When you're trying to stay cool without a scary electricity bill, the fan is your friend. It's the most economical cooling device you can buy and run. Here's why, and how to think about its cost over a whole summer.
Why fans are so cheap to run
A fan does only one thing electrically: spin a small motor to move air. It doesn't run a compressor or refrigerate anything, so it draws a tiny fraction of the power an air conditioner uses. That's the whole reason a fan is the cheapest cooling device — low power in, all summer long. Even left running for hours, a fan adds only a small amount to your bill.
Running it all summer
Because the draw is so low, you can comfortably run a fan through hot days and evenings without watching the meter. Leaving a fan on while you're in the room is one of the most cost-effective comfort decisions you can make. The one habit worth keeping: turn it off when you leave the room, since a fan only cools people, not empty space — that's about avoiding waste, not a big cost.
How it compares to coolers and AC
On running cost, the three devices line up clearly:
| Device | Relative running cost |
|---|---|
| Fan | Lowest by far |
| Evaporative air cooler | A modest step up |
| Mobile air conditioner | Much higher |
A fan costs a small fraction of what an air conditioner does to run, with an air cooler sitting in between. See the full picture in our cost-of-cooling guide.
The smart, economical strategy
Use the cheapest device that does the job for the day. On milder warm days, a fan alone keeps you comfortable for almost nothing. Reserve the pricier air cooler or mobile AC for the genuinely hot, sticky nights when only more cooling will do. Layering a fan with free tactics — shading, night ventilation — stretches its effectiveness further still.
The bottom line
A fan is cheap to buy and cheap to run, which makes it the foundation of an economical summer-cooling setup. Run it freely while you're in the room, turn it off when you leave, and lean on it for all but the hottest days. Check which fans are in stock near you and start cooling for pennies.