Hospital unit combines heat pumps and solar PV energy
Ground-source heat pumps powered by photovoltaic cells are helping to minimise the carbon footprint of a new mental-health unit at Hellesdon Hospital in Norwich.
The PV cells power two 50 kW Dimplex SI50 TE heat pumps with energy drawn from a ground energy collector designed and installed by Econic. This is the largest such collector installed in the UK.
The ground energy collector comprises an extensive manifold system fed from 120 arrays sunk 25 m into the chalk beneath the car park and landscaping area. A rig drove a steel pipe into the ground, which was withdrawn when the required depth was reached to leave a large-diameter closed-end polyethylene pipe in place. A smaller pipe was then inserted into the first to allow the antifreeze to be circulated to extract heat from the ground.
The work was carried out for the Norfolk & Waveney Mental Health NHS Foundation Trust, which received a Government grant of £142 000 for the renewable-energy provisions in the building design.