How Much Water Should a Dehumidifier Collect In a Day?

Wondering how much your dehumidifier can handle? Dehumidifiers are useful appliances for reducing the humidity in your home but they do have limits, so it’s important to understand them.

I’ve used a wide variety of dehumidifiers in residential and commercial settings, and the amount of humidity your dehumidifier can manage depends on a few key factors. In this guide I’ll answer the question ‘how much water should a dehumidifier collect in a day?’, explain how they collect water, and show you what you can do to get the most from your dehumidifier.

How Much Water Does a Dehumidifier Collect per Day?

Haier Dehumidifier Sample

An average-sized dehumidifier will collect 15-20 liters of water a day if it’s used in a residential space. Commercial dehumidifiers are generally more effective at moisture extraction and can collect up to 50 liters a day.

The actual amount of water that your dehumidifier collects in a day depends on several factors:

  • Tank capacity – how much water/water vapor can actually fit in the tank before it shuts off
  • Humidity levels – how much moisture there is to be extracted
  • The efficiency of your dehumidifier – how quickly it extracts moisture from the air. The average rate of dehumidifier collection is approximately 12 to 13 hours for a 4-liter container.

How Does a Dehumidifier Collect Water? (How it Works)

Dehumidifiers collect water by drawing in damp air, extracting the moisture, and then releasing the dry air back into the room. The moisture from the air is then collected in a water tank or water reservoir. By extracting this moisture the dehumidifier lowers the relative humidity levels in the room and improves the indoor air quality.

The higher the humidity level, the more water your dehumidifier will collect because the longer it will need to run to lower the overall humidity level. The efficiency of your dehumidifier can be measured by the amount of water it is able to drain over one hour.

There are two main types of dehumidifiers and the way each type of dehumidifier collects water is slightly different:

Refrigerant/Compressor Dehumidifiers

Most dehumidifiers are refrigerant dehumidifiers. Refrigerant/compressor dehumidifiers work by bringing in moisture through the air by sending the air through a filter and then over cold coils. These coils lead to condensation that creates water and falls into the water tank.

Refrigerant dehumidifiers work well in most temperatures and use less energy. They work well in locations with high humidity seasons and high moisture levels because they’re cheaper to run for longer periods.

Desiccant Dehumidifiers

The desiccant type of humidifier works by directing the air over an absorbent material. The humidity in the surrounding air is captured on the absorbent material and dry air is released back into the room. The absorbent material is then heated within the dehumidifier so that moisture will form. As moisture forms, it slides down the absorbent material and falls into the water tank.

Dehumidifiers work best to maintain humidity levels in lower temperatures because they don’t have cold coils so there’s no risk of freezing. The dehumidifier costs are higher though because they are less energy efficient.

Water for Dehumidifier

Factors Affecting the Amount of Water the Dehumidifier Can Collect

Dehumidifiers Capacity

The dehumidifier’s capacity is basically the dehumidifier fill rate. The capacity determines how much water the dehumidifier can create from the air as it draws moisture in. The greater the capacity of the model, the more water the dehumidifier can bring in a day, so if you have a lot of moisture then you need a high-capacity model.

Average Humidity

The greater the level of humidity in your home and environment, the more water the dehumidifier will collect. This is simply because you have more water to collect in your environment and areas that are lower in humidity [1] will not need to have as much water collected in order to lower the relative humidity level.

Advanced dehumidifier models have humidity settings and humidity detectors that tell you how much moisture needs to be removed. Use this to guide when and where your dehumidifier needs to be used.

Air Temperature

The air temperature also plays a role in the amount of water collected by your dehumidifier. At warmer temperatures, dehumidifiers tend to work better because it helps contribute to condensation.

If you live in a warmer environment, you are more likely to collect higher volumes of water each day. This also means that you will need to empty your dehumidifier more often than someone who lives in a cooler climate.

Room Space

The amount of water collected also depends on the room space in your home. If you are using a whole-house dehumidifier, for example, then a large amount of water will be collected.

Portable dehumidifiers are smaller, and although they work well, they cannot collect as much water or collect it as quickly. The size of your dehumidifier will affect how much water is collected daily.

How Long Does It Take for a Dehumidifier to Fill Up?

Keystone Dehumidifier Sample

It takes approximately 2-18 hours to fill up a dehumidifier tank. This varies depending on the size of the tank and the capacity of the unit to pull moisture from the air.

The size of the tank is the amount of standing water the dehumidifier can hold before it needs to be emptied.

The dehumidifier capacity is how much water it can extract in a 24-hour period. This is expressed in pints (e.g a 30-pint dehumidifier) and is usually more than the size of the tank.

Dehumidifiers have different capacity levels. The capacity refers to the amount of water that the unit can remove from the air.

The higher the capacity of the model (the greater the number of pints shown), the more excess humidity is extracted, and the quicker the dehumidifier will fill up.

For example, a dehumidifier at the 35-pint capacity that takes the room from 90% relative humidity to 40% relative humidity would take 17 minutes. A 50-pint capacity model could do the same thing in 11 minutes.

Below is a table for how long it will take to remove the excess humidity from your home. Remember, you may have to let your dehumidifier fill up several times over before you reach the optimal humidity levels.

Capacity Amount (Pints)90 to 40% Relative Humidity80 to 50% Relative Humidity
22 Pints34 Mins15 Mins
35 Pint17 Mins8 Mins
50 Pint11 Mins6 Mins

What Happens If Your Dehumidifier Tank Is Full?

If the tank is full then most room dehumidifiers and portable dehumidifiers will automatically turn off. This can lead to an increase in humidity and a drop in your indoor air quality. You may also feel a rise in the ambient temperature in the room.

If you notice your dehumidifier stop collecting water it’s a clear sign you should empty it. You’ll need to empty the tank before you can use the dehumidifier again.

How Often Should You Empty Your Dehumidifier?

Your average dehumidifier should be emptied once or twice a day. This is enough for typical dehumidifier performance, but if you’re using a very efficient model and have a lot of humidity then you may need to fill it up more quickly.

When you first purchase your dehumidifier, make sure that you monitor how quickly the tank is filling up. Once you know how long it takes to fill up, you can easily check on your dehumidifier and empty it accordingly.

Why Is Your Dehumidifier Filling Up So Fast?

If you notice that your dehumidifier is filling up more quickly then it could mean there’s a water leak or cracked pipe in the room causing higher relative humidity levels than usual. Keep an eye on what your dehumidifier will usually collect in a day, and if the moisture levels increase noticeably you should look for the source.


Why is my dehumidifier running but not collecting water?

If your dehumidifier is running but not collecting water, the most likely problem is with the fan motor or internal coils. The cold coils are needed to create the condensation and a fan is needed to draw air in. Make sure both your coils and fan are operating normally so the dehumidifier can reduce the humidity levels properly.

How to fix a dehumidifier that is not collecting water?

If your dehumidifier is not collecting water start by emptying the tank, unplugging the dehumidifier, and then re-plugging it back in. If it still won’t work, try to determine whether or not the interior coils are getting cold and check whether the fan is working. If you cannot identify the problem, it is time to bring in a professional or purchase a new unit.

Is water collected from a dehumidifier safe to drink?

You should never drink water from a dehumidifier. Your dehumidifier will collect clean water, however, the water sits in a tank containing bacteria, dust mites, mold, and other potential pollutants which could be harmful to your health. We definitely recommend not drinking the water from your dehumidifier.

Do you have to drain a dehumidifier?

Yes, you do have to drain a dehumidifier. Most units come with a removable tank, so you can simply remove the tank and drain the water outside or in your sink. Depending on the size of the tank and the level of humidity in your home, you may need to do this 1-2 times per day or 1-2 times per week.


How much water should a dehumidifier collect in a day? On average, 10-20 liters but it entirely depends on the humidity levels and amount of excess moisture in the air and the capacity of the dehumidifier.

Remember, your dehumidifier can usually empty more than 1 tank of water vapor in a day so you’ll need to empty it frequently to get the best results. Hopefully, this guide has helped explain what you should expect from your dehumidifier and will help you spot if something isn’t right.


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Last Updated on February 6, 2023

Josh M