How does a ground source heat pump work?

A ground source heat pump circulates a mixture of water and antifreeze around a loop of pipe – called a ground loop – which is buried in the garden. Heat from the ground is absorbed into this fluid and is pumped through a heat exchanger in the heat pump. Low grade heat is then extracted by the refrigeration system and, after passing through the heat pump compressor, is concentrated into a higher temperature useful heat capable of heating water for the heating and hot water circuits of the house. Ground loop fluid, now cooler, passes back into the ground where it absorbs further energy from the ground in a continuous process while heating is required.

The length of the ground loop depends on the size of your home and the amount of heat you need – longer loops can draw more heat from the ground.

Normally the loop is laid flat, or coiled in trenches about two metres deep, but if there is not enough space in your garden you can install a vertical loop to a depth of up to 100 metres for a typical domestic home.

Heat pumps have some impact on the environment as they need electricity to run, but the heat they extract from the ground, air, or water is constantly being renewed naturally.

The efficiency of a ground source heat pump is measured by a coefficient of performance (CoP) – the amount of heat it produces compared to the amount of electricity needed to run it. A typical CoP for a ground source heat pump is around 3.2 if used with under floor heating (it can be reduced if used with radiators). This means for every unit of electricity used to power the pump, you could get 3.2 units of heat

(information source – Energy Savings Trust)

SGAS Ground & Air Source Heat Pumps Course

This course will give candidates detailed explanations & practical examples of selecting, installing and setting to work air source pumps, ground source pumps, brine circuits (loop, slinky and borehole), and integration to domestic heating and hot water systems.

Completing the course and assessment will allow candidates to apply to an MCS Scheme provider (microgeneration certification scheme) such as NICEIC, NAPIT, ELECSA or CORGI.  Where grant funding is not available for the installation, the course and assessment will allow candidates to notify the installation as a ‘controlled service’ via LBC (Local Building Control) in the usual manner.

The course content includes the following:-

-Heat Pump Principles (ground & air source)

-Regulations & Standards

-Evaporation & Condensation process

-Servicing, Commissioning & Fault Finding

-Ground Source systems & circuits (slinky & borehole)

-Filling & Venting

-Integration with other energy sources

-Buffer Tanks

-Collector and emmitor sizing