What does it cost to run air conditioning at home in the UK?
It's the question everyone asks before buying: "won't it cost a fortune to run?" The honest answer for 2026 — used sensibly, far less than people fear, and the type of system makes a big difference.
Cooling costs come down to how much electricity a system draws and how long you run it. Here's how the common options stack up at current UK electricity prices. Treat these as typical ranges — your actual cost depends on your tariff, your home and the weather.
Portable air conditioners
The cheapest to buy, the priciest to run for the comfort you get. Industry guides put them at roughly 21–37p per hour — around £50–£88 a month if run about eight hours a day through a hot spell. They're noisy, only cool one room, and need a hose out of a window.
Fixed split air conditioning
A wall-mounted "split" is far more efficient than a portable. In cooling mode a single-room split typically runs at around 10–30p per hour. Much better — but it's still one unit cooling one room, with an outdoor condenser and a visible indoor head.
Heat-pump cooling (the efficient route)
Here's the bit worth knowing: modern systems run as heat pumps, and in cooling mode a good one achieves a "SEER" of 4–6 — meaning it moves four to six units of heat for every unit of electricity. In practice that can cool your home for roughly 30% less electricity than an older dedicated AC unit, with cooling costs often in the region of £60–£80 across a hot month rather than £90–£110.
Don't forget installation and servicing
- Portable: nothing to install, but poor value over time.
- Single split: typically £2,000–£3,500 installed for one room.
- Whole-home system: a bigger upfront investment, but it replaces several systems and adds heating and ventilation. Try our 60-second estimator for an indicative figure.
- Servicing: budget roughly £70–£120 per unit a year to keep things efficient and under warranty.
Five ways to keep running costs down
- Set a sensible target (24–25°C is comfortable and far cheaper than 19°C).
- Use it in the rooms you're actually in, and zone where possible.
- Keep blinds closed on south-facing windows during the day.
- Service it annually so it runs at peak efficiency.
- Choose an efficient, correctly-sized system from the start — oversized kit wastes money.
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How much does it cost to run AC per hour in the UK?
Roughly 21–37p per hour for a portable, around 10–30p per hour for an efficient single split in cooling mode, and less again per unit of cooling for a well-designed heat-pump system.
Is it cheaper to cool with a heat pump?
Generally yes. A heat pump in cooling mode is highly efficient and can use around 30% less electricity than an older dedicated AC unit — and the same system heats your home too.
Does air conditioning use a lot of electricity?
Only if you run it hard, all day, at a very low temperature. Sensibly used and correctly sized, the cost is modest for the comfort and sleep it buys you.