Heat Smart, Live Green: How Radiators Power Sustainable Design By Jackie Kilgallon, Specification CentreManager at Zehnder Group UK


interior design. Whether driven by a passion for eco-friendly living or a need to comply with regulations, designers must prioritise sustainability in their projects. Bathrooms and kitchens, as high-usage areas, particularly benefit from efficient heating solutions. But how can radiators enhance sustainabilitywithout compromising performance?


S


Understanding Radiator Efficiency in Design First, let’s clarify a common misconception about radiator efficiency: all radiators are 100% efficient in converting energy into heat. Actually, it is their effectiveness (rather than efficiency) in extracting heat from the heating system and delivering it into the space that varies. Some radiators provide higher heat output per unit size, but this should not be confused with greater energy efficiency. For example, cast iron radiators are often


thought to retain heat better. While they do cool down more slowly, they also take longer to heat up, meaning total energy consumption is similar in the end to lighter alternatives. What really impacts sustainability is not heat retention alone but the overall performance of the radiator in different heating scenarios.


Optimising Radiators for Low-Temperature Heating Systems Modern regulations, like Part L, emphasise the importance of low-temperature heating systems,


32 BKU MARCH 2025


ustainability has evolved from a trend into a necessity in modern


such as air source heat pumps. Many assume that radiators are incompatible with such systems, yet most modern designs perform exceptionally well at lower temperatures. In fact, they often provide better responsiveness and comfort compared to alternatives like underfloor heating. The thermal conductivity of the materials used


to manufacture the radiator and the volume of water in the radiator can affect the thermal response time – for example an aluminium radiator will heat and cool faster than a cast iron radiator – which can be good in terms of reaction times to changes in space usage (e.g. when the occupancy in a room changes) but some thermal inertia is required to maintain consistent comfort levels. Certainly, the amount of radiant heat given from a radiator (in comparison to the amount of convected heat) will influence both the reaction times of the heating system and room as well as potentially achieving comparable comfort levels with air temperatures 1-2 degrees lower.


Sustainable Manufacturing and Material Choices But sustainability isn’t just about efficiency - it begins with how a radiator ismade. Forward-thinking manufacturers, such as Zehnder, reduce carbon footprints from the outset by utilising renewable energy sources. Innovations like laser welding in production minimise energy consumption and waste, making the entire lifecycle of a radiator more sustainable. Additionally, materials like steel, aluminium and


iron are highly recyclable, ensuring that radiators have a minimal environmental impact at the end of


their lifespan. Investing in durable, high-quality radiators also reduces replacement frequency, further contributing to good sustainability practices. For designers looking to assess a radiator’s sustainability, frameworks such as CIBSE TM65, Environmental Product Declarations (EPDs) and Life Cycle Assessments (LCAs) offer valuable insights. While comparing different products can be complex due to varying calculation methods, reputablemanufacturers will provide transparency in their environmental credentials, making choices easier to navigate.


Why It Matters Integrating sustainable heating solutions in bathrooms and kitchens is about more than just compliance - it enhances both aesthetics and functionality. High-quality, sustainable radiators are often better designed, longer-lasting and more energy-efficient, delivering long-term value. From a financial standpoint, energy-efficient radiators lower running costs, making them attractive to homeowners. By choosing eco- conscious solutions, designers not only contribute to a greener planet but also enable them to create healthier, more efficient and more comfortable living spaces.


www.zehnder-radiators.co.uk


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  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52