Air Source vs Ground Source Heat Pump

Last Updated on July 10, 2025

If you’re considering upgrading your heating system, understanding the differences between air source and ground source heat pumps is essential. 

Both technologies offer sustainable, energy-efficient ways to heat your home or business, but they vary significantly in installation, costs, suitability, and performance. 

This guide provides an in-depth comparison to help UK homeowners, landlords, and businesses make an informed choice.

Air Source vs Ground Source Heat Pumps: A Quick Comparison

To help you quickly grasp how air source heat pumps (ASHPs) and ground source heat pumps (GSHPs) differ, here’s a concise comparison table covering the key factors that influence your decision:

How Do Air Source Heat Pumps Work?

Air source heat pumps extract heat from outside air, even in cold weather, and upgrade it to a higher temperature to heat your home and hot water. They work similarly to a fridge in reverse, capturing ambient heat and transferring it indoors using a refrigerant cycle.

Pros of Air Source Heat Pumps:

• Lower upfront installation costs compared to ground source.
  
• Easier and quicker to install.
  
• Suitable for smaller outdoor spaces.
  
• No major groundworks required.
  
• Compatible with existing heating infrastructure in many homes.
  
• Eligible for government incentives like the Boiler Upgrade Scheme.
  

Cons of Air Source Heat Pumps:

• Efficiency drops in extremely cold weather.
  
• External units produce some noise.
  
• Requires regular maintenance to maintain efficiency.
  
• May need larger radiators or underfloor heating for optimal performance.
  

How Do Ground Source Heat Pumps Work?

Ground source heat pumps use underground pipes (ground loops) to absorb heat stored in the earth. The ground maintains a relatively constant temperature year-round, making GSHPs highly efficient at extracting heat regardless of outside air temperature.

Pros of Ground Source Heat Pumps:

• Higher and more consistent efficiency.
  
• Lower running costs over time.
  
• Very quiet operation with no visible outdoor units.
  
• Longer lifespan than air source systems.
  
• Can provide cooling in summer if configured.
  

Cons of Ground Source Heat Pumps:

• High upfront installation cost due to excavation.
  
• Requires sufficient land area for ground loops.
  
• Installation is more disruptive and time-consuming.
  
• Planning permission may be required.
  
• Not suitable for flats or properties without adequate outdoor space.

Air Source Heat Pumps vs Ground Source Heat Pumps: Key Differences

Energy Efficiency

Ground source heat pumps generally outperform air source heat pumps in terms of Coefficient of Performance (COP) because the ground temperature remains stable, typically between 7-13°C, throughout the year. 

According to the Energy Saving Trust, GSHPs can achieve COPs as high as 5, meaning for every unit of electricity used, up to 5 units of heat are generated.

In contrast, air source heat pumps’ efficiency varies with outdoor air temperature, which can drop significantly during winter, reducing performance. The typical COP ranges between 3 and 4. However, advances in ASHP technology have improved cold-weather performance.

Installation Requirements

Air Source Heat Pumps are generally easier and quicker to install compared to ground source systems. The installation involves mounting an external heat pump unit similar in size to a large outdoor air conditioner, usually outside your home in an area with good airflow and minimal obstructions. 

Inside the property, the system connects to your heating distribution network, which often requires a hot water cylinder to store and supply domestic hot water efficiently. The cylinder is essential because heat pumps operate at lower temperatures than traditional boilers, so having a well-insulated hot water tank ensures you have enough hot water when needed.

The typical ASHP installation can take a few days and doesn’t usually require major disruption to your property or garden. 

Moreover, ASHPs can often be integrated with existing radiators or underfloor heating systems, although radiators might need to be larger or low-temperature compatible.

Ground Source Heat Pumps, on the other hand, require more extensive groundwork. Installation involves laying underground pipe loops either horizontally (trenching) or vertically (boreholes) to access stable ground temperatures. 

This excavation process can take several weeks depending on the size of the system and the type of ground loop needed. Because of this, GSHP installations are more disruptive and require adequate outdoor space, making them better suited to larger properties with gardens or commercial sites.

Like ASHPs, GSHPs require a hot water cylinder to provide domestic hot water. Due to the lower temperature output of heat pumps, a well-insulated cylinder is vital for storing and delivering hot water on demand.

In summary, ASHPs offer a faster, less invasive installation, suitable for most UK properties, while GSHPs need significant groundworks and space but deliver high efficiency over the long term.

Installation Cost

Installation costs for ASHPs typically range between £7,000 and £13,000, making them more accessible to most homeowners and landlords. 

GSHPs require extensive groundworks and drilling or trenching, driving costs upwards of £12,000 to £20,000 or more, depending on the size and type of ground loop.

The UK Government’s Boiler Upgrade Scheme supports ASHP installations with grants to reduce these costs for eligible properties.

Installation Costs Comparison

Running Costs

Due to the stable heat source underground, GSHPs generally have lower electricity consumption during operation, reducing energy bills. 

Air source heat pumps, while still efficient, may incur slightly higher running costs during cold spells when the system must work harder.

Electricity prices impact both, but pairing heat pumps with solar PV panels can help reduce net running costs significantly.

Running Costs Comparison

How Do Carbon Emissions Compare?

Heat pumps dramatically reduce carbon emissions compared to conventional fossil fuel boilers. 

According to Ofgem, ASHPs can reduce household carbon emissions by up to 60%, while GSHPs achieve up to 80% reductions, reflecting their greater efficiency.

Carbon Emissions

Heat pumps dramatically reduce carbon emissions compared to conventional fossil fuel boilers. 

According to the Energy Saving Trust, air source heat pumps can typically reduce household carbon emissions by around 50-65%, while ground source heat pumps can achieve even greater reductions of up to 75-80%, due to their higher efficiency and stable heat source.

Maintenance and Servicing Requirements

Both air source heat pumps (ASHPs) and ground source heat pumps (GSHPs) require regular annual servicing to ensure optimal performance and extend their lifespan.

• Air Source Heat Pumps: ASHPs have external components such as fans and compressors exposed to weather, dust, and debris.
  
  This exposure means they typically need more frequent inspections and occasional cleaning of filters and coils. Annual servicing costs for ASHPs usually range between £150 and £300 in the UK. Some minor repairs, like fan replacement or refrigerant top-ups, might add to this cost.
  
• Ground Source Heat Pumps: GSHPs have buried ground loops which experience minimal wear and require less maintenance. However, the indoor components such as the heat pump unit and associated plumbing still require servicing.
  
  Annual maintenance for GSHPs is slightly higher due to the complexity and servicing of the buried system and usually costs between £200 and £350. Additionally, ground loop integrity tests might be needed every few years, which could incur extra costs.
  

Regular maintenance is crucial for both types to maintain efficiency, avoid costly breakdowns, and uphold manufacturer warranties.

Maintenance and Servicing Costs Comparison

What Is the Typical Lifespan of Air Source and Ground Source Heat Pumps?

Heat pumps are a long-term investment, but their expected lifespans vary based on technology, installation quality, and maintenance.

• Air Source Heat Pumps (ASHPs) generally have a lifespan of 15 to 20 years. Their external components, like fans and compressors are exposed to weather conditions, which can affect durability. Regular maintenance helps maximise their service life.
  
• Ground Source Heat Pumps (GSHPs) typically last longer, with an expected lifespan of 20 to 25 years. The underground ground loop system has minimal wear and can last 50+ years, although the indoor heat pump unit requires regular servicing.

Noise Levels

Noise can be an important consideration, especially in residential areas.

• Air Source Heat Pumps produce moderate noise due to their external fan units, usually around 40-60 decibels during operation. This is comparable to a quiet conversation or a normal office environment but can be noticeable, especially if the unit is near living spaces or neighbours.
  
• Ground Source Heat Pumps are very quiet since the heat exchange happens underground, and only the indoor unit operates at low noise levels, generally below 35 decibels. This makes GSHPs ideal for noise-sensitive environments.

What Property Types Are Best Suited?

Air source heat pumps are more flexible for properties with limited outdoor space, including flats and terraced houses, whereas ground source heat pumps need substantial land space and are suited for detached homes, commercial buildings, or rural properties.

Space Requirements

ASHPs need an external unit roughly the size of a small fridge (about 1-2m²) placed where airflow is unobstructed. GSHPs need either vertical boreholes or extensive horizontal pipework underground, requiring significant garden space or land.

Planning Permission 

Planning rules vary locally, but ASHP installations generally do not require planning permission unless the property is in a conservation or listed area. GSHPs often require planning permission due to the impact of excavation works.

Compatible with Existing Heating Systems

Both ASHPs and GSHPs work best with underfloor heating due to their lower operating temperatures, but ASHPs can integrate with upgraded radiator systems. 

Compatibility with existing boilers depends on system design, some heat pumps can work alongside gas or oil boilers for hybrid setups.

Can They Be Paired With Solar Panels?

Yes. Both systems are ideal for pairing with solar PV installations, reducing electricity consumption from the grid. This combination maximises renewable energy use and cuts running costs.

Ready to Switch? Request Your Free Air Source Heat Pump Quote Today!

If you’re ready to take the next step towards a greener, more efficient heating system, Eco Happy is here to help. Our expert team specialises in installing high-quality air source heat pumps tailored to your property’s unique needs.

Request your free, no-obligation air source heat pump quote today and start saving on energy bills while reducing your carbon footprint.

FAQs

1. How do heat pumps perform during power outages?

Most heat pumps require electricity to operate, so during a power outage, heating and hot water will be unavailable unless you have a backup power source like a generator or battery storage system.

Can heat pumps help increase property value in the UK?

Yes. Installing a renewable heating system like an air source or ground source heat pump can improve energy efficiency ratings, making properties more attractive to buyers and potentially increasing market value.

What impact do heat pumps have on home insurance?

Some insurers may require notification of heat pump installations, but many see them as a positive upgrade. It’s advisable to check with your insurer to ensure coverage and possible premium adjustments.

Are there specific insulation standards needed before installing a heat pump?

For optimal performance, UK homes should have good insulation and airtightness. Properties with poor insulation may struggle to maintain heat efficiently, reducing heat pump effectiveness and increasing running costs.

How do heat pumps integrate with smart home systems?

Many modern heat pumps can connect to smart thermostats and home automation systems, allowing precise temperature control, scheduling, and energy usage monitoring to maximise comfort and savings.

Conclusion

Choosing between an air source and ground source heat pump depends on your property’s characteristics, budget, and long-term goals. Air source heat pumps offer a cost-effective, flexible solution with quicker installation and suitability for various property types. 

Ground source heat pumps provide superior efficiency and lower running costs but require a higher upfront investment and adequate outdoor space.

Both systems offer significant carbon savings and the opportunity to future-proof your property’s heating. 

For many UK homeowners and landlords, air source heat pumps present an accessible path to greener energy. By pairing your heat pump with renewable electricity sources, such as solar panels, you can maximise savings and sustainability.

To ensure you choose the best option for your home or business, consult with experts like Eco Happy for personalised advice and competitive quotes.