Part L, Aluminium Radiators and Heat Pumps: A Winning Combination

With the revisions to Part L of the Building Regulations still fresh in people’s minds, and the figure of reducing carbon emissions in new homes by 31% grabbing the headlines, it’s fair to say that the industry is continually looking for new and improved ways to comply. It’s probably also realistic that these revisions will be tightened again in due course in order to meet the 75–80% reduction in carbon required by the Future Homes Standard in 2025.

This certainly makes sense on paper. But when you talk to homeowners who are either building new properties or renovating existing ones, there’s a lot of confusion about what’s achievable and what will work for their homes. Some people think that using a heat pump automatically means they have to install underfloor heating if they’re renovating. It’s scaring some owners away from including renewables in their homes, even though the benefits are several-fold – from both a financial and environmental perspective.

The revisions to Part L outline the move towards new heating systems being designed with lower flow temperatures – at a maximum of 55°C. As you would expect, with the push towards decarbonisation, and the forthcoming boiler ban, discussion about heat pumps continues to set the agenda.

And that’s why aluminium radiators come to the fore.

Everyone is familiar with the traditional steel panel radiator that has been ubiquitous in UK houses since they were invented in 1855. However, over the last few years, there’s been strong growth in the use of high-performance aluminium radiators. There are a few reasons for this.

Aluminium radiators have very low water volumes and much higher heat conducting capabilities – especially in comparison to their steel panel cousins. The science behind this difference lies in the chemical composition of the two materials, with aluminium’s lower thermal inertia ensuring it takes much less time for a radiator to meet the desired temperature.

And, because aluminium radiators heat up and cool down more quickly, there is less chance of ‘overshooting’ the desired temperature – resulting in significant energy saving. This makes them the perfect choice to use with the lower flow temperatures demanded by the revisions to Part L and the more general take up of heat pumps.

Aluminium radiators have other benefits too. For example, they’re around 50% lighter than their steel counterparts – making installation much easier – while also providing flexibility in structural consideration for large projects, such as apartment buildings.

This flexibility is mirrored with different styles and sizes. Our much-loved Decoral 97 range, for example, comes in both horizontal and vertical configurations and has outputs (at Δ50°C) ranging from 277 Watts to 4kW. Along with a 10-year warranty and options for different colours, the range is proving a popular choice to combine with renewable systems, such as heat pumps.

It’s not just heating systems that make the difference when it comes to decarbonising our industry. There’s also something called embodied carbon, which the UK Green Building Council defines as: “the total greenhouse gas emissions (often simplified to “carbon”) generated to produce a built asset. This includes emissions caused by extraction, manufacture/processing, transportation and assembly of every product and element in an asset.”

This is where aluminium radiators demonstrate significant advantages. If we take our Decoral radiators as an example again, they are manufactured from 100% recycled aluminium. The aluminium recycling process requires only 5% of the energy used in the production of the primary metal, equating to a carbon footprint of 0.5kg CO₂e per kg of aluminium produced, compared to 6.7kg CO₂e/kg from primary extraction. And further carbon reductions are made, thanks to the manufacturing plant being located less than nine miles from the raw material supplier. This allows the radiators to be constructed using recycled aluminium that’s still in liquid form.

These combined advantages provide significant sustainability benefits over other aluminium radiators including a 90% reduction in emissions and 80m³ saving in natural gas usage. Plus, aluminium is endlessly recyclable – without ever losing its properties, which guarantees a low carbon footprint.

As the UK moves away from traditional ways of heating homes and embeds renewable technology into its building fabric, we’ll all need to think about our approach differently. Homeowners will inevitably learn to embrace lower flow temperatures and seek ways to save energy and reduce carbon emissions, which guarantees aluminium radiators will continue have a strong part to play in a sustainable future.

Originally published in PHAM News