Portable air conditioners ranked by cost to run
Free-standing units you wheel between rooms and vent out of a window. We rank every portable air conditioner by what it actually costs to run per hour, not just its price tag.
Are portable air conditioners worth it? →- Typical efficiency
- EER ~8.5
- Power (12k BTU)
- ~1,400 W
- Cost/hr (UK)
- ~£0.35
- Install
- None — DIY
- Noise
- 50–65 dB
Typical figures for a 12,000 BTU unit at UK rates (£0.245/kWh) — see the live listings below for exact specs per model.
Guides for portable air conditioners
Portable air conditioners: frequently asked questions
How much does a portable air conditioner cost to run?
A typical 9,000–12,000 BTU portable draws around 1,000–1,400 W. At the UK average of £0.245/kWh that is roughly £0.25–£0.34 per hour; in the US at $0.16/kWh, about $0.16–$0.22 per hour. Portables are the least efficient AC type (EER ≈ 8.5), so they cost more per hour of cooling than a comparable split or mini-split.
Are portable air conditioners less efficient than split units?
Yes. Portables average an EER around 8.5 versus roughly 11–12 for split and mini-split systems, and single-hose models lose extra efficiency to negative-pressure infiltration. For the same BTU you typically pay 20–40% more per hour to run a portable.
What size (BTU) portable do I need?
Start from roughly 450 BTU per m² (about 20 BTU per sq ft), then add capacity for sunny rooms, high ceilings, kitchens and extra people. Use our BTU calculator to get a figure, then sort the table by cost per hour.
Do portable air conditioners need a window?
Almost always — the exhaust hose has to vent hot air outside, usually through a window kit or a wall vent. "Ventless" evaporative coolers are a different product and do not refrigerate the air.
