120 boreholes serve heat pumps for hospital project
Renewable-energy specialist Econic has commissioned a pair of 50 kW ground-source heat pumps as part of a £9.4 million hospital development in Norwich. The ground collector for the system is said to be the largest of its type installed in the UK. The building sets a landmark for the National Health Service’s progress towards becoming carbon neutral by 2018.
The installation will serve a new mental-health unit at Hellesdon Hospital. Lankelma Green Energy worked with Econic to sink 120 boreholes beneath what is now a car park and landscaped area.
The two companies have developed a method of pushing metre-long sections of steel pipe into the ground using hydraulic rams.
When the required depth is reach, the tubes are withdrawn to leave a 40 mm plastic pipe with a closed end in position.
A 25 mm-diameter pipe is inserted into this larger pipe to create a flow and return path for the heat-transfer fluid.
The boreholes are linked using a network of pipes and manifolds. Finally, a pair of 90 mm-diameter flow and return pipes feed each of the Dimplex heat pumps, which serve underfloor heating.
A 40 kW solar PV array on the roof helps achieve an almost zero-carbon heating system.
The renewable-energy heating system was created with the help of funding from the Low Carbon Building programme.
