Why a Portable Air Conditioner Often Fills with Water

If you have recently purchased a portable air conditioner and it often fills with water when you use it for long periods of time, here are some reasons why this is happening.

First, let's take a look at why there is water inside a portable AC at all.

The cooling process of portable air conditioners is refrigeration-based and as such, it produces water in much the same way that all compressor-based refrigeration appliances do. That is, the vapor compression cycle that causes moisture in the air to condense on the cold coils.

Humidity and other factors affect the amount of water produced. A portable AC that fills up with water too fast can be a problem.water spill

The Problem

It can be a nuisance to have to drain your AC's condensate tank every few hours or so, more so at night. After a long, hard day's work, you need to get a restful night's sleep.

Many portable air conditioners feature self-evaporation technology. The water is automatically evaporated through the vent hose.

This technology is not available on all portable ACs. Even though your AC can automatically expel water, most ACs are only partially evaporative.

They still have a water tray. The water tray serves the purpose of holding water so that it does not get ejected at the same rate it is being generated.

Why Does Your Portable AC Fill Up with Water Quickly?

Humidity in your area is a major reason why your romm AC unit fills up with water too fast.

A dirty filter or clogged condensate lines can also cause excessive water deposits. Clogging can cause water to freeze and build up over the coil of the evaporator, eventually melting which in turn causes the water container to fill faster.

Let's look at some of the main reasons for that AC water tank to keep filling so often.

High Humidity in Your Area

Your portable air conditioner generates water by condensing humidity. The humidity of the air is directly proportional to how much water it produces.

High humidity areas will result in more water accumulating in your portable AC's condensate tank. In Texas and Louisiana for example, the average relative humidity is around 75 percent.

This is a very high level of humidity and makes them among the most humid states in America.

If you live in these areas of the US, or in any similar regions around the globe, you will need to empty your water pan quite a few times.

Manual drainage is not required so much in places that have low humidity, such as Arizona or Nevada where the average relative humidity can be lower than 40 percent.

The majority of portable ACs can be used in places where condensate is not an issue. This is because most of the moisture that has accumulated is automatically expelled.

If you're thinking of buying a portable AC, consider what type you prefer. You can use a portable AC with self-evaporative technology in low humidity areas.

This will ensure that you don't have problems with recurring draining. To avoid interruptions and inconvenience in humid areas, a portable AC that is partially or fully evaporative is the best choice.

The Humid Season

The relative humidity can vary between cities and regions. It also depends on the time of year that your air conditioner is being used.

Some days are more humid than others. This higher water production on certain days could be due to seasonality.

The state and the city you live in will determine when the humidity levels are highest and lowest. In New York, for example, September is the most humid month while April is the least humid.

A portable air conditioner will produce more water in New York City around September than April.

It is possible that the humidity is not accumulating large amounts of water suddenly. Because the weather has no impulsive effect on humidity, the effects of the weather on the air are not immediate.

The variation in humidity isn't too large. If you notice a lot of water being generated by your AC portable on a particular day, it could be a sign that there is another problem.

Dirty Air Filter

After it passes through an air filter, the air cools down and is then delivered to your living space. The filter blocks dirt and dust from the air.

After cooling, filter must be removed. The quality of the air passing through the filter will determine how long it takes to clean.

A dirty filter is one of the reasons a portable AC fills up with condensate. An air conditioner will stop working if the filter is clogged with debris. Air flow will decrease and less air will pass through the coil.

The moisture in the air will be frozen and will continue to drip into the condensate tray. Even with a portable AC that is partially evaporative, the water won't evaporate at the same speed as it drips so you will need to continue emptying it.

Many air conditioners include a filter reset indicator. The indicator turns on when the filter becomes dirty or after a certain number of hours.

The company determines the time that the filter reset light will turn on. You must remove the filter and clean it before your air conditioner can turn on.

Make sure to check the air filter on your AC portable. Clean the filter if it needs it. Air conditioner filters are nearly always reusable, so it may not be necessary to replace them.

To wash the filter, use lukewarm water. Before you insert it back, let it dry completely.

Faulty Condensate Pump

A condensate pump is a simple way to eliminate all condensate. Condensate pumps are able to direct the water from the water pan to the desired location. It is easy to set up.

Condensate pumps can leak water or fill up too quickly. Either the condensate pumps are defective or the drain hose that enters or exits the pump is bent or blocked.

This will stop water from flowing. It is a good idea check the pipe before and after condensate pumps.

A condensate pump is a great option if you don't mind draining your AC. It's very simple to set up. Simply attach the drain tube to your AC and then connect it to the condensate pumps.

Connect the condensate pump to an electrical source. It will continue to collect water until it reaches a certain level.

Once that level has been reached, the pump will turn off and water will flow to the desired place.

The drain hose can be run directly to another location, and water may drain without the need for a condensate pumps. It will only do this if gravity is present.

This method won't work if water must travel in an upward direction (against gravity). This problem can be solved by this device. Water may be pumped to another place against gravity.

A condensate pump is the best and most efficient way to do this. It is a great choice if you are looking for something to go along with it. Click here for more information.

Portable AC Recently Purchased

A portable AC that is producing a lot water after being newly installed is an indication of a potential problem.

Air conditioner companies care about their reputation and will sell the unit at a premium. Because there is so much competition, they cannot afford to damage their reputation.

You can return your portable AC if there is any damage or problem during delivery.

It could be the high relative humidity in your area, or it could be that you bought a new unit. Air conditioning removes humidity from the floor, walls, ceiling, and furniture in your living area.

This could lead to high water levels in the water pan. If your water pan is constantly full, you should test your portable AC.

Give it time before returning it. If the water pan keeps filling, it could be a problem with the AC or that it isn't suitable for your area.

High average relative humidity. This means you may want to look at other types of portable AC such as fully evaporative and partially evaporative.

Water Not Draining Properly

portable air conditioner drainingThe simplest way to drain water from your AC portable is to drain it manually. To do this, you'll need to take out the drain plug. Then let the unit drain into an empty container.

It will depend on how humid your area is and how long your AC has been running. This could take anywhere from 6-8 hours up to several weeks.

This basic method will tell you if there is a problem if you drain manually. If your AC is not draining, it may indicate that the water tank is full.

However, no water is coming out of the drain plug. A clogged drain could be the reason water is not coming out of your water tank. It is unlikely that anything would block it from the outside so it could have been something from the outside.

If you're using a drain tube to remove water from your portable AC by gravity or condensate pump, you should not fill up the water tank. Blockage of the drain hose is the most common reason.

You should inspect the drain hose for bends, especially those that are 90 degrees. If you have a condensate pump, make sure to inspect the pipe that runs through it.

How Often Do You Need to Drain Your Portable AC?

There are many factors that affect the frequency of draining your free standing AC within a given day.

It is dependent on the humidity, hours of operation, and type of portable AC. An air conditioner with self-evaporating technology will remove most humidity through the vent when it exhausts warm air.

Many modern room AC models on the market use self-evaporation technology. The portable AC can be divided into two types: Fully evaporative portable AC or partially evaporative portable AC.

Many modern portable AC models are partly evaporative. If you just purchased a portable AC, and don't know which one it belongs to, it most likely is partially evaporative.

Portable AC with Partially Evaporative Technology

A lot of portable ACs on the market today are partially evaporative. They can also be used with partial self-evaporation technology.

They will still retain some humidity from the cooling process. They must be drained as needed depending on the humidity level, unless one of the problems listed above.

Portable AC with Fully Evaporative Technology

The fully evaporative portable AC that is can remove humidity completely from the air. This type is the best option if you are looking to eliminate all hassle.


There are many reasons why a AC portable can be producing so much water.

The main reason water accumulation is due to relative humidity. There are many things you can do to control the humidity, such as a dirty filter or a faulty condensate pump. If humidity is not a problem, give them a look.

Consider the climate in the area you live and the type of AC you are using. You can modify your AC to drain through the hose with gravity or condensate pump if humidity is high.

Posted: August 18, 2021

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Customer Comments

  • Angela: Hi, I'm from the Tropics. It is extremely humid here at 80%. My portable AC has been acting up since last week. The AC keeps indicating that the excess water tank has filled and I must empty it every 30 minutes. This has never happened before. Air filters are cleaned every two weeks. The air filter is now very clean, but the water remains in excess. It is unusual for me. Let me know if you have any other ideas.
  • Mark: As most portable ACs on the market, I presume that your AC is partially evaporative. This is an abnormal situation. Water can quickly start to collect, so it is possible that the evaporator coil has become clogged or the flow of air has been reduced or blocked. This generates ice, which then fills the container. If your AC is new, it is a good idea to contact customer service first. You can also use an external accessory such as a drain hose or condensate pump to temporarily resolve the problem.