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Table 1: Comparison of energy consumption for groundwater cooling scheme
Ìý	Groundwater cooling systems	Vapour compression refrigeration
Cooling required	100 kW for 1 hour	100 kW for 1 hour
Cooling energy output	100 kWh	100 kWh
Dt for groundwater	5 °C	N/a
Cp for water	4.2 kJ/kg °C	N/a
Mass of groundwater needed	17133 kg	N/a
Volume of groundwater needed	1000 m3	N/a
Cost of spentwater	17.1 @ 1.135p/m3 %3D £0.19	N/a
COSP of cooling system	40	2
Energy consumption kWh	100/40%3D2.5	100/3 %3D 33.3
Energy cost@£0.082/kWh	2.5 x 0.0082* %3D £0.205	33.3 x 0.082* %3D £2.73
Total cost	£0.395	£2.73
CO2 emissions assuming 0.43 kg CO2/kWh	1.1 kg CO2	14.3 kg CO2
*from http://www.dti.gov.uk/energy/statistics/publication/prices

Table 2: Heating comparison for different technologies
Ìý	New boiler (condensing)	Air source heat pump	Ground source heat pump
Heating load	100 kWh	100 kWh	100 kWh
Seasonal efficiency	88% from www.sedbuck.co.uk	300% SPF from Hundy, 2004	%2400% SPF from IEA, 1995
Energy input (kWh)	113.6	33	25
Cost of energy p/kWh	3.1 p	8.2 p	8.2 p
Cost of input energy £	£3.52	£2.71	£2.05
CO2 emitted	21.6 kg	14.2 kg	10.75 kg

Table 3: Cooling comparison for different technologies
Ìý	Air source heat pump	Ground source heat pump
Cooling load	100 kWh	100 kWh
Seasonal efficiency	280% SPF	320 % SPF
Energy input (kWh)	35.7	31.25
Cost of energy p/kWh	8.2 p	8.2 p
Cost of input energy £	£2.93	£2.56
CO2 emitted	15.3 kg	13.2 kg

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