If you’ve ever considered getting a portable air conditioner, you’ve probably heard the age-old response of  “They’re expensive to run.”

But in 2025, with UK households facing more frequent heatwaves, it’s worth looking at the real numbers, and you might be pleasantly surprised at how affordable cool, comfortable air can be.

At Chilly Pepper Hire, we provide portable air conditioner hire for homes and businesses across London, so we know exactly how much they cost to run. In this article, we’re going to run through how it’s probably less than you think.

UK Electricity Prices in 2025

From 1 July to 30 September 2025, Ofgem’s energy price cap sets the default electricity rate at 25.73 p/kWh, with a daily standing charge of 51.37 p (based on direct debit averages across Great Britain). This represents a 7% drop from the previous quarter, bringing the typical annual bill down to around £1,720 (MoneyWeek).

That’s good news, and it means cooling your home won’t sting as much as it might have last summer.

Running Costs of a Portable Air Conditioner

Most modern portable air conditioners are energy efficient:

• Small units (0.9–1.2 kW) → around £0.26/hour to run.
• Mid-size units (~1.3–1.6 kW) → around £0.33–£0.41/hour.

So, if you ran a 1 kW portable AC for 8 hours a day, you’d spend roughly:

• £2.10/day
• Around £60/month for a full hot month

Even a larger mid-size unit would only cost £2.70–£3.30/day, or £80–£100/month, depending on usage.

Putting It in Perspective

Here’s how that compares with other common appliances:

• Fridge/freezer: £7.50–£15/month
• Kettle: ~£0.05 per 3-minute boil — several cups of tea a day soon add up.

Fans are cheaper to run, but they only move air around; they don’t actively lower the temperature. Portable AC units remove heat, making them especially valuable for better sleep, productivity, and comfort during heatwaves.

Tips to Keep Costs Low

• Pick the right size: Use our BTU calculator to get a unit that matches your room size.
• Use timers so it’s only on when you need it. The £60/month figure above is based on running the AC unit for 8 hours a day, every day of the month. In reality, you probably wouldn’t need the unit running for this amount of time.
• Block direct sunlight with blinds or curtains during the day.
• Keep doors and windows shut while cooling to avoid wasting energy.

The Bottom Line

Yes, portable air conditioners do cost more than some other appliances, but chances are, it’s probably not as much as you might think. In the UK’s recent hot spells, the comfort is well worth the modest cost.

For under £3 a day, you can keep your home cool, sleep better, and beat the heat during the one or two months that we have it!

If you’re ready to stay comfortable this summer without breaking the bank, check out our air con hire costs page for more details on renting a unit from us.