068 HPM 0415

HPM April 2015

Got a story? Ring us on 01732 748041 or e-mail twood@unity-media.com UNDERFLOORHEATING UFH: Demystifying the retrofit myth Neil Young, indoor climate applications manager at Uponor UK, outlines what’s been holding the industry back and how it can move forward... Domestic underfloor heating (UFH) has undergone a significant reputation shift over the last decade – shedding its tag of a luxury product only available to the wealthy, to becoming the heat emitter of choice among the new build housing market. However, UFH has always faced one major stumbling block within the domestic heating market - retrofitting into existing properties. Over recent years, the energy saving benefits of a water-based UFH system, as well as the improved ‘comfort factor’ (compared to convection heating), have not gone unnoticed. The steady rise in demand in the UK has encouraged greater product development and consequently wider accessibility to the product. However, for existing homeowners there remains a perception that water-based UFH technology is not viable for retrofit projects. UNDERSTANDING THE OPTIONS While retrofitting water-based UFH has traditionally presented a number of problems, thanks to more recent innovations it has become possible. Historically, installers were faced with two options - digging up the existing floor and laying a traditional UFH system as if it were a new-build, or installing an overlay system on top of the existing floor. Both have their merits, yet they also come with their own distinct disadvantages. Completely removing an existing floor in a property in order to install a UFH system is a costly and time consuming process for both the installer and the homeowner. Firstly, the entire area must be cleared and the existing floor dug out before a new UFH system can be installed. Installing UFH this way ensures adequate flooring insulation can be fitted prior to the system install - maximising the overall efficiency of the new system by minimising heat-loss through the floor. This method negates any potential loss of floor height for homeowners as well. However, the overall cost and inconvenience to the homeowner is often considered too high and as a result it is realistically only available to a limited few, who have the cash to invest in such a WWW.HPMMAG.COM The energy saving benefits of a water-based underfloor heating system, as well as the improved ‘comfort factor’, has seen underfloor heating rise significantly in popularity in recent times procedure. It is not a mass-market retrofit solution as, despite the reduction of energy bills associated with UFH, due to its low operating temperature, the cost of completely gutting a property is unlikely to be recovered by the savings on future energy bills. As such, while this method is effective, it is not economical. The other traditional retrofit UFH option available is the overlay system. It can be installed over the top of an existing screed floor and, once a position and route for the manifold has been identified and subsequently fitted, the installation can be completed in a short amount of time. The process involves either laying pipe on-top of a mat and then stapling it down, or using floor panels with pre-determined pipe grooves. Once laid and tested, the pipe can 68 APRIL 2015 HEATING & PLUMBING MONTHLY be covered with a further layer of screed. When dry, the desired floor covering can then be fitted. Compared to the previously discussed method, using an overlay system will result in a much quicker and cheaper installation. However, in most cases an overlay system will take at least an inch off a room’s height. It is important to stress this to a homeowner as it will inevitably mean that other retrospective actions must be taken, such as planing doors, skirting boards and other permanent fixings. On paper, this may not sound like much, but it is surprising how different a room can look with such an increase in floor height, and some homeowners may not be too pleased with this change if they were not made fully aware of the visual difference beforehand. NEW TECHNOLOGIES While the two aforementioned methods of installation do offer homeowners effective access to water-based UFH systems in existing properties, they are not without their compromises. However, the rise in consumer demand for UFH has led to the emergence of more innovative system designs, including streamlined overlay systems such as Uponor’s Minitec system, which can add just 15mm to the floor height. The advantage of such a thin overlay technology is that it can offer the best of both previous retrofit UFH technologies: quick installation time - between 24 and 48 hours - depending on room size, lower total system cost for the homeowner and a minimal impact on a room’s height. What’s more, with a completed installation height of 15mm, the pipes are much closer to the finished surface. Therefore, the system can operate at an even lower temperature while still achieving the same level of radiant heat as other systems. This is because heat has less distance and material to travel through. If combined with renewable technologies such as a ground or air source heat pump, then a thin overlay system will cost even less to run. No room height is lost enquiry number 152


HPM April 2015
To see the actual publication please follow the link above