How much does a portable air conditioner cost to run?

Running cost depends on three things: the unit's power draw (kW), how long it runs, and your electricity price. At the 2026 UK average of around 24.5p per kWh, a 1 kW portable AC running flat out costs roughly 25p an hour. In practice the compressor cycles on and off once the room reaches temperature, so real cost is usually 50–80% of that — which is why this calculator includes a compressor running-time setting.

How to lower your running costs

Pick a higher energy rating (A++ models like the PAC EX100 Silent draw less power for the same cooling), use eco or "real feel" modes, seal the window kit well so cool air isn't wasted, set a sensible target temperature, and use a timer overnight.

Frequently asked questions

Is a portable air conditioner expensive to run?

For typical evening use (a few hours a day) most portable ACs cost between £0.10 and £0.30 per hour at UK electricity prices — use the calculator above for your exact figure.

Which is cheaper to run, a higher or lower BTU unit?

A more efficient, higher-rated unit (A+/A++) can cool a room faster and cycle off sooner, often costing less overall than a cheap, low-rated model — even if its peak power is higher.

Does a portable AC use more electricity than a fan?

Yes — a fan uses far less power, but it only moves air rather than cooling it. An air conditioner actively lowers the temperature, which is why it costs more to run.