United Kingdom Cooling and fans
How much does it cost to run a portable air conditioner?
A portable air conditioner draws about 1,000 to 1,500 watts and is the least efficient way to cool a room, because the hot side of the machine sits inside the room with you and most of them pull cooled air out through the exhaust hose.
A 1.2 kW portable air conditioner costs about 24p an hour to run in Great Britain at 26.32 pence per kWh. Running it 8 hours a day cycling 75% of the time comes to about £1.90 a day, £57.68 a month and £692.16 a year.
- Price: Ofgem cap, Oct to Dec 2026
- Wattage range with its source
- Checked 26 October 2026
Uses 7.2 kWh a day, 219 kWh a month, at 26.32 pence per kWh (Great Britain (price cap average)).
The dial places the daily cost between a 50 watt fan and a 4.5 kW water heater on 2.5 hours a day.
A 1.2 kW portable air conditioner costs about 24p an hour to run in Great Britain at 26.32 pence per kWh. Running it 8 hours a day cycling 75% of the time comes to about £1.90 a day, £57.68 a month and £692.16 a year.
What this assumes
The default is a 1.2 kW portable air conditioner running 8 hours a day, drawing full power 75% of the time it is switched on (the rest of the time a thermostat or sensor has it idle). Published typical ratings run from 900 to 1,500 watts. Your label or manual gives the exact figure, and the calculator takes it.
The price is the Ofgem price cap unit rate for 1 October to 31 December 2026, average for England, Scotland and Wales, paying by Direct Debit. The cap for 1 January to 31 March 2027 is announced in late November 2026. A fixed tariff, a time-of-use plan or a different payment method changes the rate, which is why the rate field is editable.
Cost by wattage and hours at the price cap rate
At 26.32p per kWh, running flat out. Multiply by the share of the time your thermostat keeps the element on.
| Power | 1 hour | 8 hours | 24 hours | A week at 8 hours a day |
|---|---|---|---|---|
| 900 watt | 24p | £1.90 | £5.69 | £13.27 |
| 1.2 kW | 32p | £2.53 | £7.58 | £17.69 |
| 1.5 kW | 39p | £3.16 | £9.48 | £22.11 |
How a portable air conditioner uses electricity
Single-hose units draw warm air into the room from elsewhere in the house to replace what they blow out of the window. Dual-hose units avoid that and cool the same room on noticeably less run time.
Because the cooling is less effective, the compressor runs more of the time than a window unit would, so the duty assumed here is 75%.
Ways to cut the cost
- Seal the window kit properly. A gap undoes most of the cooling.
- Keep the hose short and straight.
- Pre-cool the room in the evening rather than fighting the afternoon sun.
Questions people ask
Why is my portable AC so expensive to run?
Three reasons: it draws 1,000 to 1,500 watts, it rejects heat inside the room, and the exhaust pulls warm air in from the rest of the house. It runs longer to do the same job as a window unit.
How much does a portable AC cost per hour?
At 1,200 watts and 75% duty, about 0.9 kWh an hour. At 18 cents that is about 16 cents an hour, at 26p about 24p an hour.
Other cooling and fans costs
More in the UK
Sources
The electricity price on this page is read from the data file that also lists the release it came from. The wattage range is a published typical range, not a measurement of your appliance.