How Much Do Dehumidifiers Cost to Run?

An indoor air quality plan is incomplete without a dehumidifier. But when I started researching about dehumidifiers, I quickly realized that they use quite a substantial amount of electricity.

So how much do dehumidifiers cost to run? Generally, dehumidifiers cost between $25 to $350 a year ($2.08 to $29.16 per month) in electricity for most residential homes. The $25 cost usually applies to mini dehumidifiers, while the $350 cost applies to larger units that can take up 70 pints of moisture from the air per day.

The range between $25 and $350 is quite large, so let’s take a look at where your energy bill might fall once you actually purchase a dehumidifier.

Energy Star Rated Dehumidifiers Save You Up to 30% Per Year

I hope you’re thinking about getting a dehumidifier that’s been Energy Star certified. If you already have one and are wondering if your energy bill is high, remember that your monthly energy bill could’ve been 30% higher had you chosen a similar dehumidifier that didn’t have the rating.

But how does the rating actually work?

Each dehumidifier’s capacity is measured by how many pints of moisture it can remove per day. The energy star rating system divides dehumidifiers into two categories based on this capacity. The dehumidifier then undergoes a series of tests and is assigned an energy factor, or EF.  You may also see this labeled as EEV. This basically is a representation of how many liters of water the dehumidifier can remove per each kilowatt-hour of energy it consumes.

The two categories are quite straight-forward:

• If Product Capacity (Pints/Day) is < 75, then Energy Factor (L/kWh) must be > 1.90.
  If Product Capacity (Pints/Day) is 75 < 185, then Energy Factor (L/kWh) must be > 2.80.

For most homes, the EF value is typically around the 1.90 to 2.00 range. Sure, there are some dehumidifiers that are 2.50, or even 4.00 EF, but those are the commercial kind that cost thousands of dollars and remove 130 pints of water or more.

The average home will rarely need a dehumidifier that size, so I won’t talk about them here.

What Is the Cost of Running a Dehumidifier 24/7 (and Does It Need to Be On All the Time)?

Many people assume that a dehumidifier runs 24 hours a day and 7 days a week.

But your dehumidifier doesn’t have to run constantly!

As long as you match up the capacity of the dehumidifier to the size and conditions of the room, you’ll quickly learn that it will automatically turn itself off once the right humidity level is reached. In a realistic scenario, this generally means that you’d be running your dehumidifier only 12 hours a day, while it rests the other 12 hours.

The only reason why a dehumidifier will never shut off is because it’s unable to control the space (it’s a little like trying to force a scooter to reach the speed limit on the highway). So, if you bought a standard 20-pint dehumidifier for that extremely damp 65 °F basement, I’m sorry to tell you, but you bought the wrong dehumidifier. The coils are probably frozen, and it’s just blowing air through constantly, waiting to break down on you one day.

How to Calculate Your Energy Bill Before You Buy a Dehumidifier

A lot of factors will affect your energy bill, so there is no way to know exactly how much adding a dehumidifier will add to your energy bill until you actually buy it. But there are some rough calculations you can make.

You’ll need to find out two things.

First, you’ll need to find out how much your utility company charges per kilowatt hour (kWh). Look at your bill in detail – there are some fees added sometimes to each kWh, so look for those. I’ll use $0.14 per kWh here since that’s how much I’m being charged.

Second, you’ll need to know just how much power your dehumidifier will draw in Watts (W). Look through the product descriptions or online user manuals to find this. If given voltage and amperage, simply multiply those two numbers for a rough estimate. Convert this number to kilowatts (kW) by dividing by 1,000.

Once you have those two numbers, simply multiply them by each other to get an estimate on how much it will cost to run the dehumidifier per hour.

In the comparisons below, I have calculated how much the dehumidifier would roughly cost to run 24, 12, 8, 6, or 4 hours a day. When idle (meaning it’s off or just the fan is running), the amount of power used by the smaller dehumidifiers is negligible. The mid-size to larger units will use about 20 to 30 W per hour, which translates to about 8 to 12 cents per 24 hours.

Let’s take a look at the calculations.

Dehumidifier #1:

hOmeLabs Small Dehumidifier (Compact Dehumidifier, HME020018N)

Claimed water removal capacity:

• 0.53 pints (250 mL).

Energy Star rating:

• No.

Power usage:

• 22.5 W.

Energy bill estimate:

Does this one fit your energy budget? Check price and read reviews on Amazon.

Dehumidifier #2:

Ivation IVADM35 Dehumidifier

Claimed water removal capacity:

• 1.27 pints (600 mL).

Energy Star rating:

• No.

Power usage:

• 72 W.

Energy bill estimate:

This unit is great for small areas. Check its price on Amazon.

Dehumidifier #3:

Pro Breeze Electric Mini Dehumidifier

Claimed water removal capacity:

• 2.7 pints.

Energy Star rating:

• No.

Power usage:

• 150 W.

Energy bill estimate:

I really liked the modern, white design of the ProBreeze and its quiet Whisper technology. Check it out on Amazon.

Dehumidifier #4:

Black and Decker BDT30WTA Dehumidifier

Claimed water removal capacity:

• 30 pints.

Energy Star rating:

• Yes (2.00 EF).

Power usage:

• 295 W.

Energy bill estimate:

If you’re looking for a dehumidifier for a large room or a small basement, this is a good one. Again, it’s on Amazon.

Dehumidifier #5:

Frigidaire FFAD3033R1 Dehumidifier

Claimed water removal capacity:

• 30 pints.

Energy Star rating:

• Yes (2.00 EF).

Power usage:

• 320 W.

Energy bill estimate:

I’m not a big fan of the casters and the bubbly design, but I absolutely had to recommend the Frigidaire (yes, it’s on Amazon) with its 7,000+ great customer reviews and a great database of over 1,000 answered questions.

Dehumidifier #6:

Honeywell DH50PW Dehumidifier

Claimed water removal capacity:

• 50 pints.

Energy Star rating:

• Yes (2.00 EF).

Power usage:

• 515 W.

Energy bill estimate:

For moist, large basements, you’ll have to start looking into 50-pint units. Check the Honeywell price on Amazon, too.

Dehumidifier #7:

Frigidaire FFAP7033T1 Dehumidifier

Claimed water removal capacity:

• 70 pints.

Energy Star rating:

• Yes (2.00 EF).

Power usage:

• 745 W.

Energy bill estimate:

This is the big one of the Frigidaire line of dehumidifiers, but you have to have a very big basement or a ton of square footage to really need it. In case you do, save yourself some time trying to find a unit this big locally and just get it on Amazon.

How You Can Use This Information

These estimates should just be a general guideline. Just because an estimate says that a dehumidifier costs $1.75 to run per day doesn’t mean that this will be exactly what you’ll see on your electricity bill, to the penny.

Depending on your home environment, you’ll notice that the dehumidifier runs constantly at first. Not only does it need to get the humidity out from the air, but it also removes the moisture from the furniture, cabinets, walls, and other surfaces later on. It may take a few weeks (maybe even a month or two) for your dehumidifier to get the humidity down to a manageable level.

That’s why your first energy bill will probably be the most expensive one.

Once the dehumidifier has started to maintain the setpoint humidity level, you’ll notice that the fan runs more frequently on its own and that the unit shuts itself off for hours in between each cycle. That’s when your dehumidifier will ideally run for about 4 to 12 hours a day.

The season and weather also impact your energy bill. The dehumidifier will be on constantly during a rainy day. Since the dehumidifier blows warm, dry air after it completes the water extraction process, this can benefit you in the winter but not in the summer.

True, your air conditioner should in theory run less since the dehumidifier will help extract water from the air (something the air conditioner would have to do by itself otherwise), but it still needs to deal with the warmer air coming from the dehumidifier. In the winter, the warm air coming from the dehumidifier helps heat the home, so you’ll notice that your furnace will turn on less frequently to heat the home.

It’s impossible to predict just how many hours a dehumidifier will run per day on average. The Department of Energy (DOE) states that the dehumidifier will virtually be off in the winter, and then run between April and October. Here are the total number of hours the DOE estimates a normal dehumidifier will run:

(source)

Using the table above, we can conclude that overall, a dehumidifier will run for 1,095 hours out of the total 8,760 hours that a year has. That averages out to only about 3 hours a day. This is unrealistic for most homes, however, since it assumes something called the AHAM standard (I will discuss shortly below).

That’s why I have highlighted 8 hours in the above estimates in red text, as that is a much more realistic daily running time.

The best way to get the active running time to as low as possible is to buy a dehumidifier that’s just the right size for your home, but how do you do that?

Picking the Right Size

If you buy a dehumidifier that’s the wrong fit for the room, your dehumidifier will be on constantly. Be careful about trusting what the manufacturer recommends as the proper size of the room. You’ll often come across dehumidifiers that are advertised to work in 3,000 or 4,000 square feet spaces or more but make sure you know what that means.

Be careful with mini dehumidifiers (#1, #2, and #3 from the examples above). It may be enticing to buy a dehumidifier that runs on only a few dollars of energy every month, but you really need to know what you’re getting and what your needs are.

Airflow

Find the user manual or product specifications and look for what the cubic feet per minute (cfm) number is. This tells you how powerful the dehumidifier’s fan is at moving the air inside a given space. In other words, it’s a measure of airflow. If this number is low, sure, the dehumidifier may eventually cycle all the air in the room, but do you really want it to be running all day to achieve this?

The higher the cfm, the less time the dehumidifier needs to cycle the air in a room. The time that a dehumidifier can cycle the air inside a room per hour is called the ACH (air change rate). Being able to cycle air more frequently at a faster rate translates to the dehumidifier using less energy and spending more time in idle mode.

When looking at airflow, look for units in cubic feet per minute. Sometimes manufacturers use cubic meters per hour, so you’ll have to convert to cubic feet per minute to be able to compare dehumidifiers correctly.

The Starting Humidity Level

Airflow is especially important for damp basements and bathrooms. A low ACH combined with a moist basement will be a disaster on your energy bill. The dehumidifier will constantly be on!

For normal rooms, look for ACH rates that are a 3 or 4, meaning that the air cycles once every 15 to 20 minutes. For damp areas, look for ACH rates that are 5 or 6, meaning that the air cycles once every 10 to 12 minutes.

As you can tell, the starting level of humidity is important. It takes more work to take the air from a 90% to 50% humidity level than it does to do it from 65% to 50%. If the manufacturer recommends a dehumidifier for use in a 500 square feet room (4,000 cubic feet if it has an 8-foot ceiling), remember that this is most likely for a room that’s only slightly damp.

If the room is extremely damp, a 14-pint dehumidifier capacity that was recommended for a 1,000 square feet space suddenly can only work in a space of 500 square feet.

Temperature

The warmer the ambient temperature is in a home, the more efficiently the dehumidifier works. Unfortunately, this is something that manufacturers use in order to show their dehumidifiers to be more efficient.

Most dehumidifiers are tested at a temperature that’s a bit warmer than the temperature that most people set on their central thermostat.

In fact, the temperature of a room is even more important than the starting relative humidity (RH) when it comes to dehumidifiers.

Dehumidifiers can be rated based on a standard called AHAM DH-1, which is named after the organization that sets it (Association of Home Appliance Manufacturers). When dehumidifiers are tested under AHAM, it means that they’re tested in a closed space with a relative humidity (RH) of 60% and a temperature of 80 ºF.

The DH-1 test also includes Energy Star criteria, so the AHAM standard is generally considered as a good one. It’s also voluntary, so manufacturers that subject their dehumidifiers to AHAM testing are seen as more transparent by consumers. But the problem is that most homes aren’t generally kept at 80 ºF.

Don’t think that it matters?

Let’s take a look at how a dehumidifier performs comparing the AHAM standard (80 ºF) to a similar European standard, which uses 86 ºF as the test temperature (you can find them online just by doing a basic Google search):

Based on this, you should be able to tell that a dehumidifier can initially remove more water if it’s in an environment with high temperature and high starting humidity levels.

This phenomenon is by no means exclusive to the examples listed above. All traditional dehumidifiers are generally able to remove more water from the air at high temperatures and humidity levels. It has to do with the coils inside the dehumidifier that turn the gaseous water into condensate.

At lower temperatures, frost tends to form on these coils, making the unit less effective at collecting water. It’s also easier to draw water from the air when there’s already a lot of it in the air (meaning that there is more saturation).

That’s why it’s so important to realize where your own room fits in on this spectrum and to know what the manufacturer’s suggestions really mean for your situation.

Oftentimes, it’s a good idea to pick a dehumidifier that’s larger than what’s recommended for the room. It might be strange to pick a 50-pint dehumidifier for a damp basement that only has 1,000 square feet. But if the temperature of the basement is 68 ºF or lower, you’ll need a dehumidifier that’s powerful enough. Otherwise, the coils will freeze over and the unit will constantly run without producing any results.

For those rooms, look for features that the coils will be able to withstand cold temperatures, such as advanced defrost functions and pipes that use copper and won’t corrode, for example.