Air purifier vs. dehumidifier: running cost
An air purifier is cheaper to run: about $63 a year versus $158 for a dehumidifier at typical use and 17.99¢/kWh, a $95 difference.
| Air purifier | Dehumidifier | |
|---|---|---|
| Typical watts | 40 W | 500 W |
| Watt range | 10–120 W | 250–750 W |
| Typical use | 24 hours a day | 24 hours a day for 6 months a year |
| Energy per year | 351 kWh | 877 kWh |
| Cost per hour | 0.7¢ | 3.6¢ |
| Cost per day | 17¢ | 86¢ |
| Cost per month | $5.26 | $26.28 |
| Cost per year | $63 | $158 |
| Per year in Hawaii (43.51¢) | $153 | $381 |
Compare at your rate and settings
What drives the difference
- Air purifier: Room air purifiers draw about 10-60 W and are usually run 24/7, so a non-ENERGY STAR unit can use 300-500 kWh a year.
- Dehumidifier: A 50-pint dehumidifier draws about 450-550 W while the compressor runs; the humidistat cycles it, so defaults give about 880 kWh over a humid season.
Ways to cut either cost
Delivers more clean air per watt.
See options on AmazonA DIY box-fan filter is a low-cost option for occasional smoke events.
See options on AmazonRemoves more moisture per kWh than older units.
See options on AmazonWe may earn a commission from qualifying purchases. It never changes the numbers we show. Disclosure.
Frequently asked questions
Which costs more to run, an air purifier or a dehumidifier?
At typical use and the U.S. average rate (17.99¢/kWh), a dehumidifier costs about $158 a year versus $63 for an air purifier. That's $95 more, or 2.5× as much.
How many watts do air purifier and dehumidifier use?
An air purifier typically draws 40 W (range 10–120 W). A dehumidifier draws 500 W (range 250–750 W). Watts alone don't decide cost. Hours of use, cycling and standby matter just as much.
Rates: EIA, 12 months ending 2026-07. Methodology.