Calculator
Swamp Cooler vs Air Conditioner Running Cost Calculator
Compare the monthly cost of running an evaporative cooler against central air conditioning, including the cooler's water, using your own electricity rate.
The running cost gap between evaporative cooling and refrigerated air is the main reason people in dry climates choose a swamp cooler. Enter your own numbers to see the difference for your home. Defaults are typical examples, not your utility's rates.
How the calculation works
Cost = kW × Hours × Days × Rate
SEER2 is a seasonal average, so this gives a fair estimate of average draw across a cooling season. On the very hottest afternoons an air conditioner's efficiency falls and its draw rises, which tends to widen the gap. The swamp cooler cost adds water at your price per 1,000 gallons.
Worked example: default values
A 3 ton, 14 SEER2 air conditioner averages 3 × 12,000 ÷ 14 ÷ 1,000 = 2.57 kW. Over 300 hours at $0.15 that is about $116. A swamp cooler at 0.6 kW costs 0.6 × 300 × 0.15 = $27 in electricity, plus 3,000 gallons of water at $6 per 1,000 = $18. Total $45, a saving of about $71 for the month, or about 61%.
What the calculator does not capture
- Comfort is not identical. In a marginal climate, an air conditioner will hold a lower, drier indoor temperature. Check your conditions with the cooling temperature calculator.
- Maintenance costs. Coolers need pads, occasional pumps and belts, and seasonal service. See the maintenance schedule.
- Time-of-use rates. If your utility charges more in late afternoon, the savings are larger, because that is exactly when the AC works hardest.
For a deeper breakdown, read swamp cooler operating cost and swamp cooler vs air conditioner.
Frequently asked questions
How much does it cost to run a swamp cooler per month?
A whole-house cooler drawing about 0.6 kW for 10 hours a day uses about 180 kWh a month, roughly $27 at $0.15 per kWh, plus a few dollars of water. Larger units on high speed cost more.
How much cheaper is a swamp cooler than AC?
In dry climates, running costs are commonly 60 to 80% lower than central air conditioning for the same hours, because a blower and pump draw far less power than a compressor.
Does the comparison include installation cost?
No. This calculator compares running costs only. For purchase and installation costs see our guides to what a swamp cooler costs and what installation costs.
What SEER2 value should I use?
Use the rating on your AC's label if you know it. New central systems in the U.S. are commonly 13.4 to 16 SEER2 or higher; older systems can be much lower, which makes the savings bigger.