Air-source and ground-source heat pumps both heat your home using renewable energy. We compare costs, efficiency, installation, and noise to help you choose.
Quick Comparison
| Factor | Air Source | Ground Source |
|---|---|---|
| Cost | £8,000-£14,000 | £15,000-£35,000 |
| Efficiency (COP) | 2.5-3.5 | 3.5-4.5 |
| Space | Garden space for unit | Large garden or borehole |
| Noise | 35-45 dB (fan) | 10-20 dB (silent) |
| Installation Time | 3-5 days | 1-2 weeks |
| Planning Permission | Usually not needed | Sometimes required |
| Payback Period | 10-15 years | 15-20 years |
Air-Source Heat Pumps
How They Work: Extract heat from outdoor air (works even at -10°C) and compress it for heating. Works like a refrigerator in reverse.
Advantages: Lower cost, faster installation (3-5 days), no garden excavation, easier retrofitting
Disadvantages: Lower efficiency (COP 2.5-3.5), fan noise (35-45 dB), requires outdoor unit space
Best For: Most UK homes, limited budgets, apartments with outdoor space
Ground-Source Heat Pumps
How They Work: Extract heat from ground (constant 10-12°C) via pipes buried 1.5m deep. More stable temperature source.
Advantages: Higher efficiency (COP 3.5-4.5), nearly silent, lower running costs
Disadvantages: High upfront cost (£20,000-£35,000), requires large garden, long installation, disruptive groundworks
Best For: Homes with large gardens, long-term owners, high heating demands
Running Costs Comparison
Air Source COP 3: Effective cost 24.5p / 3 = 8.2p per kWh of heat
Ground Source COP 4: Effective cost 24.5p / 4 = 6.1p per kWh of heat
Ground source typically saves 20-30% annually on running costs despite higher installation.
Installation Disruption
Air Source: 3-5 days. Requires 1-2 square metres of outdoor unit space. Minor electrical work.
Ground Source: 1-2 weeks. Requires garden excavation (trenches or borehole). Major disruption. Excellent for new builds.
Which Should You Choose?
- Choose Air Source If: Limited budget, smaller garden, faster payback important, noise acceptable
- Choose Ground Source If: Large garden, long-term resident (15+ years), maximum efficiency needed, noise sensitivity
Get Quotes for Both Types
Compare air and ground source quotes from MCS-certified installers in your area.