How Much Water A Dehumidifier Should Collect In A Day

Dehumidifiers extract moisture from the air within a room in the form of water and collect it into a bucket.

The rate at which a dehumidifier collects water can depend on a number of factors and unless it has been set up for continuous drainage then the tank on a dehumidifier will need to be manually emptied.

A dehumidifier should collect on average between 10 and 20 liters of water in a day, but this can vary significantly depending on the type, size and age of dehumidifier and its tank, the local climate, temperature, room size, and current and target relative humidity.

Knowing how much water your dehumidifier should collect can help you evaluate if it’s performing properly and also help determine how often you should expect to empty it.

We know from the owner’s manual of our own dehumidifier that its maximum collection rate is 10 liters per day at a certain temperature and humidity.

Dehumidifier Water Tank
Our dehumidifier can collect up to 10 liters per day

Unfortunately knowing an average collection rate only helps so much as all dehumidifiers are built and work differently in various scenarios and climates.

Keep reading for a look at how to judge how much your dehumidifier should be collecting.

What Affects How Much Water A Dehumidifier Collects?

Due to the large number of variables that can affect how much water can be collected, you shouldn’t expect every dehumidifier to collect the same amount of water.

Several factors impact how much water a dehumidifier gathers:

  • Type of dehumidifier
  • Size of dehumidifier
  • Relative humidity in the room
  • Temperature in the room
  • Size of the room

All of these elements will dictate how much water your dehumidifier collects during any given day.

Type Of Dehumidifier: Refrigerant vs. Desiccant

They are two general types of dehumidifiers that you can buy to help lower the humidity in your home: refrigerant and desiccant.

  • Refrigerant dehumidifiers use a heat pump and heat coils to heat and cool air to collect condensation.
  • Desiccant dehumidifiers use a material, such as silica gel, that will absorb water.

Although both types of dehumidifier do the same thing, they extract moisture in different ways and can actually collect more or less water depending on the climate their used in.

Refrigerant dehumidifiers can be more suited to hotter climates while desiccant dehumidifiers can be more suited to colder climates (because there are no coils that can freeze over).

We live in a colder climate and use a desiccant dehumidifier.

Our own desiccant dehumidifier

However, family members also use the refrigerant type.

The refrigerant dehumidifier we also have

Both types of dehumidifier will typically collect roughly the same amount of water when used in their intended conditions.


Dehumidifiers come in a range of sizes, and that size will naturally affect how much water it should collect.

The smaller the dehumidifier, the less water it will typically be able to hold.

There’s also another reason that size matters besides the size of the collection bin. A larger dehumidifier uses more power and can process more air at a time. This means that it can be more efficient and collect water faster than a smaller dehumidifier.

How do you know how much water your size dehumidifier should be collecting?

Dehumidifier sizes indicate how much water they should remove in a day.

Thus, a 30-pint dehumidifier is supposed to remove 30 pints a day while an 80-pint dehumidifier should remove 80 pints.

Seems simple enough, but it is crucial to realize that these numbers come from controlled lab tests. In your home, there are some things besides size that will affect how much water your dehumidifier actually removes in a day.

The manual to our dehumidifier also states that it can collect up to 10 liters a day (every 24 hours) at the perfect conditions of 60% relative humidity and 20 degrees Celsius (68 F).

Dehumidifier Water Level
The water tank on our dehumidifier half full after 8 hours of running

The 6.5 liter water tank on our dehumidifier therefore typically fills up in around 16 hours or so (see our other article on how quickly a dehumidifier fills up for more information).

Relative Humidity

One of the biggest things that affect how much water your dehumidifier collects is how much moisture there is currently in the air.

The relative humidity is a percentage that tells how much moisture is in the air relative to how much moisture the air can hold. 70 percent relative humidity means that the air has 70 percent of the water vapor it can hold at that temperature.

Thus, the higher the relative humidity, the more water vapor there is for your dehumidifier to collect.

The same dehumidifier operating in a room with 70 percent relative humidity will collect far more water than it would in a room with 30 percent relative humidity.

You can buy a device called a humidistat to track the relative humidity in your home, or dehumidifiers will typically state the current humidity on the appliance itself.

As humidity lowers it can become harder to extract moisture from the air

Remember those ideal conditions that dehumidifiers are tested in to determine their daily pint size? The relative humidity of those tests is around 60 percent.

If the relative humidity in your home is less than that, you should expect the dehumidifier to collect less, and if it is more the dehumidifier may collect more.


Temperature doesn’t quite have as large of an effect as other factors, but at a certain point, it can become a major hindrance to your dehumidifier’s collection abilities.

  • Refrigerant dehumidifiers cool air to create condensation.
  • If the temperature in the area where the dehumidifier runs drops below 60 degrees Fahrenheit, the condensation will freeze on the coils.
  • Not only will this stop your dehumidifier from collecting water, but it can also damage the appliance.

You should also consider the fact that cooler air is naturally less humid than warmer air.

As the temperature drops, the air gets drier, so there may not be as much moisture for your dehumidifier to collect.

Room Size

Another thing to consider when thinking about how much water your dehumidifier should collect is room size.

A dehumidifier will be able to reduce humidity levels in a smaller room more efficiently and faster and will therefore start collecting less water as the relative humidity drops.

You should therefore expect a dehumidifier location in an open area such as a hallway to be less efficient than if it was placed in a room with the door and windows closed, but it may collect more water overall because the humidity isn’t dropping as quickly.

Small rooms with closed doors and windows can offer the most efficiency for a single room but less overall moisture collection across a whole house

Why Does Dehumidifier Water Collection Matter?

It can be tempting to simply turn your dehumidifier on and forget about it, but there are a couple of reasons this is a bad idea.

The amount of water your dehumidifier collects can affect:

  • How often you should empty your dehumidifier
  • How much money you spend by running your dehumidifier
Using a small dehumidifier in high humidity can lead to seeing the tank full indicator light more often

You should therefore be paying attention to how much water your dehumidifier collects.

Knowing When To Empty

You have to do something with the water your dehumidifier gathers. Most dehumidifiers that collect water require you to manually empty the tank, although some can use a hose that allows for automatic clearing.

If your dehumidifier is filling up too fast, then you may find yourself needing to empty the tank multiple times a day.

In general, you want a tank size that can accommodate the amount of water your dehumidifier collects in a single day.

Therefore, if you live in a particularly humid climate, you should expect your dehumidifier to collect more than its daily average, so you may want to purchase a slightly larger size.

Dehumidifier Emptying Water
You’ll need to empty the water tank before a dehumidifier can continue running

Saving Money

On the flip side of that is cost. Dehumidifiers use electricity, so running one all the time will significantly impact your power bill.

This means that simply getting the biggest dehumidifier you can is probably not the best idea. You want a dehumidifier that will fill up once a day.

Also, to avoid increasing your power bill, you should avoid running your dehumidifier all day.

Times of low general energy consumption such as early in the morning and late at night are ideal as your dehumidifier will be able to draw power easier. Aim for running your dehumidifier for around seven to eight hours a day.

If your dehumidifier is barely filling up in that time frame then it might be too large or the relative humidity in your home may already be quite low.

How Much Water Should A Dehumidifier Collect In A Day?

Dehumidifiers come in many sizes, and you want yours to be as efficient as possible.

High relative humidity and smaller spaces will cause your dehumidifier to collect more daily, while colder weather and low relative humidity can have the opposite effect.

On average, a standard home dehumidifier should be able to collect between 10 and 20 liters per 24 hours.

Our own dehumidifier collects up to 10 liters a day but we don’t live in a very humid environment. This is all we need however to help keep our home at a comfortable humidity.

You should run your dehumidifier so that it needs to be emptied once every one or two days. More than that, and you may need a bigger dehumidifier. Significantly less than that, and your house may be dry enough, or you may need a smaller dehumidifier.

Further Reading

How Quickly Does A Dehumidifier Fill Up?

Do You Need A Dehumidifier For Every Room?

What Are The Settings On A Dehumidifier?