Ground source heat pumps are fully electric heating solutions for homes. The heating pump absorbs low-grade energy from the ground and compresses it into high-grade useable heat. The heat is then delivered through a distribution system, such as radiators or underfloor heating, for reliable heating and hot water through the seasons. 

Ground source heat pumps are an extremely energy efficient heating technology. The system is dependent on the ground temperature, which is typically around 10˚C in the UK, regardless of ambient conditions. This minimal variation gives GSHPs a high seasonal and cold day efficiency.

A typical GSHP system consists of an indoor appliance – the heat pump – that is typically located in a storage or utility space. The pump is connected to an outdoor ground array – a long loop of fluid-filled plastic pipe buried in the ground – and the indoor heating system.  

A liquid is pumped through the system, and as heat naturally flows from warmer to cooler places, it is constantly warmed by the ground’s low-grade heat. The energy absorbed from the ground heats the liquid and turns it into a gas which is further heated through a compressor. The hot gas then flows into a condenser that delivers the property’s hot water needs. The gas then reverts to a liquid and the cycle begins again. 

Similar to a gas boiler, routine maintenance must be carried out on heat pumps to ensure longevity and efficient operation.  

It’s recommended that as well as complying with warranty requirements, a maintenance/service package is considered. It is important that maintenance is always carried out by an authorised installer or service agent. We recommend performing maintenance at least once a year.  

Fully maintained and serviced, a GSHP has a lifespan of between 15-25 years, whereas gas boilers typically last between 10-15 years.  

GSHPs run on electricity, so costs will naturally vary depending on tariffs and market fluctuations, but they are very energy efficient. A ground source heat pump runs at an efficiency rate of between 300-500%, meaning for every 1kW you put in of electricity you generate 3-5kW of heat energy for your home, while a gas system which operates at 90% efficiency means 1.1kW is needed for 1kW of heat.  

When combined with a well-insulated home to retain heat and other technologies such as solar PV panels, plus factoring in the lifespan, efficiency and low carbon impact of the system, there can be overall cost benefits when compared to a standard gas boiler. 

Find out more about the benefits of a new build home, including energy efficiency, here. 

These heat pumps are fitted inside your home and housed in a storage or utility space, much like a traditional gas boiler. The units can be stand alone or be combined with your hot water tank and vary in size, up to approximately the dimensions of a fridge freezer. The outdoor portion of the technology is installed underground.

At Cala we are well on our way to removing gas from our new homes, and heating pumps will play a major part in our future. We have already begun rolling out heat pump technology on new sites, and this will step up as we move towards our target of all new developments from January 2024 being designed to be gas-free wherever infrastructure allows.