Across the UK, more and more homeowners are searching for ways to heat their homes that are not only cost-effective but also sustainable. Though there are many choices, heat pumps have quickly become one of the most popular solutions. They provide a reliable, low-carbon alternative to traditional gas or oil boilers, while helping households reduce their environmental impact.
But there are two main types of heat pump: air source and ground source. So what is the difference between air source and ground source heat pumps? Both systems provide a reliable, low-carbon alternative to traditional gas or oil boilers, offering major savings on energy bills and helping reduce your household’s carbon footprint. However, they differ in how they work, how much they cost, and what’s required for installation.
At Adlår, our in-house team specialises in designing and installing air source heat pump systems tailored to the unique needs of UK homes. From compact urban properties to large rural builds, we work with homeowners to find the most efficient and cost-effective option. Here, we’ll break down air source vs. ground source heat pumps clearly, compare costs, and explain how Adlår can help you make the switch with confidence.
Air Source vs Ground Source Heat Pumps – Quick Comparison
Here’s a quick side-by-side look at the key differences:
Feature | Air Source Heat Pump | Ground Source Heat Pump |
Heat Source | Outside air | Underground heat |
Installation | Quick and simple (1–2 days) | Requires digging or boreholes |
Upfront Cost | £10,000–£13,000 (before grant) | £18,000–£25,000 (before grant) |
Efficiency (SCOP) | 3.0 – 4.0 | 4.0 – 5.0 |
Space Needed | Minimal outdoor space | Large garden or land required |
Best For | Most UK homes | New builds or rural properties |
The main difference: Air source systems draw heat from the air, while ground source systems extract heat from underground pipes.
How Do Air Source and Ground Source Heat Pumps Work?
Air Source Heat Pump (ASHP)
An air source heat pump uses a fan to absorb heat from the outside air. Even in cold temperatures, it can convert this heat into energy to warm your home and hot water system. It’s typically mounted on an external wall or in the garden and works efficiently in the UK climate — even down to -15°C.
Ground Source Heat Pump (GSHP)
A ground source heat pump collects heat from underground via looped pipes buried in the garden or under the lawn. The earth maintains a steady temperature year-round, which allows these systems to run with higher efficiency — especially in colder months.
In short: Air source heat pumps are easier to install, while ground source systems offer slightly higher efficiency.
Installation Requirements: What’s the Difference?
Air Source Heat Pumps
- Fast install: Typically completed in 1–2 days
- Minimal disruption: Outdoor unit connected to an indoor hot water cylinder
- Compact: Requires only small external space (wall or ground)
At Adlår, we complete most ASHP installations within 48 hours — no subcontractors, no delays.
Ground Source Heat Pumps
- More complex: Requires trench digging or vertical boreholes
- Takes longer: Installation can take 1–2 weeks
- Needs space: Suitable only for homes with large gardens or land
“Air source heat pumps are quicker and easier to install than ground source systems, which require digging and more time.”
Efficiency and Performance Comparison
Ground Source Heat Pumps: Higher Efficiency
Thanks to stable underground temperatures, ground source systems achieve higher Seasonal Coefficients of Performance (SCOPs) — typically 4.0 to 5.0. That means for every 1kWh of electricity used, they can produce up to 5kWh of heat.
Air Source Heat Pumps: Still Highly Efficient
Modern ASHPs, especially Adlår’s dual heat pump system, achieve SCOPs between 3.0 and 4.0, which is more than enough for most UK homes — even in colder regions.
Real-world performance: The difference in efficiency often doesn’t justify the much higher cost and complexity of a ground source system — especially for existing homes.
Cost Comparison – Upfront and Ongoing Costs
Upfront Costs (Before Grants)
- Air Source: £10,000–£13,000
- Ground Source: £18,000–£25,000
Government Incentives: The Boiler Upgrade Scheme
- Both systems are eligible for the £7,500 heat pump grant through the Boiler Upgrade Scheme
- This significantly reduces your out-of-pocket cost
After grant:
- Air source system: As low as £2,500–£5,500
- Ground source system: Still around £10,000–£17,500
Running Costs
Ground source systems can be slightly cheaper to run due to their higher efficiency — but for many households, the difference in running costs is outweighed by the higher upfront investment.
“Air source heat pumps are generally cheaper to install than ground source systems, especially after applying the £7,500 heat pump grant.”
Which Heat Pump Is Right for Your Home?
Choosing between air and ground source systems depends on your property, budget, and priorities.
If you… | Then Choose… |
Live in an urban or small property | Air Source |
Have a large garden or rural site | Ground Source |
Want fast installation with low cost | Air Source |
Are building a new custom home | Ground Source (if planned in) |
Prioritise maximum long-term efficiency | Ground Source |
Want a balance of value + performance | Adlår’s Dual Air Source |
Why Adlår Recommends Air Source Heat Pumps
At Adlår Castra UK, we specialise in high-performance air source heat pumps — and here’s why:
Designed for the UK Climate
Modern systems work in cold weather and adapt to seasonal temperature changes automatically using smart heat curves.
Faster, Simpler Installation
Our expert in-house team installs most systems within 1–2 days, with minimal disruption to your home or routine.
Lower Cost, Greater Comfort
With direct manufacturer pricing, smart controls, and a Comfort Guarantee, our systems offer superior value without compromise.
We believe that for most UK homes, air source is the smarter choice — especially when combined with our award-winning dual system design.
FAQs About Air Source vs. Ground Source Heat Pumps
Q: Which is better – air source or ground source heat pump?
A: It depends on your property. Ground source systems are more efficient, but air source heat pumps are more affordable and easier to install.
Q: Can I get a heat pump grant in the UK?
A: Yes – both systems qualify for the £7,500 Boiler Upgrade Scheme grant in 2025. Adlår handles the full application process for you.
Q: Do ground source heat pumps need a big garden?
A: Yes – you’ll need space for buried pipework or vertical boreholes, which is not practical for small urban homes.
Q: Are air source heat pumps noisy?
A: No – modern systems like Adlår’s are whisper-quiet, designed for suburban and residential use without disruption.
Q: Is it worth installing a heat pump in the UK?
A: Absolutely. With rising energy prices and government incentives, heat pumps offer long-term savings and environmental benefits.
Making the Right Choice
Both air and ground source heat pumps offer incredible benefits, but for most UK homeowners, the answer is simple:
- Air source systems are cheaper, quicker to install, and ideal for standard UK homes
- Ground source systems offer maximum efficiency but require space and higher upfront investment
At Adlår, we help you make the right choice based on your home, your goals, and your budget. Our expert team will guide you through the process — from grant application to final installation.
Not sure which system is right for your home? Get expert advice from Adlår’s in-house heat pump team.
Book your free home survey and get a fixed quote — including full grant support.
