How Much Water Should a Dehumidifier Collect in a Day?

Dehumidifiers are designed to remove excess moisture in the air. This way, users can control the humidity levels in their homes, which is crucial to prevent molds and allergies. But how much water should a dehumidifier collect in a day to ensure that it works?

The quick answer is within 10 to 20 liters, but it’s just a rough estimate. Below, we discuss dehumidifier capacity and speed to know how much water your unit should be yielding.

How much water should my dehumidifier collect?

The amount of water your dehumidifier unit should be collecting isn’t fixed to a single rate. Instead, it depends on a few aspects, including your home’s relative humidity, air temperature, and so on. With this, the amount of water a dehumidifier collects is always on a sliding scale.

Here are a few points that will affect the amount of water your dehumidifier can suck out from the air:

💧Dehumidifier capacity

Nowadays, a portable dehumidifier is designed to collect around 10 to 20 liters of water a day. But if you have a larger unit, this capacity can be as much as 50 liters. So usually, the bigger the dehumidifier’s capacity, the more water it can collect in a day. The desiccant dehumidifier is an exception here.

Aside from that, the dehumidifier’s power level will affect the amount of water it can collect. A dehumidifier with a higher extraction rating will undoubtedly collect more water per day.

For example, a 30L dehumidifier can bring down 90% relative humidity to 40% in just 11 minutes. On the other hand, a 12L unit will take as much as half an hour to reach the same relative humidity. Both of these measurements are done in a 50 sq. ft. room with the same temperature.

💧Relative humidity and temperature

Take note that there are two ways to measure humidity: absolute and relative.

Absolute humidity is measured in mass/volume and refers to the actual amount of water in the air. It’s in the form of water vapor. With this, a high absolute humidity means wetter air.

On the other hand, relative humidity (RH) refers to the amount of water the air can hold under a specific temperature. So when air temperature increases, RH decreases, and vice versa. In short, humidity is measured relative to the temperature. For this part, we will focus on relative humidity.

By measuring the RH of your home, you’ll know how much water should be removed at any given time. This is also the same reason why many room dehumidifiers in the market have built-in humidistats.

Overall, the ideal relative humidity of a room is between 30% and 60%. With this, a dehumidifier will collect more water in a room with 90% RH than a room with 70% RH.

💧Room size

Another thing you should consider is the size of the room where you’re using the dehumidifier. Technically, a dehumidifier will collect more water from a 2,000 sq. ft. room compared to a 500 sq. ft. area under the same relative humidity.

In general, average dehumidifiers can remove up to 25 liters of water in a 2,000 sq. ft. room. This will be more if you’re using large, industrial-grade dehumidifiers.


If we’re going to set aside humidity conditions, most electric dehumidifiers can collect 4 liters of water for about 12 hours. High-powered units can cut this time by as much as half.

Reasons why your dehumidifier isn’t collecting enough water

If you notice that your dehumidifier isn’t collecting enough water, the following might be the reasons why:

how much water should a dehumidifier collect in a day - photo of a hand pressing a dehumidifier button
Photo Credits – Aire Serv

💧Very low temperatures

Temperatures below 18C mean that the air may not have enough absolute humidity. In this case, there’s no need to run a dehumidifier unless you’re keen to lower the moisture level in a specific room even further.

💧Wrong settings

Before you conclude that your dehumidifier isn’t working, it’s important to check the settings first. It’s possible that you set the wrong humidity target.

💧Faulty compressor

A malfunctioning compressor will fail to circulate the refrigerant properly. If the refrigerant isn’t circulated properly, the dehumidifier won’t be able to extract moisture from the air. This requires professional repair, especially if your dehumidifier has been in use for years.

💧Faulty capacitor

If the compressor is in good shape, you may want to check the capacitor of your dehumidifier. This part is also necessary for the pumping of the refrigerant. If this component is broken, there’s a high chance that your dehumidifier won’t collect enough moisture.

💧Problematic fan motor

A dehumidifier’s fan is responsible for funneling air into the machine. This ensures that the refrigerant dehumidifier has enough air to collect moisture from. However, the fan will get dusty and worn out over time. This needs cleaning and lubrication to ensure optimal functions.

💧Blocked air filter

The same with the motor fan, air filters can get clogged with dust and dirt. Many dehumidifiers in the market have washable filters, though some require regular replacements. It’s important to clean or replace the filter to ensure that the dehumidifier can suck in air and moisture.

💧Overheating motor

A dehumidifier that’s been running for days on end will start to overheat and malfunction. You’ll notice the equipment collecting less and less water as time goes by. In this case, it’s important to let the motor rest. Lubricating the fan motor may also be necessary, especially if you’re using high settings.

Why is my dehumidifier filling up faster than usual?

Another possible scenario is the total opposite of the above. Some users also wonder why their dehumidifiers fill up faster than usual. This can be a good thing since it’s a sign that your device is working. However, if there’s a low humidity level, the following might be the reasons why:

🤔Blocked coils

A dehumidifier placed beside a living room chair
Photo Credits – Sylvane

While blocked coils may seem to cause reduced water collection, it can actually result in the opposite. When this part is blocked with dust and debris, the air won’t reach the evaporator coil surface, thus less water collection. This will also cause the refrigerant to freeze the moisture on the coils. It will lead to thick frost.

Over time, the ice will melt and fill your buckets fast. If not addressed right away, the blocked coils will start to cause unnecessary wear and tear on the dehumidifier.

🤔Dehumidifying for the first time

It’s also possible that there’s nothing wrong with your dehumidifier. It just happened that this is your first time dehumidifying a specific area. All the moisture sitting on crevices, surfaces, and cracks will cause the bucket to fill up fast.

Even if the place looks dry, hidden leaks and water damage harbor a lot of moisture. Take note that such moisture left for long periods is a catalyst for mold.

🤔Small bucket

Another possible reason here is that your dehumidifier has a smaller bucket than what you actually need. Basically, high absolute humidity in a large room will have more moisture in the air. But if the bucket is too small, you’ll notice it filling up fast and requiring frequent draining.

It’s quite easy to determine if a specific dehumidifier size is suitable for your home. Basically, a 30L unit will collect 30 liters of water when used for 24 hours. This is measured under the relative humidity of 60% with a temperature of 65F.

So if your room has a higher humidity level than 60%, it means that a 30L unit will fill up faster within 24 hours. I suggest upgrading to a bigger unit, especially if you’re using the dehumidifier regularly.

How to speed up a dehumidifier’s water collection

Dehumidifiers are useful equipment, but they do consume a lot of power. To help speed up the dehumidification process, I suggest the following steps:

  • Ventilate the room first. Before running the dehumidifier, it will help to open the windows and doors first. However, you should only do this if the outdoor air is dryer and won’t worsen indoor humidity. Through this, you can lower the moisture level to some extent.
  • Fix plumbing leaks. Running a dehumidifier in a leak-mired room is a big waste of time and energy. The leaks will keep the lead to a high humidity level. And even if your dehumidifier is large enough to keep up with the amount of leaks, it will be an unending process. It’s important to fix the water leaks before you start dehumidification.
  • Use electric fans first. If your dehumidifier consumes a lot of electricity, you can try to use electric fans first. This will help reduce moisture, so your dehumidifier will have an easier job later on.
  • Dry the laundry outside. If you’re running a dehumidifier, it’s best to dry your laundry outdoors if you want the process to speed up. This way, your equipment won’t have to compensate to cover the excessive moisture evaporating from your clothes.

Frequently Asked Questions

Q: Is it normal to empty a dehumidifier every day?

A: Most dehumidifiers need to be emptied at least once a day. This is especially true for units with small water buckets that get filled up easily. But if you’re only running the dehumidifier for a few hours, it may not be necessary to empty it frequently.

Q: Is it safe to drink the water from my dehumidifier?

A: No, you should never drink the dehumidifier water you’ll collect. The same goes for water you collected from your air conditioner. You should never use it for purposes involving food preparation and ingestion. If you’re thirsty, a bottle of distilled water would be safer.

Q: Do dehumidifiers clean the air?

A: No, dehumidifiers don’t clean the air. This appliance is only made to remove excess moisture from the air based on the settings to which it is set. If you want to clean your indoor air, you should use a home air purifier. Cleaning your house is also crucial in keeping indoor air safe to inhale.

Q: Can I leave a dehumidifier running overnight?

A: Yes, it’s safe to use a dehumidifier overnight. Just make sure that it has a water container big enough to accommodate the amount of water that will be collected. Otherwise, you’ll have to get up in the middle of the night to empty the appliance.

Q: Why is my dehumidifier not stopping?

A: It’s possible that the room still has excessive moisture. Make sure that you set the target humidity properly to avoid over-dehumidifying your house. But if the device is operating beyond the set configurations, it’s probably malfunctioning and in need of repairs.

Final words

How much water should a dehumidifier collect in a day? It all depends on the relative humidity level, the capacity of your equipment, and room size. Therefore, it’s important to size up your dehumidifier based on the area where it will be used. This will give you a better idea of how much water you’ll expect on the bucket.