Danfoss ground-source heat pump exceeds expectations
Data for a full year, including the harsh Winter of 2010/11 have shown that a heat pump at a school in Lancashire performed considerably better than expected. The Danfoss unit at Bowland High School in Grindleton achieved an average COP of 3.39, well ahead of the predicted 3.08.
The unit is a DHP-L 10 kW 3-phase unit with a 100 litre buffer tank. It heats the 187 m2 single-storey building via radiators and draws heat from the ground via two 250 m loops at a depth of a metre in an adjacent field.
As part of the project, the newly built music block has block cavity walls with 100 mm of insulation to achieve a U-value of 0.2 W/m2 K. The profiled metal deck roof is also highly insulated.
The system was specified by Andrew Kells, a mechanical design engineer with Lancashire County Council. A grant from the Low Carbon Buildings Programme helped with the cost of the system. Another reason for installing a heat pump was that the school was a hundred metres from the road and the cost of a new gas connection for this building would have been very expensive.
