Air Source vs Ground Source: Which Heat Pump Suits Your Kent or Sussex Home?

Oct 22

3 min read

Switching to a heat pump is one of the most effective ways to cut your heating bills and reduce your carbon footprint. But when it comes to choosing the right system, many homeowners are faced with a key question: air source or ground source?

Both are brilliant renewable heating technologies, but they’re not one-size-fits-all. The right option depends on your home, garden space, budget and long-term energy goals. Let’s break down the differences so you can make an informed choice for your Kent or Sussex property.

How Each Heat Pump Works

Air Source Heat Pumps (ASHPs)These units sit outside your home and draw warmth from the air, even when it’s cold. The captured heat is then compressed and transferred into your home to power radiators, underfloor heating and hot water.

Ground Source Heat Pumps (GSHPs)These systems absorb heat from the ground through a network of buried pipes. The pipes can either be laid horizontally in trenches or vertically in boreholes, depending on the space available. The steady ground temperature makes GSHPs very efficient year-round.

Efficiency and Performance Both systems are far more efficient than a traditional gas or oil boiler, often delivering three or more units of heat for every unit of electricity they use.

Air Source: Typically more efficient in milder temperatures, though performance can dip slightly in very cold weather.
Ground Source: Because the ground maintains a steady temperature, GSHPs tend to offer higher efficiency and consistency, particularly during the colder months.

Installation Requirements

Air Source: Easier and quicker to install, needing just an outdoor unit and connections to your heating system. Perfect if you don’t have much outdoor space.
Ground Source: Requires either land for horizontal trenches or space (and budget) for a borehole. This makes installation more complex but also more discreet once in place.

Cost Considerations

Air Source Heat Pumps are generally cheaper to install, with most domestic systems in the range of £8,000–£16,000.
Ground Source Heat Pumps have higher upfront costs, typically £18,000–£50,000, depending on whether boreholes are needed.

However, GSHPs often deliver lower running costs thanks to their higher efficiency, meaning the extra investment can pay back over time.

Both types are eligible for the Boiler Upgrade Scheme, which offers grants of up to £7,500 to help with installation.

Which Homes Are Best Suited?

Air Source Heat Pumps are ideal if:

You want a more affordable renewable upgrade
You have limited outside space
You live in a typical semi-detached or terraced property

Ground Source Heat Pumps are best suited if:

You have outdoor land for trenches or the ability to drill a borehole
You’re planning a new build or major renovation
You want maximum efficiency and lower running costs in the long term

Our Advice for Kent and Sussex Homeowners

For many households in Kent and Sussex, air source heat pumps are the most practical and cost-effective first step into renewable heating. They’re quicker to install and suit a wide range of property types.

If you’re building from scratch, have a large plot of land, or want to invest in the most efficient system available, ground source heat pumps are a fantastic choice that can deliver exceptional performance for decades.

Not sure which way to go? The best starting point is a proper site survey and heat loss calculation to see which system would give you the best results.