3 Ways How To Drain Portable Air Conditioner: Do You Even Need To? (2024)

“Do portable air conditioners need to be drained?”

Yes. All portable AC units accumulate moisture and need to be drained regularly. AC units both cool and reduce humidity. The gathered water needs to be drained. This means either manual drainage (#1 way) or automatic drainage (#2 and #3 ways).

How to drain a portable air conditioner?

We are going to look at 3 ways how to drain a portable AC unit, including the so-called ‘no drain portable air conditioner’ way. All brands of portable units – including Toshiba, LG, DeLonghi, Black and Decker, Insignia, Haier, Midea – are drained in one of these ways.

Let’s first address one of the most frequent questions our readers have about drainage:

“Why is my portable air conditioner producing so much water?”

If you use a portable AC unit in a room with high relative humidity levels, you will see that these units produce quite a lot of water. In ideal conditions, these efficient portable air conditioners produce more than 4 pints of water per hour. That’s about 100 pints or 15 gallons per day.

Now, all that water has to go somewhere. It certainly doesn’t stay in your portable air conditioner. That’s why all portable AC units need to be drained quite frequently (we will also talk about how frequently you have to drain a portable AC unit). Luckily, you don’t always have to do it by hand (emptying the bucket located at the bottom of portable units).

Let’s look at 3 drainage systems portable air conditioners use:

How To Drain A Portable AC Unit?

In the summer, indoor humidity levels can rise above the ideal 30% to 50%. If you live in areas with high humidity, it’s not uncommon to see indoor moisture levels rise to 70%, 80%, or even 90%.

The primary function of air conditioning is to reduce the temperature. Secondarily, however, portable air conditioners work as dehumidifiers as well. They reduce humidity levels as we have written in this post about if all AC units remove humidity.

Example: Let’s say you put a 10,000 BTU Toshiba air conditioner in a 300 sq ft room with 85°F temperature and 70% humidity. After you run it for an hour, the temperature is reduced to 75°F, and humidity is reduced to 50%.

We know that the portable AC unit expelled the hot air through a hose to generate 10°F temperature reduction. The unit also reduced the humidity levels by 20%. Where did all that water go? Is it in the bucket? Did it go through the hose? Where was the accumulated water drained?

To see how portable air conditioners dispose of water, let’s look at these 3 operating methods of how portable AC units are drained:

1. Portable AC Unit Drained Via Condensate Tank (Manual Drainage)

Older portable units collect the water in the built-in condensate tank. Water is condensed on the cold evaporator coils and drips into this draining pan.

There are two ways how to empty this condensate tank:

1. You have to remove the tank. Some old portable AC units like LG and DeLonghi have a detachable condensate tank. You have to manually remove the tank and empty it when it gets full. Newer units will have a light on the control display that turns on when the tank is full.
2. You have to pick up the unit (not-removable tank). With built-in tanks, you will have a small hole at the back of a portable AC unit. That hole is sealed when AC is running. When you want to drain such a portable AC, you have to pick up the whole unit (portable ACs can weigh 40 lbs or more), carry it to the bathroom, and empty the tank there.

Of course, this way of portable air conditioner drainage is the worst. Nobody really likes to manually drain a portable AC unit. That’s why newer air conditioners have a more automatic way of how to drain them:

2. Automatic Drainage Via Hose (‘No Drain Portable Air Conditioners’)

The best modern portable AC units don’t have to be manually drained. The ‘no drain portable air conditioners’ are automatically drained via the exhaust hose. As we have written before, there are no portable air conditioners without a hose (that would go against the 2nd Law of Thermodynamics).

Despite the ‘no drain portable AC’ name, these units have to be drained. However, you don’t have to do anything to drain them yourself.

The accumulated moisture is basically vaporized and expelled via the exhaust hose. If you measure the humidity levels of exhaust airflow in older units, you will see that you are expelling dry air (below 30% humidity). If you measure the humidity levels of these newer units, however, you will see that they expel hot and humid air (above 50% humidity).

These no drain portable air conditioners sound to good to be true. That’s why most future owners have two questions about them, namely:

1. Do no drain portable air conditioners cost more?
2. Are no drain portable units less energy efficient?

Despite being new and more user-friendly as far as drainage goes, these units don’t cost more. It’s just the case of new technology replacing the older technology. You might see a $10-$50 increase in price tags of no drain portable air conditioners but that’s a pretty insignificant price increase given how easier these units are to drain.

You don’t have to be concerned about energy efficiency. Yes, these units do use a bit of electricity to vaporize the water, but due to newer technologies in them (namely inverter compressors), they are more energy-efficient than older units with condensation tanks.

Example: A 10,000 BTU older version of LG portable AC unit will have an EER rating of 9 (Energy Efficiency rating). The newer version of a 10,000 BTU LG portable AC unit will have an EER rating of 10 due to the use of more efficient inverter compressor technology.

3. Drainage Via Drain Hose (With Or Without A Condensation Pump)

A limited number of portable air conditioners are drained via a drain hose. This is basically a hose that continuously drains the built-in condensation tank outdoors. You have a constant flow (drip) of water out of the portable AC unit. Consequently, you don’t have to do anything manually to drain them like with older units.

There are two kinds of drain hose portable air conditioners:

1. Gravity units (without the pump). With these units, you just channel a drain hose out of the window. The key here is to put the lower end of the outdoor end of the hose lower than the indoor condensation tank. Due to gravity, the condensed water will flow continuously without any help from a pump.
2. Condensation pump units. These units are placed in lower parts of a house – basem*nt, lower floors, and so on – where you can’t channel the hose in much the same way as with gravity units. That means that the outer end of the hose is elevated above the indoor condensation tank. To bridge this difference in height, portable air conditioners use a condensation pump. This pump sucks the accumulated water out of the condensation tank located in the portable air conditioner and pumps it outdoor against gravity. Pumps, however, use a bit of electricity as well and lower the overall energy efficiency of portable AC units with condensation pumps compared to gravity pump-less units.

In general, the drain hose is preferable to manually emptying the tank. Nonetheless, drainage via an exhaust hose (#2) is still a better way to drain a portable air conditioner than with a drain hose.

How Often Should A Portable Air Conditioner Be Drained?

If you have drainage via an exhaust hose (#2) or via drain hose (#3), you don’t have to manually drain the portable air conditioner at all. It’s done automatically for you.

With older units, however, you will have to either empty the detachable condensation tank or lift the whole unit up and empty the condensation tank in the bathroom.

How often should you drain these portable AC units?

Simple. When the tank is full of water, you have to empty it. Now, older models don’t tell you when the tank is full. Newer models do have a signal light that tells you when you have to empty the bucket.

With older units, the frequency of emptying the tank varies quite a bit. This depends on how much humidity you have in the house, what size unit you have (BTU capacity), portable AC condensation tank size, if you run a portable air conditioner continuously, and so on.

In high humidity areas, homeowners will have to drain the portable AC every few hours (2 to 8 hours, in general). In other areas, you have to drain the unit once per day or every few days.

Exactly how often your portable AC unit has to be drained is very hard to determine theoretically. The best way is just to see practically how quickly the condensation tank fills up.

Bottom Line

All portable AC units have to drained, even no drain portable air conditioners. The real question is if you have to do it manually or is it done automatically. 3 ways of portable AC unit drainage systems include:

1. Via condensation tank. These older units still have to be drained manually every few hours, once a day, or every few days (depending on the humidity levels).
2. Via exhaust hose. This is an automatic drainage system that is preferred by most people.
3. Via drain hose. This is also an automatic drainage system that continuously drains the portable AC unit.

All in all, if you get a newer unit with an exhaust hose or drain hose drainage, you don’t really have to worry about how to drain a portable air conditioner nor how often portable AC units should be drained. Everything is done automatically.

Hopefully, you now have a better insight into how these portable units are drained. If you have any questions, you can use the comments below and we’ll try to help you out with those.

Thank you.