Heat Pumps Today

16 With the very real prospect that due to Government legislation, air source heat pumps are going to take off in a big way in the UK – initially in new build developments from 2025 but it seems very likely, soon after, in replacement heating systems as well. The means of sharing the heat they generate around our homes has also become a serious consideration. Radiators and heat pumps... are they good partners? Air source heat pump manufacturer LG has been taking a closer look at the potential outcomes looking more closely at existing installations of its series of air to water heat pumps and how they are succeeding in sharing heat within these installations. The development of lower temperature heating systems, utilising renewable heating appliances – such as air source heat pumps - has given rise to a number of questions including where do heating system components we have got to know and love over the years fit into the future of heating? August | September 2021 O P I N I O N More than 90% of all heating systems in the UK rely on radiators to share the heat around the home and despite the arrival of underfloor heating, there is still a marked reluctance to use UFH upstairs in new build and it is a complex option to fit as a retrofit solution – so radiators tend to win out most of the time. Remember radiators are poorly named! Most radiators are actually convectors – there is a small amount of radiant heat from the radiator but more than 80% of the heat is convected heat – drawn up behind the radiator where the air passes over the metal surfaces of the radiator and heats the air in the room. The solution In new build housing, it’s a relatively simple solution. The key to radiators operating well in any situation is to size them properly at the outset, which involves working out heat loss calculations to achieve the necessary number of BTUs required to provide comfort heating in each room and select a radiator that provides that level of heating. In a new build home, the heating system can be designed into the home at the outset so you know the parameters in which the heating system has to operate – the method of construction, the size of the rooms, the number, type and size of doors and windows – so the heat loss calculations can be done up front and radiators sized accordingly. In replacement heating systems for older properties there are additional issues. It’s a fact that simply replacing a boiler with a heat pump will see the existing radiators unable to provide the levels of heat needed in a home. So, what is the solution – one that is cost effective and straightforward? Do we need to ditch radiators and look for alternatives? Increase the size The simple answer is no. Radiators will work well with heat pumps, but you will need to increase the size of the radiators to provide a larger metal surface area to heat the air within the room to the level required to provide comfort heating. This need not involve unsightly radiators – for one, modern radiators are aesthetically far more attractive anyway, but there could be other solutions too. You can achieve the extra boost radiators need by replacing the existing single or double panel radiators Compact with Style K3