Air conditioning vs heat pump: what's the difference?
Here’s the part that trips most people up: if you’re comparing “air conditioning” against “a heat pump” as though they’re two different products, they’re very often the same thing wearing two different names.
Same machine, different job description
Nearly every wall-mounted or multi-split system sold in the UK today is a reversible heat pump: it moves heat out of a room to cool it in summer, and moves heat into a room to warm it in winter, using the same refrigerant cycle in both directions. Call it “air conditioning” and people picture cooling. Call it “a heat pump” and people picture central heating. Functionally, for this type of system, they’re the same unit.
Where the real distinction sits
The genuine split in the market is between:
- Air-to-air systems: what we install. They heat and cool the air directly in the room, room by room, with no connection to your boiler, radiators, or hot water cylinder.
- Air-to-water systems: a different product entirely, which replaces your boiler and heats water that then runs through your existing radiators or underfloor heating and hot water cylinder, the same way a gas boiler does today.
Both are, technically, heat pumps. Only air-to-water systems currently qualify for the government’s Boiler Upgrade Scheme grant. See our separate guide on that if a grant is part of your decision.
Which one you actually want
If you want to cool specific rooms in summer (a bedroom that gets unbearable in July, a home office, a loft conversion) and heating those same rooms more efficiently in winter is a welcome bonus rather than the main goal, an air-to-air system is the right product, and it’s what we install.
If you’re trying to replace your entire gas boiler and central heating system, that’s an air-to-water heat pump project: a larger undertaking with different installers, different costs, and different grant eligibility, and not something covered by a wall-mounted air conditioning quote.
The one thing both share
Whichever you choose, look for the same signals of quality: an MCS or F-Gas certified installer, a clear efficiency rating, and a fixed price that’s explained rather than just quoted.