An 8000 BTU window air conditioner typically needs about 700 watts to run. Most homes in the United States have access to 120-volt power outlets, so you'll need a unit that can operate on that voltage. Many models also come with an adapter to allow them to work with 220-volt outlets, which are more common in other parts of the world. The current draw for an 8000 BTU window air conditioner will be about 6.3 amps on a 120-volt circuit, or 3.2 amps on a 220-volt circuit.