
The aroTHERM plus heat pump from Vaillant can stay operational in temperatures as low as -20 degrees Celsius and provide hot water up to 75 degrees Celsius, even though the manufacturer suggests maintaining the water temperature below 55 degrees Celsius to retain efficiency.
Vattenfall is another company that makes heat pumps that use R744, otherwise known as carbon dioxide. It has the potential to provide much higher temperatures—up to 85 degrees Celsius. The majority of the 300 units that the company plans to install this winter will be for housing organizations throughout Europe.
An official from Daikin claims that the Altherma heat pump, when charged with R32, can reach temperatures of 70 degrees Celsius. Several R290-based heat pumps will be released by the business in 2024.
The Energy Systems Catapult is a nonprofit that has been testing heat pumps in a variety of English and Scottish houses since 2020. They have 742 different kinds of heat pumps. The R290 heat pumps used in the experiment have been successful, says specialist Daniel Logue.
“When averaged over the course of a year, the R290 high-temperature heat pumps were performing significantly better than the R410A heat pumps, which is a refrigerant that’s being phased out now,” he said.
The heat pumps in question consistently kept their COP at 3. Here we have the potential amount of heat energy that can be produced for every kilowatt-hour (kWh) of electrical power that is used. To be cost-effective in comparison to gas boilers, heat pumps need a COP of 3 or above, based on current energy prices.
Even though R290 enables greater efficiency while providing higher temperatures, the greatest COPs are still attained when central heating is run as low as feasible, according to Leah Robson, co-director of Your Energy Your Way, an organization that installs heat pumps, solar panels, and other renewable energy technologies.
She goes on to clarify that heat pumps based on R290 aren’t suitable for all locations. To prevent the flammable refrigerant from escaping, they must not be located near any air bricks or windows at ground level.
Cheshire resident Sue Beesley just had an R290 heat pump installed. Changing her radiators and limiting the flow temperatures to 45C was something she did, even if it wasn’t strictly necessary.
In the end, it will make her system more efficient. “What I’ve got now is a house with a very even temperature all the way through,” she said. The COP for her central heating system is consistently around 4, she says.
Heat pumps’ performance is not a big barrier to their widespread usage in the United Kingdom, according to Professor Mari Martiskainen of the University of Sussex Business School’s Energy Demand Research Centre. “We have supply chain issues, we have skills issues.”
There were only around 72,000 heat pump installations in the UK last year, even though that was the government’s target.
Mr. Hendra claims that additional heat pump options and improved technology would encourage individuals to abandon fossil fuel boilers. In his opinion, the moment has come.
His comment, “We are appalling at heat pumps in the UK,” is an allusion to the recent ranking of the United Kingdom as the twenty-first worst European country, “which is truly embarrassing.”
