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How Much Does It Cost to Run a Evaporative (Swamp) Cooler? (2026)
An evaporative cooler is only a fan and a small pump, so it uses a quarter or less of the electricity of an air conditioner of similar cooling capacity. It only works well in dry climates.
A typical evaporative (swamp) cooler (300 W) costs $0.054 per hour, or about $12.96 per month at 8 hours a day in United States (average). Average running cost
| Wattage | Per hour | Per day | Per month | Per year |
|---|---|---|---|---|
| Low (100 W) | $0.018 | $0.14 | $4.32 | $52.56 |
| Typical (300 W) | $0.054 | $0.43 | $12.96 | $157.68 |
| High (800 W) | $0.14 | $1.15 | $34.56 | $420.48 |
Formula: watts ÷ 1000 × hours × price per kWh. Typical use is 8 h/day ≈ 876 kWh per year.
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How to lower the cost of running a evaporative (swamp) cooler
- Open a window on the far side of the room. Swamp coolers need airflow out to work.
- Replace pads each season. Clogged pads cut cooling and make the fan work harder.
- Run the pump a few minutes before the fan so pads are wet from the start.
Frequently asked questions
Is a swamp cooler cheaper to run than AC?
Yes, typically 3 to 5 times cheaper per hour, but it cannot cool a humid room.
How much water does an evaporative cooler use?
Around 10 to 25 litres per hour for a whole-house unit, less for portable ones.
Can I run a swamp cooler all day?
Yes. At 300 watts, 24 hours uses 7.2 kWh, about the same as an AC running two to three hours.
Cost by region
- United States (average)
- California
- Texas
- New York
- Florida
- Canada (average)
- United Kingdom
- Germany
- France
- Australia
- India