Greenest ever chiller lands at Westminster
Britain’s largest ever hydrocarbon refrigerant chiller for a building services application is installed and working well at the historic Church House building in Westminster close to the Houses of Parliament.
The 600kW air-cooled water chiller is part of the new EHS range of hydrocarbon (HC) chillers developed by natural refrigerant specialist Earthcare Products.
These are the first air-cooled chillers operating on natural hydrocarbon (HC) refrigerants to deliver very large cooling outputs – the largest model in the range offers 1,030kW.
HC chillers have been available on the UK market since 1995, but their capacities were previously limited to around 200kW. Over the last three years, Earthcare has been developing larger sizes to extend the application of hydrocarbon environmentally benign refrigerants.
The original Church House was built to commemorate Queen Victoria’s golden jubilee and the current building was opened by King George VI in 1940. It hosted the first meetings of the fledgling United Nations in 1945 and was also requisitioned by Winston Churchill as a temporary home for Parliament during the war because it emerged almost unscathed from a direct bomb strike only a few months after it was opened.
The Earthcare chiller was specified by Max Fordham consulting engineers and the installation, carried out by AMEC, involved closing two roads close to Westminster Abbey on a Saturday morning, diverting two bus routes and organising 12 vehicles to get the crane into position for siting the chiller.
However, the long-term pay back, both financially to Church House and in reduced environmental impact, will more than offset all the capital, installation and disruption costs, according to Earthcare’s managing director Nicholas Cox.
“This installation is a significant milestone in the history of the air conditioning industry,” he said. “We have battled against a series of obstacles created by opponents of natural refrigerants over the past decade, but the development and successful deployment of such a large hydrocarbon chiller in this prestigious location proves the doubters wrong.”
Dream ticket
He explained that minimum environmental impact has been achieved by the “dream-ticket” combination of natural refrigerants and optimal energy efficiency. The EHS range was designed within the constraints of the EU’s BAT (Best Available Technology) protocol and uses the HC refrigerant R290, which is the ideal replacement for R22 with the lowest global warming potential.
“Indirect global warming is reduced by maximising energy efficiency through a combination of factors including the favourable thermodynamic characteristics of HCs, the use of subcooling circuits, which improve coefficient of performance (COP), and floating head pressure control that allows the condensing temperature to float as low as 20°C if ambient conditions allow, instead of the normal 40°C. This is particularly beneficial for chillers that operate year round or at night when ambient temperatures are lower,” explained Mr Cox.
“The combined effect of these energy efficiency measures will result in a potential energy saving in excess of 50% relative to chillers that operate year round without these energy saving features. We predict further improvements to the range when we finish development of our vapour injection economised screw initiative” said Mr Cox.
Earthcare believes that there will be increased demand for this type of solution because until now specifiers and users of screw compressor chillers have been restricted to choosing between expensive ammonia chillers or HFC chillers.
“With both government departments and large corporations increasingly looking for cost effective alternatives to HFCs, this project is a practical demonstration that natural refrigerants can offer cost effective and practical solutions across the whole range of building services applications,” said Mr Cox.
www.earthcareproducts.co.uk