068 HPM 1115

HPM November 2015

Got a story? Ring us on 01732 748041 or e-mail twood@unity-media.com BOILERS:LIGHTCOMMERCIAL A modest investment for peace of mind When commercial boilers are being fitted and maintained, chemical water treatment is often overlooked. Neville Small, sales director at Potterton Commercial, argues this is essential to ensure boiler efficiency and longevity... Water treatment, which should comprise a system clean/flush and regular doses of inhibitor as required, is critical for any commercial heating system, large or small. Even completely new heating systems with new boilers and new pipework will need to be chemically treated. Water contains dissolved atmospheric gases which can all play havoc on a heating system’s components. Failing to invest in appropriate water treatment can result in corrosion and the build-up of lime scale, leading to inefficiencies, poor performance and potential boiler failure after a relatively short period of time. What’s more, scale and debris build up can cause noise in the boiler as well as high temperatures due to little or no flow, which can result in failure of significant parts of the system. EFFICIENCY AND LONGEVITY Systems that are corroded become blocked with sludge and debris, which will cause the boiler to work harder and for longer, as the circulating water is unable to transfer the heat efficiently throughout the system. This drastically reduces energy efficiency, in turn increasing running costs, as well as carbon emissions. Meanwhile, lime scale deposits on heat transfer surfaces can also compromise efficiency, as the boiler has to run hotter for longer. Hard water affects over 60% of England and most commercial heating systems installed in buildings located in the south, east and middle of the UK will be subject to the detrimental effects of lime scale if ignored. Alongside the efficiency benefits, all heating systems will perform better and more reliably with good quality water circulating in them. Corrosion and lime scale have a negative impact on system operation and boiler and component longevity. It might sound sensational, but failing to clean, flush and inhibit a system adequately could mean that the boiler could break down in a matter of months, or even weeks. This, of course, causes unnecessary cost and the inconvenience of system downtime, and can also damage the reputation of the installer and boiler manufacturer. It should also be remembered that in addition to affecting efficiency and performance, poor water treatment can, in some cases, invalidate the boiler manufacturer’s warranty. Despite all the benefits that a good chemical water treatment programme provides, and the fact that the Building Services Research and WWW.HPMMAG.COM Information Association (BSRIA), the Industrial and Commercial Energy Association (ICOM) and leading commercial boiler manufacturers recommend flushing, chemical cleaning and the use of appropriate inhibitors, water treatment isn’t always invested in, either because of a lack of awareness or financial constraints. It might seem like a costly exercise, but an appropriate water treatment programme, in line with the boiler manufacturer’s recommendations can pay dividends, with the results being quite significant. We, therefore, strongly recommend that installers encourage their customers to ensure that the heating systems they are responsible for are being chemically treated. In terms of the processes involved, a chemical clean, ideally in conjunction with a power flush, should be the first step, even if the boiler and pipework are new. If a new boiler is being installed on an old system, we recommend a gentle neutral pH clean four to six weeks prior to the installation, followed by a more aggressive (though still neutral pH) chemical clean over one to two days, along with power flushing. Following this, an initial dose, and ongoing use, of a high-quality inhibitor will prevent corrosion and any further build-up of lime scale, helping to maintain boiler efficiency and extend the life of the system. Any water chemicals used must be in line with the boiler manufacturer’s recommendations, which can usually be found in the installation manual. As inhibitors need be applied on an ongoing basis as required, it is important for the person responsible for maintaining the heating system to be able to find and refer to this information, so take time to point it out at 68 NOVEMBER 2015 HEATING & PLUMBING MONTHLY handover. We know of at least one case where a new commercial boiler, professionally installed in perfect condition, broke down under a year after installation because the incorrect water treatment chemicals were used. We suggest that water quality is routinely checked – simple testing kits are available from companies – and that it becomes part of the maintenance programme. The ongoing testing of water quality can highlight any issues early on, and will indicate if inhibitor levels have depleted, helping to save money in the long run. This approach is again recommended by BSRIA, ICOM and commercial boiler manufacturers. A COMBINED APPROACH Adding central heating filters as part of routine service and maintenance to capture any circulating contaminants within the system can also improve system efficiency and longevity – making it well worth the extra investment. Filters are not a substitute for chemical water treatment, however, as they cannot prevent corrosion from taking place in the first instance, so it needs to be a combined approach. It’s also worth mentioning that commercial boilers with aluminium heat exchangers will require particular care, as the water quality must be near-perfect. Aluminium does not rust or corrode in moist conditions, but instead its surface is protected by a natural layer of aluminium oxide, which prevents the metal below from coming into contact with air and oxygen. The surface cleanliness of aluminium is crucial, and it needs to be free of deposits. In particular the system water’s pH level must be kept between 6.5 and 8.5 and copper levels below 0.3 parts per million. We continue to use a range of materials in the construction of our boilers and we use aluminium and stainless steel heat exchangers. However, if there is a situation where water quality might be compromised, even where chemical water treatment is in place, we would recommend a commercial boiler with a stainless steel heat exchanger. We often see hesitance about spending extra money on water treatment, or even a lack of awareness about how important it is. But when the energy savings, and the positive effect water treatment has on boiler life and reliability are considered building services managers should see it’s well worth the relatively modest investment. enquiry number 132 It doesn’t matter if a heating system is old or new, it still needs to be chemically treated


HPM November 2015
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