How Many Amps Does a Window Air Conditioner Use?

A window air conditioner uses about 10 running amps at 120 volts (roughly 1,200 watts). Because it is a motor load, it surges to several times that for a moment at startup. To get your unit's exact draw, divide the nameplate watts by 120: amps = watts / volts. A window air conditioner draws about 4-13 amps depending on size: a 5,000 BTU unit is roughly 4 to 6 amps (about 450-600 watts) depending on efficiency, a 12,000 BTU unit near 11-13 amps, plus a brief compressor surge. Small units share a 15A or 20A circuit; a large 120V unit wants a dedicated 20A circuit, and the biggest models are 240V. The unit's plug type tells you which.

A window air conditioner is typically put on a dedicated 20A / 120V circuit. A cord-and-plug room air conditioner may draw up to 80 percent of a circuit it has to itself (NEC 440.62(B)) and up to 50 percent of one that also supplies lights, other appliances or general-use receptacles (440.62(C)). At 10 amps this unit may be alone on a 15A or 20A circuit or share a 20A circuit; a dedicated 20A circuit is the common choice for a larger unit. At 10 running amps it is within 80 percent of that 20A circuit, 16A, the limit NEC 440.62(B) sets for a cord-and-plug room air conditioner on its own circuit.

Divide the wattage on the nameplate by the voltage: amps = watts / volts. A window air conditioner at about 1,200 watts on 120V works out to 1,200 / 120 = 10 amps. Add a startup surge of several times that for a fraction of a second on the motor. The nameplate always governs over a typical value.

Yes. A 5,000 BTU draws about 3.8 amps, while a 12,000 BTU draws about 11.7 amps. See the table above for the range. The rating on the nameplate is the number to size the circuit to.

Same answer: window ac is another name for a window air conditioner. It draws about 10 amps at 120V, typically on a dedicated 20A / 120V circuit. A window air conditioner draws about 4-13 amps depending on size: a 5,000 BTU unit is roughly 4 to 6 amps (about 450-600 watts) depending on efficiency, a 12,000 BTU unit near 11-13 amps, plus a brief compressor surge. Small units share a 15A or 20A circuit; a large 120V unit wants a dedicated 20A circuit, and the biggest models are 240V. The unit's plug type tells you which.