Humidifier vs. warm mist humidifier: running cost
A humidifier is cheaper to run: about $9 a year versus $46 for a warm mist humidifier at typical use and 17.99¢/kWh, a $37 difference.
| Humidifier | Warm mist humidifier | |
|---|---|---|
| Typical watts | 30 W | 300 W |
| Watt range | 10–400 W | 150–450 W |
| Typical use | 10 hours a day for 5 months a year | 8 hours a day for 5 months a year |
| Energy per year | 48 kWh | 256 kWh |
| Cost per hour | 0.5¢ | 3.8¢ |
| Cost per day | 5.6¢ | 30¢ |
| Cost per month | $1.72 | $9.20 |
| Cost per year | $9 | $46 |
| Per year in Hawaii (43.51¢) | $21 | $111 |
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What drives the difference
- Humidifier: Ultrasonic humidifiers use 20-40 W and evaporative wick models 30-70 W. Warm mist and steam models boil water and use 200-400 W.
- Warm mist humidifier: Warm mist humidifiers boil water with a 150-450 W heater. The heat does slightly warm the room, but at heater cost.
Ways to cut either cost
Ultrasonic humidifier with humidistat
Uses about 30 W versus 300 W for warm mist models.
See options on Amazon Ultrasonic humidifier
Adds the same moisture at about 10% of the electricity.
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, a humidifier or a warm mist humidifier?
At typical use and the U.S. average rate (17.99¢/kWh), a warm mist humidifier costs about $46 a year versus $9 for a humidifier. That's $37 more, or 5.4× as much.
How many watts do humidifier and warm mist humidifier use?
A humidifier typically draws 30 W (range 10–400 W). A warm mist humidifier draws 300 W (range 150–450 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.