Air Source vs Ground Source Heat Pumps
The real differences in cost, efficiency and installation, and why most Irish homes go for air source.
Grant figures confirmed against SEAI
Air Source vs Ground Source Heat Pumps, Side by Side
Air source vs ground source is the first real decision when moving to a heat pump. Both pull renewable heat into your home and both qualify for the SEAI grant, but they differ sharply on install cost and groundwork. For most Irish homes the answer is air source.
Air source heat pump
€12,000 – €18,000
- Extracts heat from outdoor air
- Lower install cost, no groundwork
- Quick to install, days not weeks
- Well suited to the mild Irish climate
Ground source heat pump
€20,000 – €30,000
- Extracts heat from underground pipes
- Higher efficiency, stable ground temperature
- Needs space for loops or a borehole
- Best on larger rural sites
Cost, Installation and Efficiency in the Irish Climate
The gap is groundwork. An air source heat pump mounts a unit beside the house and connects to your heating, so it installs in a few days for €12,000 to €18,000 before grants. A ground source system needs trenched ground loops or a drilled borehole, which pushes the price to €20,000 to €30,000 and the timeline out by weeks.
Ground source is more efficient because underground temperature stays stable all year, so the system works less hard in the cold. Air source efficiency dips slightly in a hard frost, but Ireland's mild, damp climate rarely gets cold enough for that to matter, which is why air source performs so well here for a fraction of the cost.
Find an installer near youAir Source vs Ground Source, Answered
What is the difference between air source and ground source heat pumps?
An air source heat pump extracts heat from outdoor air through a unit on the wall or ground beside the house. A ground source heat pump extracts heat from underground pipes or a borehole. Air source is cheaper to install, ground source is more efficient over its lifetime.
Which is cheaper, air source or ground source?
Air source is much cheaper to install, typically €12,000 to €18,000 before grants, because there is no groundwork. Ground source runs €20,000 to €30,000 due to the ground loops or borehole.
Which is more efficient?
Ground source is more efficient because ground temperature is stable year-round, so the system works less hard in winter. Air source efficiency dips in very cold weather but is more than adequate for the Irish climate.
Which should I choose for an Irish home?
Most Irish homes choose air source. It is far cheaper, quicker to install, and well suited to the mild Irish climate. Ground source makes sense on larger rural sites with the space and budget for groundwork.
Do both qualify for the SEAI grant?
Yes. Both air-to-water and ground source heat pumps qualify for the SEAI grant of up to €12,500 (as of July 2026), provided the installer is SEAI-registered. Every installer listed here is.
Is air source enough for a cold Irish winter?
Yes. Air source heat pumps are sized for Irish conditions and keep homes warm through a normal winter. Efficiency dips only in rare hard frosts, which the mild, damp Irish climate seldom reaches.
More on Heat Pumps and SEAI Grants
SEAI heat pump grant explained How the grant of up to €12,500 (as of July 2026) works and how to apply. Read guide 
Heat pump cost in Ireland What air source and ground source cost, before and after grants. Read guide 
Is my home suitable for a heat pump? Insulation, BER and radiators that decide suitability. Read guide 
Heat pump installers in Ireland SEAI-registered, grant-eligible installers in all 26 counties. Read guide Let an Installer Confirm the Right Heat Pump for Your Home
Air source vs ground source comes down to your site and budget. An SEAI-registered installer settles it in a free survey, and both qualify for the grant of up to €12,500 (as of July 2026).