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HPM November 2015

BOILERS:LIGHTCOMMERCIAL Cascade boilers should hold no fear Light commercial applications can provide installers with a business opportunty. Alister Maclachlan, product director at Vokèra, takes a look at how installers can use a cascade boiler system to expand into this market area... For many small businesses and organisations, which we would class as light commercial operations, simply installing a higher efficiency heating system can lead to significant cost savings. For heating engineers, the installation process is similar to working on a residential installation, meaning that this market does present a viable business opportunity. Large-capacity system boilers are available that have familiar characteristics to domestic boilers, and can be installed alongside an existing or new hot water cylinder, or solar thermal cylinder, or alternatively can be fitted as a heat only appliance. A heat only option could be the best solution for a number of light commercial applications, where the demand for hot water is relatively low, for example, just washing up, or hot water for hand washing. COST EFFECTIVE ALTERNATIVE Where renewable technologies are not a viable solution, traditional light commercial gas boilers remain a cost effective alternative. The commercial boiler market has seen a huge amount of research and development over the past few years with modern boilers being designed to offer effective hot water and heating delivery as well reduced energy consumption. For example, we offer the Verve 47kW system boiler. This appliance offers a 90% efficiency rating that can lead to reduced running costs of up to 35%. Installers will find that the internal components, electronic regulation functions and the heat engine are very similar to Vokèra domestic boilers. With a relatively light lift weight of 39kg for a high powered appliance, this type of boiler delivers both the high performance and the capacity needed for small commercial premises coupled with a design that’s familiar to many, making it very straightforward to install. Ensuring a streamlined and efficient installation is a key consideration when upgrading a boiler in light commercial projects. For small businesses, time is precious so it is important to ensure the new boiler can be easily retrofitted with minimal downtime to the occupants. Not so long ago, installers had little choice in respect of flueing options, when it came to a light commercial appliance. Today, it’s different. Modern wall-hung gas boilers with fan assisted flues, now allow greater flexibility when it comes to choosing boiler location and flue termination. Again, the Verve represents a good example of this type of solution. It is certified for a variety of flue configurations with the typical arrangements usually being concentric or parallel. For added versatility, it can also be certified for use with a flexible flue liner, which can be extremely useful if an existing chimney is the only practical route for the flue system. Another important element with light commercial boilers is the capability for installation in a cascade or modular system. Sometimes, in small commercial properties, the output of one boiler might not be enough to power the whole site. In these instances, boilers, can be installed in a cascade system to provide a greater output up to an output of 200kW. This type of cascade system not only offers a greater heat output, but also allows end-users to achieve better, more efficient control. If the demand within the building is high, then all boilers in the system can be working together, but if the heating requirement drops, each appliance can be individually controlled and turned off to match the lower demand. By controlling the system to meet demand in this way, then the result is greater energy savings for the end-user. If a cascade boiler configuration is combined with a control system, greater efficiency savings can be created for the end-user. Aside from managing the boilers and various zone controls and pumps, controls can also be expanded to include inputs from room sensors, remote controls, an external sensor, and a solar thermal system, if required. An as example, the Vokèra Merlin control solution can manage the firing sequence and output of any boilers in a cascade sequence. It is also capable of regulating a heating programme, and the flow temperature of the boilers using the CAN Bus and OpenTherm communication protocols. Many new control solutions can also be controlled and updated remotely using a modem or PC connection and, while all of this sounds quite sophisticated, the user control is a very simple mode selector and temperature selector which allows occupants to easily modify the required temperature and operation of the system, if desired. HYDRAULIC SEPARATOR It is also a good idea to select a boiler with a hydraulic separator. A high output appliance requires an adequate flow rate of water through the heat exchanger at all times to efficiently transfer the heat it produces. A hydraulic separator is a simple device where fluctuations in the system flow do not affect the flow across the boiler. In essence, the integral boiler pump maintains an adequate flow through the boiler and separator (the separator has a large bore so the velocity through it is slow). On the system side outlet of the separator (it is the same water boiler and system side) there can be many draw offs configured to various zones or circuits, each of which can be controlled separately and individually with its own pump and valves. No matter how many, or in what order the various zones open or close, they have no effect on the flow across the heat exchanger as that is maintained at all times at a suitable rate by the boiler pump. In light commercial projects, it’s possible for installers to provide heating upgrades that deliver substantial efficiency improvements and cost reductions, even where renewables are not an option. This type of project is a perfect for a cascade system which should hold no fear for installers. They can make great use of their existing experience and skills to build their business in new, profitable areas. 66 NOVEMBER 2015 HEATING & PLUMBING MONTHLY WWW.HPMMAG.COM Got a story? Ring us on 01732 748041 or e-mail twood@unity-media.com enquiry number 131 The Verve offers a 90% efficiency rating that can lead to reduced running costs of up to 35%


HPM November 2015
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