RADIATORS


www.heatingandventilating.net Net Zero reality


Isaac Occhipinti, Director of External Aff airs, MARC


We already know that moving UK homes over to low carbon heating systems like heat pumps and hydrogen boilers is the likely route, but what does that mean for the existing heating system


Ancillary considerations


Houses built as new from the early 1970/80s (believed to be present in an estimated four- to fi ve-million UK homes) are often fi tted with microbore central heating pipework. Air source heat pumps require a relatively higher primary fl ow rate when compared to gas boilers, this is a problem for microbore pipework, and so system suitability would need checking. It could prove expensive to replace a home’s pipework and alternative solutions may have to be pursued.


Education I


do not need to convince anyone that Net Zero is happening. We have moved on, and now we turn our attention to how. We already know that moving UK homes over to low carbon heating systems like heat pumps and hydrogen boilers is the likely route, but what does that mean for the existing heating system, in particular the heat


Emitters and ancillary pipework?


The demand for central heating in UK homes began in the 1970s. As a result, many domestic systems are now old and ineffi cient. Heating appliances have been replaced - mainly through age or a homeowner’s decision to upgrade. However, the system component parts, such as radiators, cylinders, and controls are typically left unchanged due to cost, inconvenience, or complexity. This is where low temperature heating system installations become more Complex. Low-temperature heating systems, like heat pumps, require diff erent system


design, mainly to ensure that the heat emitters (radiators, fan-assisted radiators or convectors, or underfl oor heating pipes) can deliver the same amount of heat at the lower temperature as a traditional radiator system would have done at normal temperature (over 55°C). Suffi ciently sized heat emitters would be necessary to support this, as lower primary fl ow temperatures require a higher surface area. On the fl ip side, homes that have added insulation measures after the original central heating install may now have eff ectively oversized radiators for the heat loss of the building. Retrofi tting homes with low temperature heating systems will require a


room-by-room heat loss calculation, based on BS EN 442, the Installer can then establish if existing radiators are eff ectively oversized and able to run at lower temperatures, or if radiators need to be exchanged for larger/ multiple panel radiators. Of course, it is advisable to change very old, less-effi cient radiators due to corrosion or incompatibility with Thermostatic Radiator Valves (TRVs).


Extensive retraining of the installer base will be necessary for any successful transition. It is fundamental for the correct selection and delivery of heating systems, and therefore should take highest priority, once the allowable technical solutions, and selection processes are agreed.


This will ensure the correct assessment of existing systems, as well as the identifi cation of appropriate technologies and system improvements, including design, installation and commissioning. All low-carbon technologies require this to ensure the


theoretical energy savings are realised in practice. Consumer awareness campaigns are also needed to help homeowners


understand why transition is vital. This should include information about diff erences in performance and why behavioural changes are necessary to extract the best energy savings and carbon reductions.


To conclude


No matter the heat source of choice there is a radiator to suit. To ensure maximal effi ciency and thermal comfort radiators must be considered when fi tting a new low temperature heating system. Designing for such systems from new is relatively straightforward but considerable work is needed to prepare legacy-building stock for a Net Zero economy. This challenge is made more diffi cult by the UK’s disparate housing stock, dominated by older properties using mains gas as the main heat generation source. Currently, the majority of replacement gas boilers are ‘distress purchases’ due to the failure of the original appliance. Straightforward incentives need to be in place to encourage homeowners to improve levels of insulation and to upgrade their entire heating and hot water system. These incentives must cover the heating system in its entirety, including radiators. To outline where improvements need to be made and how diff erent domestic


systems can be aligned with the country’s long-term goals, MARC has launched a comprehensive whitepaper entitled Heating up to Net Zero.


28 December 2021


DOWNLOAD THE HVR APP NOW


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36