Ground source heat pumps in Ireland
A ground source heat pump costs €14,000–€18,000 fully installed in Ireland. It takes heat from pipes buried in the garden, is more efficient than an air source system, and qualifies for the same SEAI grant of up to €14,500.
How does a ground source heat pump work?
Pipes buried in the ground carry a fluid that picks up heat from the soil. A heat pump indoors raises that heat to a useful temperature and sends it to the radiators, underfloor heating and hot water cylinder.
It is also called a geothermal heat pump. There is no fan unit outside, so nothing is visible or audible in the garden once the ground is reinstated.
Ground source vs air to water
| Ground source | Air to water | |
|---|---|---|
| Installed cost | €14,000–€18,000 | €9,000–€14,000 |
| Efficiency (COP) | 4.0–5.0 | 3.0–4.0 |
| SEAI grant | Up to €14,500 | Up to €14,500 |
| Outside the house | Buried pipes, no outdoor unit | Fan unit beside the house |
| Best for | Rural homes with garden space | Most Irish homes, with radiators or underfloor heating |
Horizontal loops or boreholes
- Horizontal loops: pipes laid in trenches across the garden. Cheaper to install, but they need a large open area.
- Vertical boreholes: pipes dropped into drilled holes. They fit a small site, but drilling costs more.
Either way, the groundworks add €3,000–€6,000 to the price. That is the main reason ground source costs more than air to water.
Who a ground source heat pump suits
- Rural homes with garden space for the ground loops
- New builds, where the groundworks can be done with the site works
- Larger homes with a high heat demand, where the extra efficiency pays
- Homes where an outdoor fan unit is not wanted
For a typical home replacing a boiler, an air to water heat pump costs less and involves no digging. A ground source system lasts 15 to 20 years, the same as an air source one.