Ground & Water Source Heat Pumps – Royal Festival Hall

This article below is incorrect, given that water source heat pumps have been used in Britain since 1945, with the Royal Festival Hall in London being heated by a heat pump taking heat from the River Thames in 1951.:

Excerpt from David Banks, Introduction to Thermogeology: Ground source heating and cooling. Second Edition, Blackwell (2012)

Exclusive: Renewable energy from rivers and lakes could replace gas in homes ( Independent, Sunday March 25th)

http://www.independent.co.uk/environment/climate-change/exclusive-renewable-energy-from-rivers-and-lakes-could-replace-gas-in-homes-9210277.html

Millions of homes across the UK could be heated using a carbon-free technology that draws energy from rivers and lakes in a revolutionary system that could reduce household bills by 20 per cent.

The Energy Secretary, Ed Davey, has described the development as “game changing” in relation to Britain’s need for renewable energy against the backdrop of insecurity in Russia, which supplies much of Europe’s gas, and the political row at home over soaring fuel bills.

In the first system of its kind in the UK, a heat pump in the Thames will provide hot water for radiators, showers and taps in nearly 150 homes and a 140-room hotel and conference centre in south London, saving 500 tons of carbon emissions from being released every year into the atmosphere……….”

Actually, it was a gas fired heat pump, the Merlin engine was used as a gas engine, and not converted as a compressor:

“http://www.architectsjournal.co.uk/home/rolls-royce-performance/181204.article

In the case of the Royal Festival Hall, water from the Thames was drawn through a centrifugal pump installed below Charing Cross Bridge at a rate of 1,800 gallons a minute to vaporize a refrigerant at low pressure.

Centrifugal compressors were driven at speeds of up to 17,500rpm by two 12-cylinder Rolls-Royce Merlin aircraft engines, converted to run on town gas with specially designed components that allowed for compactness of plant.

In this way, the heat of the primary fuel was supplemented by the latent energy taken from the river. By making use of the heat dissipated from the exhaust of the engines, as much heat energy as possible was abstracted.

The plant was versatile and could quickly be switched over to operate in a cooling mode. It was intended that the full operational data of the 7,600 kilowatt system was to be assessed after a year, with the additional benefit that it would serve the whole festival complex to make it economically viable against the cost of town gas. According to the plant engineer’s notes, the system worked.

When the exhibition was over, however, a new government assetstripped the site and with it went the demonstration heat pump.

Two professors of building science at Strathclyde University, Markus and Morris, writing in 1980, quoted earlier pronouncements that the energy requirements had been grossly overestimated and the heat pump grossly oversized. They believed that ‘a more favourable situation would have existed had the heat pump been designed to have an output based on the cooling load, rather than the heating load’.