WWW.HPMMAG.COM Heat recovery: the future in homes? Domestic heat recovery products can help to reduce fuel bills and increase comfort, and they also improve new build SAP scores. Jon Cockburn, head of marketing at Heatrae Sadia, explains more... The Baxi Avanti Plus Combi boiler For your chance to win this prize, simply enquire to answer A or B in response to this question: Baxi’s Avanti Plus Combi boiler is available in which outputs? A: 24, 28, 35 and 39kW B: 26, 29, 33 and 37kW Baxi has launched the new Avanta range of domestic boilers and accessories, previously known as Remeha Avanta. The Baxi Avanta boiler range is exclusively available through independent merchants and remains as reliable and efficient as ever, with the added benefit of Baxi’s award-winning service and support. The Avanta range comprises the Avanta Exclusive Combi, the Avanta Plus Combi, the Avanta Plus System boiler and the Avanta Heat Only boiler. On offer as a prize is the Avanta Plus Combi boiler, a versatile, compact boiler, available in 24, 28, 35 and 39kW outputs to provide highly efficient heat and hot water. PRIZE 7 Answer A 129 REMEMBER: enter all 12 competitions, and you could win the grand prize - the lot! Answer B 130 HPM’s Festive giveaway PRIZE 7 Got a story? Ring us on 01732 748041 or e-mail twood@unity-media.com SPECIALREPORT In simple terms, a heat recovery system collects and reuses waste heat from an HVAC system or a heat-generating piece of equipment - whereas ordinarily this would be lost, and hence wasted. In line with the UK’s carbon emission reduction targets, heat recovery has already become fairly commonplace in the industrial sector. In manufacturing environments it is not unusual to find the waste heat generated by boilers, dryers, ventilation systems, compressors and refrigeration plant being captured and put to good use, for example for space or water heating or process heating and drying. RECOVERING HEAT We are now seeing the concept being translated to the domestic market, most notably in the form of shower heat recovery, where useful heat is recovered from discharged waste water, and mechanical ventilation and heat recovery, where heat from the outgoing air is captured and transferred to the incoming supply. These heat recovery products can help householders to reduce their energy costs, and new build developers to improve their SAP (Standard Assessment Procedure) scores. A shower heat recovery unit (SHRU) transfers useful heat from discharged waste water to the incoming cold mains water supply. SHRUs generally comprise a length of pipe within a pipe (known as a pipe-in-pipe design), which forms part of the vertical section of the waste drain pipe leading to the soil pipe. Meanwhile, mechanical ventilation and heat recovery (MVHR) systems exchange stale air for fresh air, and recover heat in the process. Every property needs fresh air to come in from outside so that the occupants can have good indoor air quality. It’s also vital that stale, damp air and pollutants are removed to protect the health of the people living in the dwelling, as well as the integrity of the building. The way our homes were built in the past meant that they leaked air at the connection points of the walls, floors and roofs, and cracks were always visible around windows and doors. All these openings ensured that large volumes of air moved in and out, and the air content of the home was refreshed regularly. But while this ensured very good, much-needed, ventilation, a lot of heat was lost. This is of course still the situation in many existing UK dwellings, but today any new home is generally constructed under the principles of ‘fabric first’, which ensures that the building’s envelope is thermally efficient, well-insulated and airtight to reduce heat loss. But as modern homes become evermore airtight, they also need to be well ventilated, but cost-effectively and efficiently. Hence ventilation systems with energy saving heat recovery are an increasing feature of new build homes. MVHR systems are generally fitted in a loft, eaves, ceiling void, kitchen/utility cupboard or garage, and comprise a heat exchanger and ducting system. Providing continuous air supply and extraction, they remove contaminated, wet air from frequently wet rooms such as kitchens, utility rooms, washrooms and bathrooms, and then recycle the heat into the fresh air supply going into the other living areas. Some MVHR products include a summer bypass valve, which, when automatically activated, diverts incoming air away from the heat exchanger. This prevents warm air being further heated on the hotter days of the year, which helps towards reducing the risk of overheating. APPLICABILITY So far, heat recovery products have primarily been installed in new build developments, largely driven by the Building Regulations and the fact they can help to significantly improve SAP scores, cost-effectively. Heat recovery products can, however, also be fitted in existing dwellings to reduce energy bills and increase comfort. When fitted retrospectively, running costs can deliver savings which are comparable with solar thermal. Heat recovery has certainly proven its worth in the industrial sector, and with domestic solutions such as shower and mechanical ventilation heat recovery being capable of reducing energy and carbon emissions, easily and cost-effectively, we anticipate that it will soon be a fe ature of many homes. 26 DECEMBER 2013 HEATING & PLUMBING MONTHLY enquiry number 128 The Advance MVHR system from Heatrae Sadia is ideal where space - and budgets - are tight
HPM December 2013
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