The radiator industry has responded to the challenge posed by lower temperature heating systems using renewable methods, as Chris Harvey from Stelrad Radiators explains
The development of lower temperature heating systems, utilising renewable heating appliances – such as ground source and air source heat pumps – has given the heating industry another challenge, but it’s one it has risen to.
However, the key points to remember are that radiators are compatible with all heating systems – traditional and renewable – when sized correctly. Whatever type of technology you choose to share heat, you need to consider upping the quality and scope of the insulation in the property to ensure the heat doesn’t escape.
Despite what you might read in some magazines and on websites, radiators are very much able to provide the levels of comfort heating and hot water required in UK homes, when paired with heat pumps. But the arrival of the low temperature heating system has brought with it perhaps understandable questions that architects, building designers, specifiers and installers want answers to; can we still use products we use now with traditional boiler driven heating systems if the heat source is a heat pump? And, is there anything we need to consider that we currently take for granted?
The answer is, of course, yes – but we do need to look closely at how to ensure that the heat generated is shared effectively in the new home or property, or the existing home or building that is having its heating system upgraded.
In addition to developing aesthetically pleasing radiators that – far from simply being heating appliances – have become design features in a building, radiator manufacturers have developed products that meet specific requirements. These include offering additional robustness in certain applications, or additional rust resistance in areas of high humidity, as well as low surface temperature (LST).
Renewable heating systems
But it’s in the area of renewable heating systems – low temperature heating generated by environmentally friendly heating options like heat pumps – that arguably, the radiator industry has achieved most. It has developed and enlarged the capacity of K3 radiators – three panels and three fins on a radiator footprint that is scarcely larger than a traditional K2 design – but which offers an additional 50% metal surface area over a K2 to share more heat from a similar area. It has added larger radiators to most of its ranges to allow the radiators everyone has grown used to, to be relevant to lower temperature systems and to operate comfortably with air source heat pumps in particular, which are having a major role to play as the heating system horizon changes to accept these renewable options over the next few years.
The radiator industry has developed a wider range of designs and sizes; this has helped to provide the larger radiators needed by the renewable heating options, but also vertical radiators for wall areas with a much reduced horizontal footprint.
Upgraded Building Regulations
The arrival of the new upgrade to Building Regulations with effect from June 2022 in England (and from November in Wales) brings with it a realisation that the key figure to bear in mind is 55°C – the new maximum flow temperature for all new wet heating systems. The regulations also say that heating appliances and radiators should not be oversized. TRVs need to be fitted to every radiator except where there is a room thermostat fitted. The differential between the flow and return should be 10°C – giving a 45°C return, and a mean water temperature of 50°C. This will have an impact on radiators but simply means that sizing of radiators is more important than ever, and all the advice you could need is available through relevant websites to point installers and specifiers in the right direction with regard to using the right radiators in the right applications.
So do we need to ditch radiators altogether and look for alternatives as some are suggesting? The answer is a resounding ‘no.’
Radiators are very much ‘fit for the future,’ but as always, correct sizing will need to be undertaken to ensure that they work effectively. But can radiators work well with air source heat pumps? Absolutely – and the evidence is there, in a host of installations across the UK.
Chris Harvey is head of marketing at Stelrad Radiators