Cost to run a portable air conditioner per hour

So an evening of cooling, say five hours, adds roughly £1 to £2 to the bill, and a hot week of daily use adds more than a tenner. The figures below break that down by model, by night and by month, and show how to cost your own unit.

What a typical portable unit costs per hour

The headline range of 20p to 40p an hour comes from three independent and maker figures that agree closely. National Energy Action gives 26p to 39p an hour for a typical 1,000 to 1,500W portable unit, and notes that is roughly 14 to 20 times the cost of running a fan¹. Uswitch's guide, calculated at the July 2026 price cap rate of 26.11p per kWh, gives 20p to 39p an hour for portable units of 0.75 to 1.5kW². The retailer electriQ quotes 25p to 40p an hour in cooling mode for its EcoPlus10HPW, based on standard UK prices of 25p to 35p per kWh³.

The spread within that range is driven by two things: the unit's power rating and your electricity tariff. Portable units typically draw between 900 and 2,000W, and the higher the BTU rating the higher the power draw tends to be⁶. Your own unit rate may sit above or below the cap rate used in these calculations, so treat the range as a guide and cost your own unit using the formula further down this page.

Real running costs quoted for specific models

Makers publish running costs for their own portable units, and the quoted figures run from 25p to 40p an hour across the range. Meaco's figures are worked examples: its MeacoCool MC Series Pro is quoted at 25p an hour, based on a 24.67p per kWh rate, its Cirro at 35p an hour, and its Cirro+ at 40p an hour⁷.

These are maker-quoted figures at the rates each maker states, so they are not directly comparable with each other or with the price cap calculations above. What they do show is the shape of the market: a smaller unit costs around 25p an hour and the largest portables around 40p, which matches the independent range closely.

Cost per night and per month

Uswitch's analysis of summer 2026 cooling costs looked at the 2.2 million homes with portable units, which use 1kW of power, running them for an average of 9.1 hours a day⁴. On the cheapest fixed rates then available, that worked out at £1.47 a day and £13.37 a week; on predicted July rates it was £1.84 a day and £16.70 a week⁴.

Scaled to a month of hot weather, a household using its unit most days through a four-week warm spell would add somewhere in the region of £50 to £67, using those weekly figures. That assumes daily use, which most UK homes will not see: portable units tend to come out for heatwaves rather than all summer.

For context, that weekly figure sits between other summer appliances: a dehumidifier costs around 5p to 15p an hour to run, and a heated clothes airer about 8p an hour at the July 2026 cap rate, so a portable air conditioner is one of the more expensive plug-in appliances in the house².

Cooling versus heating mode

Many portable units are reversible, so they can heat a room in winter as well as cool it in summer. The hourly cost is similar in both modes: electriQ estimates its EcoPlus10HPW at 25p to 40p an hour in cooling mode and 20p to 40p an hour in heating mode³.

What differs sharply is the heat you get for that money. A reversible air conditioner in heating mode produces 2 to 3 kWh of heat for every kilowatt-hour of electricity it consumes, because it moves existing heat rather than generating it directly³. A plain electric heater gives out no more than 1 kWh of heat per kWh of electricity, which is why fan heaters cost around 60p an hour and convector heaters around 48p an hour on average¹⁰. In winter, a reversible portable is therefore a much cheaper way to heat one room than a plug-in heater of the same wattage.

Do bigger BTU models cost more per hour?

Usually, but not always in practice. Portable air conditioners typically range from 900 to 2,000W, and the higher the BTU rating the higher the power draw⁶, so a larger unit costs more per hour than a smaller one when both are running flat out, as the maker figures above show⁷.

The catch is that the running cost is determined by the duty cycle, how long the unit actually needs to draw power each hour to hold the set temperature, rather than by its wattage rating alone¹¹. An oversized unit in a small room will cycle off once the room is cool and may cost less over an evening than a small unit running continuously in a room it cannot cope with. Sizing the unit to the room, rather than buying the biggest available, is what keeps the real cost down; our guide to air conditioning sizing covers this.

How to work out the cost for your own unit

The standard formula is:

So a 1,000W unit on a 27p per kWh tariff costs 27p an hour at full power, and a 1,500W unit on the same tariff costs about 41p. Which? gives a worked example of a 2kW fan heater costing 55p an hour at 27.69p per kWh¹³. The wattage is printed on the appliance label or in the manual, and your unit rate is on any recent bill.

Two refinements make the figure more honest. First, use your own tariff rate, not the cap rate, since the results differ noticeably. Second, remember the duty cycle: the formula gives the cost of running flat out for a whole hour, and a unit that reaches temperature and switches off will cost less¹¹. The Consumer Council for Northern Ireland offers an appliance checker that works out costs on a per-minute, per-hour and per-day basis¹⁴.

How the cost compares with a fan

A fan is far cheaper to run. The average fan costs around 3p an hour, according to the Centre for Sustainable Energy⁵, and Ecotricity notes that a standard fan costs 20 times less to run than a portable air conditioner¹⁵. National Energy Action's estimate of 14 to 20 times more for a portable unit sits in the same territory¹.

The reason is physics rather than quality: a fan only moves air, while a portable unit has a compressor doing real work. Portables are also inherently less efficient than fixed systems, using 30 to 50% more electricity for the same cooling, because the whole machine sits inside the room and its exhaust hose arrangement leaks cooled air⁵. Our comparison of air conditioning versus fans covers when each is worth it.

Purchase price versus running cost

Portable packaged air conditioners cost between £170 and £700 depending on capacity and features¹⁶. Netatmo's guidance gives a wider market range, from around £250 for entry-level models to more than £3,500 for sophisticated systems such as portable split air conditioning¹⁷.

Set against that purchase price, the running cost is the bigger commitment over a hot summer. A unit bought for £250 and run for four hot weeks at the weekly costs above would add £53 to £67 in electricity in its first year alone⁴. Fixed air conditioning costs more to install, with installation prices of £500 to £720 a day quoted via Checkatrade¹⁸, but its lower electricity use per hour of cooling⁵ narrows the gap over time. For the independence angle, a portable unit is entirely dependent on grid electricity at your supplier's rate: there is no way around that, though running one from your own solar generation is covered in cooling with solar panels.