Heat Pumps Today

Lochinvar heat pump technology is playing a key part in reducing the carbon emissions at one of England’s leading universities. Aston University turns to Lochinvar for low carbon hot water Info www.mhi-hvac.co.uk Info www.lochinvar.ltd.uk It has provided two Amicus high temperature (HT) air source heat pumps connected to three hot water storage vessels as part of a major upgrade of the domestic hot water system serving the main building of Aston University in Birmingham. Founded in 1895, Aston became the UK’s first college of advanced technology in 1956 and has been a leading institution for practical learning ever since. Last year it announced a new strategy to focus more heavily on engineering, business, and health education – and this has been matched by an ambition to make its buildings good examples of low carbon engineering. The university has already secured ISO 14001 and ISO 5001 certifications and was awarded Eco-campus Platinum status for its environmental and energy management systems. As part of its ongoing improvement programme, it has put www.acrjournal.uk/heat-pumps 23 C A S E S T U D Y will also see the Q-ton system deployed at four other Citadines sites across the capital. Ryan Jules, regional maintenance anager at The Ascott Limited UK, who hired KiPO Consultancy to assist with the key sustainability carbon reduction project, said: “This a significant investment towards meeting both the UK Government and CapitaLand’s Sustainability Master Plan target of a 78 per cent reduction in carbon emissions by 2035, for the UK Government, and by 2030 for CapitaLand.” Martin Craxton, of consulting engineers KiPO, worked closely with Citadines to develop a complete renewable solution for the hotel chain. He commented: "Q-ton is an ideal product for commercial water heating applications. It uses CO 2 , a natural refrigerant with ultra-low global warming potential, to produce hot water ranging from 60-90˚C. Q-ton holds e¢ciencies when operating right up to 70˚C, which is required by the hotel to combat legionella growth. Central London’s atmosphere is now rid of the hotel’s 600 kW of gas-burning emissions. Q-ton holds its capacity down to -7˚C ambient and still provides full operation at -25˚C.” Energy accumulation Unlike water heaters using gas or oil, renewable heating systems are not usually designed for instant hot water. Instead, KiPO designed the system using a method known as energy accumulation to meet the apart’hotel's usage profile and peak load. The heat pump generates the energy, and a thermal store holds the hot water until it is used. Principal contractor Nationwide Air Conditioning installed three Q-ton heat pump units and six 1000-litre storage vessels at ground level while the original gas-fired water heaters at the roof level were still in use. The transition to the new system took just a few hours towards the end of the project, ensuring minimum disruption to the property. Nationwide was supported throughout the installation by the MHIAE specifications team. This included online design, training, system design schematics, a pre-commissioning site visit and assistance with final commissioning. Comparing energy usage In addition, the hotel is equipped with a Q-ton Remote Monitoring System (QRMS), a tool that monitors Q-ton’s operation, provides the team with a quarterly report comparing energy usage and e¢ciencies against gas and electric equivalents and self-analyses to highlight any potential operation or maintenance requirements. Germana Genovese, residence manager at Citadines Holborn-Covent Garden, concluded: "The Q-ton's operation has been perfect, and we're looking forward to seeing how e¢ciently the system works during its first winter compared to the gas boilers we previously had. Everyone needs to do their bit to help achieve the government targets of net zero and we are proud to play our part." Lochinvar’s heat pumps at the heart of a new low carbon system with the university expecting to save more than 20,000kg of CO 2 annually as a result. Stand alone The heat pumps are a low carbon solution that allows the main building to operate independently of Aston’s existing district heating system and they produce flow temperatures up to 63degC. Amicus HT heat pumps use the principle of Communised Vapour Injection to improve both output and e¢ciency. They can achieve a Coe¢cient of Performance (COP) up to 4.4 and are 25% more e¢cient than standard scroll compressor driven systems. They will also operate in outside temperatures as low as -20degC. Amicus heat pumps can be used as stand-alone replacements for conventional heating products or as part of an integrated system providing pre-heated mains cold water to gas-fired condensing boilers, water heaters and bu«er vessels in buildings with large heating or hot water demands. The Aston University system was specified by Alex Hall of Ridge & Partners and installed by Mid-West Mechanical & Electrical Services.