Renewable Energy Installer December/January 2014 | Page 30

Knowledge: Heat pumps Heated debate Alan Dunn, Husky Heat Pumps’ business development manager, addresses the burning issue of specifying a high or low temperature heat pump umerous brands are now producing high temperature heat pumps therefore negating the need for larger radiators. Is this a good thing? Or is it better to buy a low temperature heat pump and larger radiators? The answer lies in applying the heat pump where it is strongest. Simply put, the lower the temperature the heat pump produces, the more efficient it is. There is a further complication when using high temperature heat pumps and that is that the capacity of the unit has to be bigger, therefore adding cost. But understand this - the higher the temperature the heat pump produces, the lower the output in kW. So why do brands promote high temperature heat pumps? I do struggle to answer this, however, one reason is legionella. The high temperature heat pump can perform this function without the need for an immersion heater which is a good thing on large commercial properties where high temperatures for hot water are needed more often than once per week. This is not enough, however, for a domestic customer to be convinced to purchase a more expensive, high temperature heat pump. N Cool reception: Husky Heat Pumps’ Alan Dunn advises against specifying high temperature heat pumps due to significant extra running costs We see the extra running costs of high temperature heat pumps (using smaller radiators) to be significantly higher than low temperature. In some cases we have seen over double the running costs. It is not a simple case of COP, it is also kW output when running so be careful! Stick to the golden rule and a heat pump will perform well - The lower the temperature the more efficient the heat pump. Simple. COMPETITION WIN one of five Screwdriver sets International hand tool manufacturer Bahco is offering readers of REI a chance to win one of five ‘Easy Change’ 1000V Insulated Ratcheting Screwdriver Sets, incorporating six interchangeable blades. Each set has a retail value of £115 This excellent new product is certified according to IEC 6090 and is suitable for working on live electrical equipment; t
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The screwdriver handle has a 48-tooth non-conductive ratcheting mechanism The blades are 30 per cent slimmer than regular insulated blades, offering better accessibility, for example to sunken screws or spring elements A patented blade release system enables users to change blades safely and easily Blade sizes included in the set are: PH1, PH2, 0.4x2.5, 0.5x3.0, 0.8x4.0 and 1.0x5.5 Bahco hand tools are the preferred choice of thousands of trade professionals worldwide; the brand is renowned for its quality, performance delivery and durability. To enter this free prize draw, email [email protected] with Bahco competition as the subject title. Winners will be drawn at random and announced in the February issue. 30 | www.renewableenergyinstaller.co.uk