How Often Do You Need To Drain A Portable Air Conditioner? [Solved!]

A portable air conditioner is a great device for cooling the house. It would also be a good supplement to the central ac. However, it will collect water during the operation, and you need to drain it every so often. 

So, how often should you drain your portable ac? Which factors will affect the frequency? Is it possible to avoid draining it completely?

Continue reading! All of these questions have been addressed in this post.

How often should a portable aC be drained on average?

It is difficult to provide a clear, single-cut answer to this question because it is determined by a variety of factors. However, if you’re looking for a ballpark figure, draining the water from a portable air conditioner every 8 hours can almost guarantee that your machine will stay in top shape.

But for you, you may only need to drain the water once during the whole summer. I will explain why the difference is so significant in the following section.

Factors that decide how often you should drain your portable ac

Even if you and your friend have the same portable AC, the frequency of draining water may differ. You will understand why it occurs after reading this section.

Humidity level

This is the crucial factor that affects the frequency of draining water. This is due to the fact that the portable ac lowers the air temperature through condensation on the evaporator coil. 

When the temperature of the air falls below the dew point, the moisture in the air condenses at the same time.

While some moisture will escape through the vent hose, some will remain in the condensate pan or tank. When the humidity level rises, excess humidity enters the pan, increasing the frequency of draining.

That is, if you live in a dry climate, you won’t need to drain your portable air conditioner as frequently.

Type of portable AC

Most portable air conditioners these days are partially self-evaporating, but as technology advances, more and more manufacturers are producing fully self-evaporating models.

Technically, if your portable air conditioner is fully self-evaporating, you no longer need to drain it. To eliminate the need to drain the water, these models use an extra vent hose or re-evaporate the collected water.

Check the manual to identify which type of portable ac you have. Chances you don’t need or only need to drain the water at the end of the season, like most models from Delonghi.


How frequently you use your portable ac is also a critical factor. If you keep your portable ac running all day long, it will collect far more water than if you only run it for one or two hours per day.

Daily activity

It is frequently overlooked, but your daily activities can also influence the frequency. If you move your device to a kitchen or a bathroom, it will likely fill up faster because showering and cooking can add moisture to the air.

Size of the condensate tank

The larger the tank, the longer it will take to become full. You can expect to drain water less frequently if your portable unit has a large tank.


Unless your portable ac is not cooling, you don’t need to set the temperature extremely low. This is because your machine will work harder to blow more cold air so as to achieve the target temperature.

Accordingly, it will collect more water and shorten the interval between each draining. 

How to tell how frequently should you drain a portable air conditioner?

Don’t be too concerned if you don’t know when to dump the drainage water. It has a water level sensor that will shut off the appliance automatically. Therefore, the water will not wreak havoc on your machine even if you forget to drain it in time.

To know the draining frequency, you can follow the guideline in the instruction manual. 

However, as you are aware, the outcome can vary depending on a number of factors. To determine the frequency, observe the water level in the tank or check whether the water tank indicator is on every 4 to 8 hours at first.

Because any portable ac unit will make some noise when turned on, it is easy to tell when the tank is full because the unit will stop working.

Anyway, a general rule of thumb is to drain the water every 8 hours.

How to lower the frequency of draining a portable ac?

If you don’t want to drain your portable air conditioner as frequently, you can choose another draining method. Using a drain hose or a condensate pump can save you from this chore. 

By attaching a hose to your portable ac, the drainage water can go to the floor drain constantly, making the condensate tank never fill up. 

If you want to drain the water outside the window, using a pump is a sensible idea because the water will not need to rely on gravity to move.

Another way to lower the frequency is to purchase a fully self-evaporating model. It could be costly upfront but is much more convenient. 

Wrapping up 

When it comes to how often you should drain a portable air conditioner, humidity, usage, model, daily activity, setting, and tank size all play a role.

As a result, the frequency your friend’s machine has may not apply to you. To know the frequency, you need to do your research, like checking information on the instruction manual and recording the time when your tank is full.

If you don’t bother to drain your portable ac, you can purchase a fully self-evaporating model or use a hose or condensate pump to drain the water.

At last, draining the water from your portable ac every 8 hours is always good advice to follow.

About The Author

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Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested dozens of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.

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