Boreholes

This section provides details of an example project featuring a cascaded ground source heat pump system fed by a borehole ground array.

We have provided schematic drawings, example costs and a real-life case study to showcase how a cascaded ground source heat pump system architecture designed by Kensa can effectively meet a high commercial heating and hot water load.

For more information, call sales on 0845 680 4328.

Schematic drawing*

*For illustrative purposes only

Costed example

Cascaded system utilising boreholesHeat pump architecture
Heat pump architectureCascaded central plant
Total heat pump capacity120kW
Equipment type3x 45kW Plant Rooms
Design conditions0/50°C
Potable DHW tempSpace heating only
Integral immersion heatersNo
Ground array typeBoreholes
Boreholes required*2700mtrs
Land area required2000sq/m
Equipment supply costs**£75-90K
Borehole installation, drilling & trenching costs***£142-145K
LPG external costs & boiler equipment£15K
Total 20 year NDRHI funding****£350-500K
Estimated heat pump 20 year running costs*****£350-400K
Estimated LPG running costs******£450-550K
Heat pump lifetime expectancyHeat pump 20 years - pond mats 80 years
Heat pump annual servicingNot required
Projected carbon saving800 tonnes
*Boreholes based on average ground conductivity
**A cost range is depicted here as every project is different and can contain more design features than shown in this example
***Installation costs for external kit only (costs to install internals equivalent to a traditional system)
****NDRHI is a 20 year index linked funding stream which assumes inflation at 3%
*****Based on electric at 15p/kW/hr and COP of 3
******Based on LPG at 40p litre and 85% efficiency

Case Study: Charlestown School

Located next to a busy railway line this school required an efficient heating and cooling system that could operate all year round. The solution was to install an 80 kW cascaded ground source heat pump system connected to ten boreholes located underneath adjacent playing fields. Overall heating costs have been reduced by 75%.

Key facts:

  • Retrofit installation of 1960s building;
  • Cascaded ground source heat pump system;
  • 80kW Kensa Plantroom heat pumps;
  • Providing heating and cooling;
  • 10x boreholes under playing field;
  • 75% reduction in heating costs.
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