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HPM-04-APR-2016

Got a story? Ring us on 01732 748041 or e-mail twood@unity-media.com RENEWABLEENERGIES Savvy cylinder specification so critical Jason Hobson, managing director of Gledhill, explains the options for cylinder specification to maximise the performance of heat pump installations... Energy prices may have dipped but the consumer appetite for renewables hasn’t, with homeowners and private landlords increasingly looking for solutions that will reduce their reliance on the grid and give them long-term protection against rising energy costs. While a number of digressions to the Renewable Heat Incentive (RHI) for biomass in 2015 promoted a surge in applications over the course of the year, heat pump technology continued to build consumer acceptance and now accounts for a total of £22.8 million of RHI payments since the initiative came into force. The quarterly RHI report released by Ofgem in November 2015 documents 1,416 accreditations for air source heat pumps during the last period, with a 341 accreditations for ground source heat pumps (GSHPs), bringing the total number of RHI-approved heat pump installations to 7,100. What these figures portray is that heat pump technology is an energy solution that is growing. In order to build on this growth, however, the sector must ensure that heat pumps are installed appropriately and in a configuration that maximises performance. To achieve this, installations must be designed to meet the specific requirements of individual properties to maximise the SPFs (Seasonal Performance Factors) that determine their efficiency. While 60.4% of RHI-accredited air source heat pump (ASHP) installations and 43.2% of GSHPs have been assessed at the baseline SPF level of 2.5, many are achieving a much better rating. Cylinder selection and performance play a critical role in developing the efficiency and SPF rating of heat pump installations and it is critical to understand the options available and the benefits of each. Unvented cylinders: They provide the ideal WWW.HPMMAG.COM solution for installations that are intended to harness the energy from the heat pump for the domestic hot water system only. However, it’s essential to select a cylinder specifically designed for use with heat pumps in order to underpin performance, maximise energy efficiency and ensure safety. For a hot water-only system, an unvented cylinder is an ideal choice. Incorporating a multi-pass coil heat exchanger manufactured from corrugated stainless steel tube, which provides low pressure drop and high flow rates, the design maximises heat exchange to ensure optimisation of the lower temperatures associated with heat pump technology. Installation of any unvented cylinder with a heat pump must address the risk of legionella. This requirement has been incorporated into the range of unvented cylinders, ensuring the temperature of the stored water regularly reaches 60°C in order to pasteurise the cylinder, thereby avoiding the risk of legionella. Gledhill supplies all unvented heat pump cylinders with an immersion heater and a thermostat, which should be set to bring the immersion heater on at a temperature just below the heat pump maximum, and switch it off at between 60-65°C. This maximises the direct energy extracted by the heat pump, thereby enhancing its efficiency, while ensuring it is safe to use at the tap in-line with guidance from the Hot Water Association. To ensure optimum efficiency, the selected unvented cylinder should also be sized to meet potential hot water demand for the property, based on the number of bathrooms and separate shower rooms, assuming that the heat pump will be the primary energy source for all the property’s hot water requirements. 56 APRIL 2016 HEATING & PLUMBING MONTHLY In retrofit situations space can be a premium, making the introduction of renewable alternatives problematic, but specifying a slimline cylinder with a diameter of 475mm will overcome this. Heat pumps: These can also be used to provide the energy for both hot water and heating and, where this is the requirement, a thermal store is required. Thermal stores also provide the ideal solution for installations where heat pump energy is being used in combination with other heat sources. They provide a simple install and low maintenance option with no discharge pipework, no G3 qualification and no annual service or safety check requirement. A 3kW immersion heater for boost and emergency back-up for both heating and hot water also enhances safety and performance. The thermal store provides safe and efficient means of capturing the heat and energy generated from the heat pumps. The energy generated by the heat pump is fed directly into the store for use when needed, providing on-demand heating and domestic hot water generated via mains cold water passing through the highly efficient plate heat exchanger. The thermal store then acts as a buffer, allowing the heat pump to run longer without cycling, enhancing both the financial and carbon reduction benefits. Installers can have a big part to play in making heat pump technology even more popular among homeowners, allowing them to reap the benefits of significant energy and cost savings. By keeping informed of the latest information on products, their features and benefits, installers can keep abreast of innovations and their relevance for specific installations. enquiry number 138 Now with 7 years warranty* cylinders/tanks. Available in split and monobloc types, 3kW ~ 16kW, and a 16kW high temperature split. Complete with simple to use controller and online user videos. Therma V the homeowners choice. lower carbon emissions email: HVAC.marketing@lge.com Please Note: This product contains Fluorinated Greenhouse Gases. Model shown 3kW monobloc. *subject to terms Follow us @LGUK_B2B enquiry number 337


HPM-04-APR-2016
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