How Much Does It Cost to Run an Air Conditioner?

Cooling capacity is not electrical input

BTU/h describes cooling output. The power consumed is usually listed in watts or amps and volts on the label or specification sheet.

Using cooling capacity as if it were electric power can produce a very inaccurate cost estimate.

Account for cycling and variable speed

A fixed-speed compressor cycles off after reaching the thermostat setting. Inverter systems modulate output rather than staying at maximum draw.

If no measured average is available, calculate a range using several load factors instead of presenting one precise number.

• Low case: 40–50% average load
• Middle case: 60–70%
• High case: 80–100% during extreme heat

The cheapest kWh is not the only factor

Insulation, solar gain, thermostat setting, filter condition and room sealing influence runtime. Time-of-use tariffs can also make the hour of operation important.

Compare scenarios using the same comfort assumption; otherwise a cheaper result may simply reflect less cooling.