How many watts does a portable AC use?
Updated
Running watts
900 W
Starting watts
2,700 W
Energy per day
7.2 kWh
A portable AC typically draws about 900 watts while running and up to 2,700 watts for a second or two when the motor starts. At about 8 h of use a day, that is roughly 7.2 kWh per day. These are typical values from generator wattage charts: the label on your own appliance (or its EnergyGuide sticker) gives the exact figure.
What size generator do I need for a portable AC?
Plan for at least 3,240 W: 2,700 W to get through the start-up surge, plus a 20% margin so the generator never runs flat out. Of the common sizes, a 3,500 W generator is the smallest that fits.
| Generator | Can it run a portable AC? |
|---|---|
| 2,000 W | No |
| 3,500 W | Yes |
| 5,000 W | Yes |
| 7,500 W | Yes |
| 10,000 W | Yes |
| 15,000 W | Yes |
How long will a power station run a portable AC?
Running continuously at 900 W, assuming 85% of the battery is usable. The station's AC output must also handle the 2,700 W start-up surge.
| Battery capacity | Runtime |
|---|---|
| 1,000 Wh | about 57 min |
| 2,000 Wh | about 2 h |
| 3,600 Wh | about 3 h |
Running more than one appliance?
Starting surges don't add up the way running watts do. Pick everything you want to power to get your real number.
Open the Generator Size Calculator for Your HomeFrequently asked questions
What size generator do I need to run a portable AC?
At least 3,240 W: 2,700 W to cover the start-up surge, plus a 20% safety margin.
Can a 2,000 watt generator run a portable AC?
No. It needs about 2,700 W for a second or two when it starts, more than 2,000 W.
Can a 3,500 watt generator run a portable AC?
Yes. 3,500 W covers its 2,700 W starting surge with room to spare.
How long will a 1,000 Wh power station run a portable AC?
About 57 min, assuming 85% usable capacity, as long as the station's AC output is rated for 2,700 W of surge.
Never run a generator indoors or in a garage: see the CPSC safety guide.