Case Study

Mill Farm GSHP reduces carbon footprint by 76% 

With this case study, isoenergy updated Mill Farm with a GSHP, which uses running water from the close-by River Greet to power the heat pump system. 


Property type: Residential 

Technologies installed: Heat pump  

Collector type: Ground 

Size (kW): 25kW   

New/retrofit: Retrofit   

Brand: CTC 

The recommended solution:   

Mill Farm is a Grade II Listed residential property in Nottinghamshire. The property was previously heated by an LPG-fired gas boiler until the owner decided to replace the old carbon-heavy system with a modern ground source heat pump system. 

The River Greet runs right past the property which meant that the running water could be used as the source of energy required for the heat pump system. An 800m array of coiled plastic pipes was submerged in the river, which is connected to a manifold. From the manifold run two flow and return pipes to a 25kW CTC ground source heat pump. With the heat pump are two 500L buffer tanks, containing ample storage for both the heating and hot water. 

Key features:   

25kW CTC ground source heat pump, 500L Cordivari heating buffer tank, 500L Joule hot water tank. 


The new system completely displaces the old fossil-fuel heating, providing all the heating and hot water required all year round. 

Now that the system has been commissioned, the owner will be able to enjoy lower heating costs, a more comfortable level of heat and rest safe in the knowledge that their carbon footprint has been significantly reduced by over 76%.