Should a Portable Air Conditioner be Vented Through a Window?

There are many opinions on whether a portable air conditioner should be vented through a window and why a flexible exhaust vent hose is used for that purpose.

Let us examine this question in some more detail to discover the answer and explore other options that may be available.

It is important to know that air conditioners of any design produce both hot or cold air.

should a portable air conditioner be vented through a windowThis is due to the nature and operation of the refrigeration system that takes place inside the device.

We want the cold air to circulate in our room during summer to keep us cool and comfortable.

This time of year, hot air is definitely not desired in our homes and places of work!

Removing Hot Air

Air conditioners remove the hot air produced by their cooling equipment and pump it outside to the open air via ducting installed through walls.

This is done with all fixed AC equipment. Ducting connects the external cooling unit outside to the internal cooling unit through walls to allow the passage of air.

In the internal unit (compressor/dryer), hot air is created and moisture from the inside air is removed, drying the air. The external unit's fan draws the hot, moist air through ducting and releases it to the outside.

This is how central air units (HVAC) and mini-split AC systems cool indoors. The process of window AC units is similar, but the hot air is expelled through the window unit's outward-facing panel vents.

How Portable AC Exhausts Hot Air

Portable air conditioners work in a different way. They come with a flexible vent hose (some have dual hoses)which needs to be connected directly to an outlet to remove the hot air from any room they are cooling.

The same applies to portable self-evaporating AC units. Hot air and moisture is removed from the room via the exhaust hose.

This flexible exhaust hose is required because portability requires the ability to move the unit from room to room. The hose is connected to the external wall outlet fixed in each room the AC unit is used in.

Window Outlet or Wall Outlet

The easiest way to get the hot air out is through a window. This is because it is very easy to install a specially designed outlet vent on a window.

While some new owners may not agree with the ease of installing the window fixing kit, it is far easier than drilling through an external wall.

Sometimes a wall vent is the best option. The task is much easier if there is already an existing wall vent. If not, you will need to drill a hole in the wall.

Other Venting Options

Although a window and an external wall are the best options for venting portable air conditioners through, you can also consider other options if you do not have one or cannot drill holes in an external wall.

If the door to the balcony opens from the room, it could be used. Installation may be difficult, but professionals should be able handle the job.

A chimney, if present, is another way to vent. This is more common for older buildings.

A long flue must be installed inside your chimney to allow hot air to flow freely. A professional should do this type of work.

If you already have duct work, it's possible to either reuse it or install ducting through a drop ceiling if necessary. This is however more common in commercial buildings and offices.

When Venting is Not Possible

If you don't have a way to vent the portable AC inside a room there is an alternative.

A portable evaporative cooler (swamp cooler or ventless air conditioner) produces no hot air and therefore does not need a vent hose or venting access through a wall or window.

There are limitations to this option as swamp coolers do not work well in humid conditions. The room must have an opening window to allow for air circulation and ideally you will need to live in an area that has low average humidity.


A portable air conditioner must to be vented and using a window is recommended by AC manufacturers who generally provide a window fixing kit with each AC unit.

However, if no suitable window is available, there are other options.

You should explore all options as long there is an exit route for hot and moist air from the room to the outdoors. It is not wise to install a portable AC unit in a room that does not have venting.

Portable air conditioners must be vented outside in some way. A window is the best option and the most commonly used. But it is not the only choice.