A window AC pulls approximately 5-12 Amps, with some models using more amps. Here is the breakdown based on the capacity of a window AC:

• Small window AC units (5,000 to 8,000 BTU) typically use 5 to 7 amps.
• Medium window AC units (10,000 to 12,000 BTU) often use between 8 to 12 amps.
• Large window AC units (14,000 to 25,000 BTU) can use anywhere from 12 to 20 amps or more.

The specific amperage can usually be found in the AC unit's manual or on a label attached to the device. It's important to check this before installation to ensure your electrical system can handle the load, especially if you plan to plug it into a standard 120-volt outlet. Larger units require a dedicated circuit to avoid overloading your electrical system.

Window AC Defined

A window AC is a standalone air conditioner unit installed through the window. Unlike traditional air conditioner units, window ACs are designed to be self-contained, meaning all components are housed within one unit. Installation is relatively straightforward and can be done by the homeowner in most cases. Window units are cheap and cost-effective for cooling single rooms or small spaces. They are often used by renters who want to avoid investing in more advanced HVAC units in smaller apartments. They are also used when the ductwork is impractical.

Can I run a window AC on a 15 amp circuit?

You can run a window AC on a 15 amp circuit as long as it is the only major appliance on that circuit, or the circuit is dedicated. Window AC units from 5,000 to 12,000 BTU draw only 5 to 12 amps, which tracks for a 15 amp circuit. You'd better get a dedicated circuit for larger window units, particularly those near or above 12,000 BTUs.

Does a window AC need a 20 amp outlet?

Most window ACs don't need a 20 mp outlet unless they are very large (14,000 to 25,000 BTU) and draw more than 15 Amps. 

Cables For Window AC

NM-B wire is the most common type of cable for window AC units. Unless there is a conduit installation required by local codes, NM-B wire is the obvious choice. Here is the breakdown:

• For the smallest units drawing 5-10 amps, go for 14/2 NM-B cable.
• For units drawing up to 15 amps, 12/2 NM-B is the best choice of cable. Both of these require a 120-volt supply.
• For a 240-volt supply, the common choice of cables is 10/2 or 12/2, depending on the exact amp draw.

NM-B wire in required sizes is available at NNC, with reduced prices for 250’, 500’, and 1000’ runs.