Ceiling Fan vs Air Conditioner Cost: Which is Cheaper?

The fan costs a fraction of the air conditioner

A ceiling fan typically draws 50 to 100 watts on its highest setting. A window air conditioner uses 500 to 1,500 watts, and a central system can pull 2,000 to 5,000 watts. At the same electric rate, a fan costs roughly 5 to 10 percent of what the air conditioner costs per hour.

The reason is physics: moving air requires much less energy than removing heat and humidity from it. A fan does not cool the room, it creates a wind-chill effect on your skin that makes you feel cooler.

When a fan alone is not enough

Once the indoor temperature and humidity rise above comfort, a fan cannot lower the actual air temperature. Running a fan in an empty room wastes energy because the wind-chill effect only works on people. On very hot and humid days the air conditioner has to run anyway, and the fan becomes a supplemental tool.

• Use the fan only in occupied rooms for the wind-chill benefit.
• Turn the fan off when leaving the room; it cools people, not spaces.
• A dehumidifier can reduce the moisture load, letting you raise the thermostat slightly while maintaining comfort.

The hybrid strategy saves the most

Set the air conditioner to a higher temperature, such as 78°F instead of 72°F, and run ceiling fans in occupied rooms. The fan makes the warmer air feel cooler, and every degree you raise the thermostat reduces air-conditioning energy use by about 3 to 5 percent.

The total electricity cost can drop significantly because the fan's low wattage offsets only a small fraction of what the air conditioner saves by cycling less.