46 HPM 0214

HPM February 2014

WWW.HPMMAG.COM Modulation innovation benefits everyone Alister Maclachlan, product director at Vokèra, explains how wider modulation ratios within gas boilers can help installers deliver better heating performance and minimise fuel bills for consumers... 46 Got a story? Ring us on 01732 748041 or e-mail twood@unity-media.com DOMESTICHEATING Many homeowners would like to be part of the ‘green revolution’ but are not yet prepared or able to commit to a renewable space heating system in a new-build or to the insulation improvements needed for retrofit to be an option. SSE is the latest of the six big energy suppliers to announce that it will be cutting its household energy tariffs by 3.5% from March 24, 2014. It is the fifth out of the Big Six energy supply giants to pass on the savings received from the government’s deal to cut green levies. COST OF LIVING CRISIS This is welcome news, but the truth remains that many British households are struggling to cope with a cost of living crisis, where the high price of energy is proving a major contributor. According to the Office for National Statistics (ONS), the rapid rise in the price of energy, with gas up 21% over the last four years, has accounted for the majority of the rise in the UK's consumer prices of 14% in this period. At a time of wages stagnation, the ONS estimates that the share of UK household income going on "essentials", including energy, is up from 28% in 2003 to 36% now. In this context, energy efficiency still remains a top priority for heating manufacturers, installers and their customers. At Vokèra we are continually improving our range to make sure we provide innovative technology to help installers reduce fuel bills and carbon emissions from their customers. SIGNIFICANT INNOVATION Boiler modulation is one of the most significant areas of innovation. A boiler that is capable of reducing its maximum output to its minimum output, will offer a wide modulation, providing a more efficient performance output than a boiler with a narrow modulation. For example, if a boiler has a maximum output of 30kW and a minimum output of 7.7kW its modulation ratio is less than 4:1. Meanwhile, an appliance with a maximum output of 30kW and a minimum output of 3kW has a wider (hence better) modulation ratio of 10:1. Modulation ratios should be a crucial part of the decision making process for installers selecting a boiler. A good modulation ratio reduces constant on/off cycling, improving efficiency and boiler longevity. If a boiler has a high maximum output at 40kW for example, yet only has a modulation ratio of 4:1 it will only be able to modulate down to 10kW. However, when most rooms have reached the required temperature and the radiator’s thermostatic radiator valves have closed, the demand on the boiler will be considerably less than 10kW. This means that the minimum output of the boiler will be higher than it needs to be, so the boiler will constantly switch on and off, leading to fuel inefficiency. This will also lead to unnecessary stress on the boiler’s components and parts. A boiler with a high maximum output and a wide modulation ratio, however, will be able to modulate down to an extremely low output, reducing wear and tear on primary components (fewer on/off cycles increase component longevity) and optimising fuel efficiency. FLOW TEMPERATURE Secondly, an appliance (specifically combis) with a poor modulation ratio will not be able to maintain a stable domestic hot water (DHW) flow temperature at a low flow rate, and might even cause the burner to switch off during operation. This can be a significant issue for end users who prefer showers over baths or for those who require a constant DHW outlet temperature, for example, where there are young children or elderly people in a household, who are at a higher risk of scalding. Our own research has shown that a product with the 10:1 modulation will provide the user FEBRUARY 2014 HEATING & PLUMBING MONTHLY with an approximate saving of 8.5% on space heating consumption, amounting to an estimated saving of £55 in comparison to a 5:1 modulation appliance. In selecting a boiler for a project, installers should remember that performance isn’t just about kW output. Installing a boiler with a high maximum output and a wide modulation ratio will deliver optimal efficiency and comfort for their customers. Installers have a key role to play in ensuring that UK heating systems become more efficient. They are also best-placed to advise consumers on how they can make the best choice to keep their fuel bills as low as possible. Wide modulation ratios offer a range of important benefits. As energy costs continue to take such a large proportion of the household budget, consumers will warm to these new ‘thinking’ boilers which can adapt more readily to their own lifestyle at the same time as they take efficiency to a higher level, and help to keep fuel bills down. enquiry number 131 High modulation ratio Low modulation ratio


HPM February 2014
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