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Air source heat pumps vs ground source heat pumps

Air source heat pumps vs ground source heat pumps

So you’re set on a heat pump. Great choice! But should you go for an air source heat pump or a ground source heat pump?

While the two work similarly, they have key differences. Here, we’ll break down all you need to know about air source heat pumps vs ground source heat pumps to help you make a decision.

Air source vs ground source heat pumps: what’s the difference?

Both air source and ground source heat pumps extract warmth from the environment around them.

But air source heat pumps extract that warmth from the air, while ground source heat pumps extract it from the ground, or from water sources.

This can lead to differences in things like efficiency, installation costs, longevity and more.

Let’s take at how they differ when it comes to each of these key factors.

Ground source heat pump vs air source heat pump comparison

As a general rule, air source heat pumps are easier and more cost-effective to install than ground source heat pumps – making them the most popular option for homes and businesses in the UK.

However, ground source heat pumps also have their advantages.

Here’s how they compare on key points.

Upfront costs

Although any heat pump will require substantial upfront investment, air source heat pumps are generally much more affordable.

This is because you won’t have to pay for groundwork and ground arrays as you would have to with a ground source heat pump.

Ease of installation

Similarly, air source heat pumps are much quicker and less disruptive to install.

After all, unlike ground source heat pumps, air source heat pumps are installed above ground – meaning there’s no need for ground arrays like slinky pipe trenches or boreholes.

This is particularly good news for businesses that are looking to retrofit a heat pump, as it makes it more likely they can operate continuously during installation

Efficiency

Both air source and ground source heat pumps are extremely efficient.

However, ground source heat pumps tend to be the most efficient option. While air source heat pumps can reach around 300% efficiency, ground source heat pumps can reach around 400%!

This is because the temperature below-ground will remain much more constant than the temperature of the air.

That said, it’s worth noting that although air source heat pumps may not be quite as efficient as ground source heat pumps, they’re still much more efficient than traditional gas boilers, which can reach only around 98% efficiency at most!

Running costs

As ground source heat pumps are the more efficient option, they tend to have slightly lower running costs.

However, it’s worth noting that both air and ground source heat pumps are cost-effective to run.

Firstly, they use just a small amount of electricity – just 25% of the energy used by an air source heat pump is typically provided by electricity and the rest is generated by the environment through the air.

And secondly, heat pumps require very little maintenance in comparison to traditional boilers, as they have a robust design with minimal moving parts.

Lifespan

Both air source and ground source heat pumps are built to last, with longer lifespans than traditional boilers.

To give you a rough idea, while boilers typically last around 10 to 12 years, heat pumps should last over 20.

Not only that, but they’re a futureproof heating system that won’t be affected as heat decarbonisation moves further up the government’s priority list.

That said, ground source heat pumps have the edge when it comes to longevity, lasting roughly five years longer than air source heat pumps.

Space

For many homes and businesses, space is a deciding factor.

Ground source heat pumps require a significant amount of outdoor space, as the ability to dig trenches or drill boreholes is a prerequisite.

However, once they’ve been installed, you’ll regain all that space, as the ground arrays will be tucked under the ground out of sight.

On the other hand, air source heat pumps require a lot less space, making them an option for many more buildings. But of course, the air source heat pump is located above-ground. Which brings us onto…

Visibility

As air source heat pumps are located above-ground, you’ll be able to see them!

That’s not necessarily a bad thing and there are lots of solutions you can adopt to make your air source heat pump more pleasing to the eye.

However, some people might prefer the fact that ground source heat pumps are mainly located below-ground, out of sight (although bear in mind that the unit itself will still be visible).

With that in mind, ground source heat pumps are typically quieter too.

Air source heat pump

Sustainability

Last but not least, heat pumps are known for being environmentally friendly.

Not only are they a renewable energy source but they also don’t produce emissions – which makes them much better for the environment than traditional boilers.

But which has the edge when it comes to sustainability – air source or ground source heat pumps?

Well, there’s not much in it. However, ground source heat pumps typically use even less electricity than air source heat pumps meaning they probably have the edge – but only just!

That said, the main factor that we believe makes a real difference to the sustainability of both ground and air source heat pumps is the refrigerant you use.

Synthetic refrigerants like HFOs and HFCs are often made up of harmful F-gases that speed up global warming and release harmful forever chemicals known as PFAS into the environment.

On the other hand, natural refrigerants are non-toxic, have very low global warming potential (GWP) and zero ozone depletion potential (ODP), which makes them a vastly cleaner option.

As a certified B Corp, at Clade, we only use natural refrigerants as we understand that they’re the best option for both people and the planet.

Ground source and air source heat pump pros and cons

As you can see, there’s a lot to think about when you’re choosing between a ground source and air source heat pump.

To help you compare the two, here’s a brief summary of their pros and cons.

Air source heat pump advantages

  • More affordable
  • Easier to install
  • Requires less space
  • Suitable for most buildings

Air source heat pump disadvantages

  • Less efficient
  • Higher running costs
  • Visible (above ground)
  • Louder

Ground source heat pump advantages

  • More efficient
  • Lower running costs
  • Quieter
  • Visually unobtrusive
  • Longer lifespan

Ground source heat pump disadvantages

  • High upfront costs
  • Disruptive to install
  • Requires more space

Ground source vs air source heat pump: which is better?

So, which is better: an air or ground source heat pump?

Well, they’re both fantastic options!

After all, both ground and air source heat pumps are efficient, future-proof, eco-friendly and cost-effective to run.

However, at Clade, we believe that air source heat pumps are the best option for most businesses.

Why?

Well, ground source heat pumps may be effective but they also come with high upfront costs and a much more disruptive installation process. Plus, they’re not suitable for all buildings due to the space they require.

On the other hand, air source heat pumps are much more cost-effective, easy to retrofit and suitable for most buildings.

In fact, our latest air source heat pump – the Elm – is designed to be a direct replacement for traditional boilers.

This suddenly puts heat pumps on the cards for thousands of buildings that may not have previously been able to consider making the switch – like listed buildings and healthcare facilities.

Keen to learn more about how your business could benefit from heat pump technology?

At Clade, we exclusively work with air source heat pumps as we believe they’re much more accessible for the majority of people and businesses.

Browse our selection of commercial air source heat pumps or get in touch to find out how we can help.