69 HPM 0413

HPM April 2013

Got a story? Ring us on 01732 748041 or e-mail twood@unity-media.com UNDERFLOORHEATING Finding flexibility fit for the future Richard Edwards, of Robbens Systems, looks at the challenges faced by installers working with underfloor heating and explains why water-based systems are set to take centre stage in a more sustainable future... The money saving, aesthetic and environmental benefits of underfloor heating (UFH) are now widely recognised by installers and end-users alike, making it an increasingly sought after domestic heating solution. However, the question of which type is best – water-based or electric – is one that tends to divide opinion among installers. Both systems have their place when it comes to meeting different projects’ needs, but with installers often more familiar with electric systems, the true extent of the flexibility offered by water-based systems can sometimes be overlooked. Many installers see electric systems as a more convenient option, as they are straightforward and quick to fit, with lower upfront costs. This makes them a particularly popular choice for smaller or single-room projects. However, although they do typically cost less to buy outright, their high outputs (usually around 150-200W per m2) mean they can be significantly more expensive to run than their water-based counterparts. There is also minimal build-up height when working with electric systems. While this means they are well suited to retrofit projects, on the other hand it limits room for vital insulation. As a result, electric systems are often over-specified to compensate for heat loss, which in turn reduces overall efficiency. WWW.HPMMAG.COM Comparatively, water-based systems have much lower outputs (typically 70-100W per square metre). Provided they are paired with sufficient insulation, they lose very little heat and tend to be far more energy efficient as a result. When looking at system temperatures, it is also important to consider floor coverings. For instance, while the high heat output of electric systems mean they work well with less dense floor coverings such as tile, they can cause heat damage to other types of covering (e.g. wooden floors). In contrast, water-based systems operate at much lower temperatures, making them ideal for use with all kinds of floor coverings – even timber. What’s more, the increased availability of pre-assembled manifolds, quality components and pre-configured temperature blending units means installing water-based systems is now quicker and easier than ever. Due to the technological differences between hot water pipes and electric cables, water-based UFH also has a much longer life expectancy than electric. With pipes lasting 50 years plus, they provide long-term durability and peace of mind. In today’s political context, installers specifying UFH are increasingly required to integrate systems with renewables – and the introduction of government measures like the Green Deal and the Renewable Heat Incentive means demand for renewable energy is only set to grow. Installers in 68 APRIL 2013 HEATING & PLUMBING MONTHLY the know about which system works best with sustainable energy sources now have a clear advantage with customers looking to reap the benefits of government incentives. Unlike electric systems, water-based UFH is ideal for integration with renewable heat sources. As they run at much lower flow temperatures of 35-60°C, they are perfect partners for heat sources such as air source and ground source heat pumps. This means that customers are not only able to benefit from a green energy source and financial incentives from the government, but they can also enjoy discreet UFH in their home at the same time. However, in order to achieve maximum efficiency from both systems, it is crucial to ensure the property’s insulation levels are as high as possible. The draughtier the building, the less likely it is that technologies like heat pumps will be able to perform to their full potential. For this reason, modern, airtight buildings are best suited to the job. It is also worth considering that the integration of water-based systems with renewables currently works best in projects with solid floor systems – but with UFH technology constantly evolving, there is definite scope for it to complement other floor constructions in the future. HEAT-LOSS CALCULATION To establish a property’s exact heating requirements, it is essential with water-based systems to carry out a bespoke heat-loss calculation. All reputable UFH suppliers will offer this, and will factor in elements such as the size, shape, location and construction of the building. This not only determines the exact water temperatures required from the heat source for maximum efficiency, but it also helps identify areas of high heat loss (e.g. near large windows or patio doors) – indicating where pipes need to be laid closer together to compensate. While both electric and water-based UFH have their unique capabilities when it comes to meeting customer needs, installers who are used to working exclusively with electric systems could be missing out on a whole host of possibilities presented by water-based UFH. Water-based systems offer unrivalled flexibility and efficiency. What’s more, thanks to their low outputs, they integrate seamlessly with renewable heat sources – meaning that, as green government schemes gain momentum, they are set to become an increasingly important part of the future domestic heating landscape. enquiry number 150 Flexible multilayer composite pipes make water-based underfloor heating quicker and easier to fit than ever


HPM April 2013
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