Heat Pumps Keep the 'RHI-nos' Happy

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Published: 20 November 2014


Heat Pumps Keep the 'RHI-nos' Happy - heat pumps today
It is not everyday that you can talk about rhinoceroses and heat pumps in the same sentence, but Mitsubishi Electric has made it possible with the installation of four Ecodan air source heat pumps at Edinburgh Zoo.

The heat pumps are used to heat the indoor swimming pool of two male, one-horned Indian rhinoceroses in the Scottish zoo. The zoo has been looking for ways to reduce the energy needed to heat the swimming pools without impacting the wellbeing of the animals, known as Samir and Bertus.

The heat pumps replaced an old, inefficient gas boiler, the lifespan of which had come to an end, and have, consequently, reduced their energy bill and emissions by nearly one third. 

Attractive RHI-nos

With the heat pumps installed as a cascade, the zoo qualifies for the non-domestic renewable incentive (RHI) which would contribute about £4,000 to the running costs of the 8.5 kW Ecodan's over twenty years.

The heat pumps deliver renewable heat to the 4m x 4m x 0.5m indoor pool for the rhinos all year round no matter what the outside temperature.

Lothian Gas, from Edinburgh, installed the heat pumps after calculating a 30 kW heat load for the pool, necessitating a 40kW capacity system. The heat pumps ‘tube and tube’ heat exchanger designed to work with and maintain the lower temperatures that enable the heat pumps to be very efficient.

Furthermore, there is a Grundfos pump between the heat pumps and the heat exchanger which circulates water around the system to make sure the response time of the heat pumps is quick. 

Monitoring Efficiency

The Ecodan heat pumps have not travelled far from the manufacturer's factory in Livingston, where Mitsubishi Electric also provided training for the Lothian Gas installation team who, in turn, worked closely with Edinburgh Zoo on the project. In-situ monitoring is important to qualify for the RHI, which meant that the design included an SD card to collect energy use data from the system. 

Commissioned in November 2014, the heat pumps are now successfully provided a heated pool for Samir and Bertus and, judging by their behaviour, they are enjoying their environment. The rhinos can been various forms of 'rhino enrichment',  such as large balls, tractor tyres and logs. 

Their pool is now kept between 28 and 30 degrees celsius by the heat pumps which enables them to swim and wade throughout the year.