Air Source vs Ground Source Heat Pumps (GSHPs)

by | Dec 6, 2023

Renewable energy is an important element in the fight against climate change and it’s at the forefront to help reach commercial sustainability goals. With so many options available, it’s important to carefully consider each to determine which will be most efficient for you. One such solution is investing in Air Source Heat Pumps (ASHPs) or Ground Source Heat Pumps (GSHPs) – but which pump do you choose?

The Differences between ASHPs and GSHPs

Whilst both ASHPs and GSHPs absorb heat from renewable sources, there are certainly some differences between the two pumps.

Heat Source

The main difference between these heat pumps is where they source their heat from – the ground or the air. Ground source heat pumps use geothermal pockets and naturally heated ground layers, whereas air source heat pumps absorb heat from the outside air. In comparison to traditional gas boiler heating systems, heat pumps have been found to be up to 400% more efficient! What’s more, they also produce 70% less carbon emissions.

Working Conditions

One key benefit of GSHPs over ASHPs is the fact that they can tap into a consistent heat source. The ground remains at a constant temperature between 8°C and 12°C over the year, whereas ASHPs depend on the fluctuating temperature of the air. 

This means, when demand is highest over winter, GSHPs will not experience any spikes in electricity usage. On the other hand, ASHPs will as more electricity is required to extract heat energy from the colder air.

Other Considerations

When it comes to deciding whether to invest in air source or ground source heat pumps, it’s worth noting all the factors that could influence your decision. These include:

Installation Costs

If we don’t take into consideration any government grants, the cost of an ASHP should range between £7,000 and £13,000. However, you can be expected to pay between £14,000 and £19,000 for a GSHP.

Running Costs

As mentioned above, the installation cost of an ASHP is considerably cheaper than a GSHP. However, due to their reduced efficiency in colder conditions, their running costs tend to add up to be considerably more. 

Ground source heat pumps are unaffected by temperature fluctuations, so they can work overnight when operating costs tend to be lower. ASHPs cannot benefit from these time-of-use tariffs because these lower running costs are typically when the air is coldest, meaning more electricity is required to extract the heat.

Available Space

The size of an air source heat pump depends on the property’s heat demand. However, they’re not usually any bigger than your standard air conditioning system. On the other hand, GSHPs need a lot of space. Moreover, excavation work is required to install the system below ground level. If you don’t have much outdoor space available, then vertically installed boreholes may be necessary.

Contact Borehole Solutions

If you want to learn more about air source or ground source heat pumps, then look no further! At Borehole Solutions, we have over two decades of experience in geotechnical drilling solutions for the installation of renewable heat pumps. Give the team a call on 01733 200501 or click here to fill out our contact form.