This is a genuinely confusing area, and not without reason — air conditioning and air source heat pumps use very similar underlying technology. Both move heat from one place to another rather than generating it directly. But they’re designed to solve different problems, and knowing which one you actually need matters before you start getting quotes.

The Core Similarity

Both systems work as heat pumps in the technical sense — they extract heat from outside air and move it indoors, or extract heat from indoor air and move it outside, depending on the mode. This is why the two get confused so often: mechanically, they’re close relatives.

Where They Differ

Air conditioning is primarily built around cooling and comfort — keeping a room at a comfortable temperature, most commonly in summer, though many systems also provide supplementary heating. It’s typically sized and installed room-by-room or zone-by-zone.

Air source heat pumps are a whole-house heating system, designed to replace your boiler as the primary source of heat and hot water for the entire property, connected to your existing (or upgraded) radiators or underfloor heating.

Some Systems Do Both

To add to the confusion: some air conditioning units are genuinely capable of both heating and cooling a room, which is why people sometimes describe a well-specified AC unit as “a bit like a heat pump.” It is, in a narrow technical sense — but it’s not doing the job of a whole-house heat pump replacing your boiler.

Which One Do You Actually Need?

Want a specific room (home office, bedroom, conservatory) to be comfortable in summer, and maybe get a heating boost in winter too? That’s air conditioning.
Want to replace your boiler as your whole-house heating and hot water system? That’s an air source heat pump — a bigger, whole-property decision, not a room-by-room one.

Why This Matters for Your Quote

Because these solve different problems, they’re priced, sized, and installed completely differently. If you go into a conversation not sure which one you actually need, that’s completely normal — it’s exactly what a proper survey is for.

See our Wind (Air Conditioning) hub for room-by-room cooling and heating, or our Air Source Heat Pumps page under Fire for whole-house heating replacement.