What Portable Air Conditioners Do Not Need to be Drained?

As the summer approaches and people look to upgrade cooling equipment, the question arises about what portable air conditioners do not need to be drained regularly?

While most regular portable units require a water catchment tank to be drained periodically due to the creation of a lot of condensation inside the unit, there are some that deal with that condensate differently.

Certain select brands include models that possess advanced technology that automatically removes internal moisture before it condenses.

portable air conditioner no drainThis means there is no need to drain the water or set up a hose for continuous drainage.

These units are referred to as fully self evaporating portable air conditioners, because they re-evaporate any condensate and exhaust it out through the vent hose to the outside..

Portable Air Conditioner Draining

For most AC models, frequent draining is required. The frequency depends on the level of humidity in the air.

The higher the humidity, the more moisture is extracted from the air by the AC unit. This moisture subsequently condenses on the cooling coils inside the unit, dripping down into a tank near the base of the unit.

Some portable air conditioner brands, such as Whynter, Edgestar, Avallon and Koldfront include models that make use of a condensation exhaust system to expel the water vapor that is collected during the dehumidifying/cooling process.

The vent hose is the way out for the hot, moist exhaust air that is generated by the unit during normal operation.

Do Portable Air Conditioners Require an Exhaust Hose?

Yes, an exhaust hose is required to operate all portable air conditioners. This is to allow the hot moist air produced by the unit to be exhausted to the outside.

If you do not connect a hose from a portable AC to a window or other suitable outlet, the unit will simply pump that hot, moist air back into the room, creating a net heating effect!

This is why air conditioners are vented!

While it is possible to purchase what is often referred to as a vent-free air conditioner to make your room more comfortable, these units are really evaporative air coolers and do not function in the same way as air conditioners.

How Does a Self-Evaporating Portable AC Work?

This type of portable air conditioner (such as the one pictured right) extracts moisture from the air just like any other, but instead of allowing the condensate to form and drip inside the unit, the moisture is re-evaporated and expelled to the outside via its vent hose.

Self evaporating portable air conditioners evaporate water that accumulates inside the unit using patented self-evaporative mechanisms unique to each brand.

These air conditioners can still allow water to be stored in a tank. Such as when the unit is being used in dehumidifier mode, where much more moisture is extracted from the air than can be reasonably re-evaporated and exhausted outside.

Are Window ACs Equipped with a Drain?

Modern window air conditioner units produce condensation inside the unit like any other AC. That condensate forms large droplets that drip to the bottom of the unit. The collected water drains out through a small hose located on the outward-facing side of the unit.

In Older window AC units, the fan sling distributes the water and throws it against the condenser, re-evaporating some of it to escape to the outside, while the remainder drips out through a hole on the outside of the unit.

Are Portable ACs Economical?

For most portable AC models, they are less efficient and therefore less economical than other forms of air conditioning appliance, such as window units, package terminal (PTAC) units or ductless mini-split AC installations.

The energy efficiency (SEER) score of most portable air conditioners is generally lower than that of other types.

If your home does not have central air, you can't afford to install ductless mini-split AC or the installation of window units is not permitted in your building, a portable unit in one room may be your only shot at keeping cool during the hottest summer days.

Are There Portable ACs that Do Not Require Venting?

A portable air conditioner can't be used without a vent. It can be turned on and it will run as normal, but it will not lower the room's temperature.

Even if the AC unit is placed in a room without windows, there are many ways to vent it.

While it may not necessarily be so easy to vent a portable conditioner without a window, it can be achieved through an external wall vent, or through a drop ceiling duct.


If you have been regularly emptying the tank on your old portable air conditioning unit through the summer and you're ready to get a new one that you don't need to empty, a self evaporating portable air conditioner is the answer.

These units cost a little more than the regular variety of AC. However, the extra cost works out to be good value when you consider the time saved not having to complete this labor intense chore every week or so.

Posted: March 11, 2022

[Back to Top]