GSHP system delivers 2.5 MW of heating and cooling
The ground-source heat-pump system at Churchill Hospital in Oxford, thought to be the largest in Europe, includes Ciat Ozonair heat pumps and dry-air coolers. Eight heat pumps can provide over 2.5 MW of heating and cooling. There is space for another unit to increase the capacity to over 3 MW.
Haden Young’s Midlands and southern regions worked in a joint venture with Alfred McAlpine and Impreglio to build the complex. Oxford Radcliffe Hospitals NHS Trust decreed at the outset that these new facilities should be exemplars of energy-efficient, low-carbon design.
The backbone of the solution is a ground-source heat-pump system using water to collect and return heat from boreholes to serve the heat pumps. The dry-air coolers will assist the borehole array at times of high load.
There are some 240 boreholes, each 100 m deep, through which water is pumped in a closed loop through about 56 km of pipe.
Haden Young estimates that COPs/EERs of up to six will be achieved for heating/cooling, enabling the building to achieve an annual energy use of 38 GJ/100 m3 —substantially less than the maximum target of 55 GJ/100 m3 set by the NHS for new hospital developments.
