The Two Main Types of Heat Pump
When considering a heat pump for your UK home, you'll encounter two main technologies: air source heat pumps (ASHP) and ground source heat pumps (GSHP). Both use the same refrigeration cycle to extract and deliver heat, but they draw energy from different sources.
Air Source Heat Pumps
ASHPs extract heat from ambient outdoor air using a fan-driven unit installed outside your property. They are by far the most popular choice for UK residential properties, accounting for the vast majority of heat pump installations under the Boiler Upgrade Scheme.
- Installation cost: £8,000–£15,000 (after BUS grant)
- Typical CoP: 2.8–4.2
- Space required: External wall or ground space for outdoor unit
- Installation time: 1–2 days
- Suitable for: Most UK properties
Ground Source Heat Pumps
GSHPs extract heat from the ground via buried collector loops or boreholes. Ground temperatures in the UK remain relatively stable at 10–12°C year-round, giving GSHPs a more consistent and slightly higher CoP than ASHPs.
- Installation cost: £15,000–£30,000
- Typical CoP: 3.5–5.0
- Space required: Large garden for horizontal collectors, or borehole drilling
- Installation time: 3–5 days (horizontal) or 1–2 weeks (borehole)
- Suitable for: Rural properties with land available
Running Costs Compared
Thanks to their higher CoP, GSHPs tend to have slightly lower running costs. However, the higher capital cost means the payback period is longer. For most homeowners, an ASHP offers the better overall financial case, especially with the £7,500 Boiler Upgrade Scheme grant available.
Which Should You Choose?
Choose an ASHP if you have a typical suburban property with limited outdoor land, want a lower upfront cost, or live in an area with a moderate climate. Choose a GSHP if you have rural land available, want the highest possible efficiency, or your outdoor space makes an ASHP impractical. In both cases, ensure your home is well-insulated before installation to get the most from your investment.
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