68 HPM 0416

HPM-04-APR-2016

Got a story? Ring us on 01732 748041 or e-mail twood@unity-media.com UNDERFLOORHEATING Efficiency, comfort and ease of use Franz Huelle, technical manager of building technologies at REHAU, examines the challenges of getting it right with underfloor heating controls... The key drivers for consumers choosing underfloor heating (UFH) – and for builders and developers specifying it on their projects – remain efficiency, comfort and cost. The requirement is invariably to deliver warmth or cooling with low running costs at an acceptable capital outlay. Lately, a new driver has grown in importance though – ease of use for the end user. Why then, is there still not greater emphasis on the design and specification of UFH controls? After all, it is these which largely dictate the performance of the system, yet they are far too often treated as an add-on or a fudge and generally have to be installed by an electrician rather than by the installer who fitted the floor system. OPTIMUM COMPATIBILITY I recognise that there are controls experts in this industry who supply solutions specifically for UFH systems. While these are always a better option than generic heating controls, they are not generally bespoke to the individual floor systems so the challenge for the installer is still to ensure optimum compatibility between the two. I know, given enough technical knowhow, that it is always possible to achieve a certain degree of compatibility and to get any controls system talking to any heat source or pump, but with UFH, that isn’t always the best solution for the consumer in terms of either efficiency or comfort. Instead, I’m a great advocate for floor and controls system which are designed and proven to work together in the best possible way and are supplied and supported by a single supplier. In fact, I would argue that these are also even better if they can be installed by the heating engineer so that he is responsible for the whole project, rather than by an electrician working at a different time on site. This not only generally speeds up the installation but, in my experience, also reduces the call backs for the heating engineer later on. Of course, many control systems don’t allow for this because they require not only complex but also mains voltage wiring, but there are options coming onto the market now with easy low voltage wiring and even a choice of wired or wireless thermostats which make things a lot easier. In most domestic projects, it is the fact that the controls are required to optimise the efficiency and comfort levels from what are essentially two separate installations which often causes the issues. Typically, there will still be WWW.HPMMAG.COM REHAU's new NEA controls are suitable for residential and commercial projects UFH on the ground floor and radiators on the upper floors so a different software set up is required within the controls and this can be very testing. At the same time, these two effectively separate installations can be talking to any type of heat source or pump and the controls system needs to be able to adapt to the differences between the modern high efficiency pumps and traditional older style versions. It is true that lots of stand-alone control 68 APRIL 2016 HEATING & PLUMBING MONTHLY systems can function perfectly adequately with both underfloor and radiators and can work with a broad spread of different pumps, but what they often can’t do is optimise the system efficiency at the same time. And surely in that respect they fail on what is a key requirement – delivering maximum efficiency for the consumer. There are integrated control systems available now which are actually clever enough to ‘learn’ the consumer’s habits and operate so that the underfloor system slowly reaches the required temperature in advance of the requirement being triggered – eliminating the peaks and troughs and unnecessary boiler cycling which is so wasteful of energy, and these should surely become the norm. Lots of the current advances in the controls sector are of course also being driven by the requirement for remote access – it’s probably surprised some within the industry just how quickly ‘controlling your home from your phone’ has gone from niche to mainstream and what we’re witnessing now is a real rush to catch up. Again, I don’t think it should just be about crowbarring this functionality into an existing controls solution but instead designing something new which has remote access built in. The market is moving quickly and it’s very positive to see so much innovation taking place, but we should never lose sight of the fact that, from the consumer’s point of view, it’s essentially just about efficiency, comfort, cost and more recently, ease of use. enquiry number 145 REHAU's NEA controls can be installed by the heating engineer using low voltage wiring


HPM-04-APR-2016
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