A humidifier uses less electricity than most appliances in your home

A typical humidifier draws between 300 and 700 watts while running, which is less than a hair dryer, space heater, or window air conditioner. Running one for eight hours a day costs roughly $1 to $3 per month in electricity, depending on your local rates and the model's wattage. The smallest ultrasonic humidifiers use around 20 to 30 watts; larger evaporative or steam models can reach 1,000 watts, but even at that level, the monthly cost stays under $10 for typical household use.

The actual cost depends on three things: the humidifier's wattage (listed on the device or manual), how many hours per day you run it, and your local electricity rate. You can find your rate on your electric bill — it is usually shown as cents per kilowatt-hour (kWh). A straightforward way to estimate: multiply the wattage by the hours you run it daily, divide by 1,000, multiply by your rate, then multiply by 30 for a monthly estimate.

Key Takeaways

  • Most humidifiers use 300 to 700 watts and cost $1 to $3 per month to run eight hours daily.
  • Ultrasonic humidifiers are the most efficient, using as little as 20 to 30 watts.
  • Steam humidifiers use the most power, sometimes reaching 1,000 watts, but are still cheaper to run than a space heater.
  • Your actual cost depends on the model's wattage, how long you run it each day, and your local electricity rate.

How humidifier type affects power consumption

Ultrasonic humidifiers are the most efficient. They vibrate a metal diaphragm to break water into a fine mist and typically use 20 to 50 watts. Running one for 12 hours daily costs roughly $0.50 to $1.50 per month.

Evaporative humidifiers blow air through a wet wick or filter and use 300 to 500 watts. They are less efficient than ultrasonic models but do not produce the white dust that ultrasonic models sometimes leave on surfaces. Monthly cost for eight hours daily is around $1 to $2.

Steam (warm mist) humidifiers heat water to create steam and draw 700 to 1,000 watts — the highest of any type. They are useful for congestion relief because the warm mist can feel more soothing, but they cost $2 to $4 per month for eight hours of daily use. They also pose a burn risk if children or pets are nearby.

Impeller humidifiers use a rotating disc to fling water droplets into the air and typically draw 300 to 400 watts. They are quieter than evaporative models and cost around $1 to $2 per month for typical use.

Comparing humidifier cost to other household devices

A humidifier's power draw is modest compared to common appliances. A 400-watt humidifier running eight hours daily uses about 3.2 kilowatt-hours per month. By contrast, a space heater at 1,500 watts uses 12 kilowatt-hours in the same time. A hair dryer at 1,800 watts uses 14.4 kilowatt-hours in just one hour of use per day.

Even a window air conditioner at 1,000 watts running eight hours daily uses 8 kilowatt-hours — more than double a typical humidifier. A refrigerator running 24/7 at 150 watts uses about 108 kilowatt-hours per month. So while a humidifier does draw power, it ranks low among household electricity consumers.

The only devices that use less are things like a ceiling fan (50 to 100 watts) or a laptop charger (30 to 65 watts). If you are concerned about electricity use, reducing heating or cooling by a few degrees will save far more than turning off a humidifier.

Ways to reduce humidifier electricity use

Choose an ultrasonic model if electricity cost is your main concern. They use a quarter of the power of steam models and still deliver moisture effectively. The trade-off is occasional white dust on nearby surfaces, which you can reduce by using distilled water instead of tap water.

Run the humidifier only when you need it. If you use it only during winter months or when humidity drops below 30 percent, your monthly cost will be lower than running it year-round. Many humidifiers have a built-in hygrometer or can be paired with a separate humidity sensor to turn on and off automatically.

Keep the tank clean and the filter or wick in good condition. A clogged filter forces the motor to work harder and use more power. Evaporative models especially need regular cleaning — a dirty wick reduces efficiency and can increase runtime to reach your target humidity level.

Use a smaller humidifier if you only need to humidify one room. A 1-gallon ultrasonic model uses far less power than a 5-gallon whole-house unit. If you are humidifying a bedroom or office, a compact model will cost less to run and take up less space.

Understanding your electricity bill impact

To see whether a humidifier noticeably affects your bill, check the wattage on the device and calculate the monthly cost using your local rate. If your rate is $0.12 per kilowatt-hour (a typical U.S. average, though rates vary widely by region) and you run a 400-watt humidifier eight hours daily, the monthly cost is about $1.15. Over a year, that is roughly $14.

Most households will not see a meaningful change in their electric bill from running a humidifier. The difference becomes more noticeable if you run a steam model 12 hours daily in a cold climate where you also use electric heating — but even then, the humidifier itself is not the main driver of your heating costs.

If you are on a time-of-use rate plan (where electricity costs more during peak hours), running your humidifier during off-peak hours can lower the cost further. Check your bill to see if your utility offers this option.

Frequently Asked Questions

Does leaving a humidifier on all night use a lot of electricity?

No. A 400-watt humidifier running eight hours overnight costs about $0.10 per night (at $0.12 per kWh). Over a month, that is roughly $3. Even a 1,000-watt steam model costs only about $0.25 per night. The electricity use is minimal compared to heating or cooling your home.

Which type of humidifier is cheapest to run?

Ultrasonic humidifiers are the cheapest because they use the least power — typically 20 to 50 watts. A small ultrasonic model running 12 hours daily costs around $0.50 to $1 per month. Evaporative models are the next most efficient, followed by impeller models, with steam humidifiers being the most expensive to operate.

Will a humidifier significantly increase my electric bill?

Unlikely. A typical humidifier adds $1 to $3 per month to your bill. Unless you run a large steam model 24/7, the impact is negligible. Your heating and cooling system, water heater, and refrigerator use far more electricity and will have a much larger effect on your monthly costs.

Is it cheaper to run a humidifier or a dehumidifier?

Dehumidifiers typically use more power than humidifiers — usually 300 to 700 watts, with some models reaching 1,000 watts or more. Both cost roughly the same to run, but a dehumidifier may run longer because it has to remove moisture from the air, which takes more time than adding it. For cost, neither is a major factor in your bill.

Can I run a humidifier on a power strip with other devices?

Yes, but avoid plugging multiple high-power devices into the same strip. A humidifier alone is fine, but do not pair it with a space heater, hair dryer, or other high-wattage appliance on the same strip, as this can overload the circuit. Check the power strip's maximum wattage rating and add up the devices you plan to use together.