How to Vent a Portable Air Conditioner with No Window

If you want to know how to vent a portable air conditioner without a window, you may be surprised to learn there are actually several other ways to do this.

A portable air conditioner can be operated in a windowless room if necessary using alternative outlets to connect the exhaust hose to.

We shall see how this can be done when there is no window available for connecting the vent hose from a portable air conditioner to.

Why a Portable AC Unit Must Be Vented

portable ac no windowAll portable air conditioners must be used with its exhaust vent or vents connected to carry the hot air out of the room being cooled.

If the vent hose in not connected from the AC to a suitable outlet, the hot air produced by the refrigeration process will not be exhausted outside of the building. This will result in heat building up in the room where the AC is located and a net temperature increase occurring.

This is obviously not the outcome expected when you run an AC device!

Since more hot air gets vented into the room from the rear of the unit than cold air is pumped out the front, the temperature in the room will rise.

Most AC manufacturers include a flexible hose and window fixing kit to enable efficient venting of portable units. However, when there is no window available, there are other options for venting.

When Venting a Portable AC is Not Possible

There may be times when a portable AC in a windowless room cannot gain access to the outside. This would generally happen where a room is deep within a large building without access to a potential exterior outlet.

One solution to this problem would be to use what is often called a ventless portable air conditioner (really an evaporative cooler or swamp cooler), while keeping a door open to allow air to circulate. In such a case, if there is little or no airflow, a dehumidifier would be needed to combat the raised humidity produced by the swamp cooler.

Five Alternative Portable AC Venting Options

There are more than just one way to vent a portable AC unit.

Here are no less than five different ways to vent a portable AC without a window. It can turn out to be a little more difficult, but it's certainly possible.

Door Vent

Although windowless rooms exist, you don't find too many doorless ones!

Every room has at least one door, so you can vent your portable air conditioner through it. Venting a regular or self evaporating portable conditioner through the door can be the easiest way, although there are one or two limitations to this solution.

It is crucial that you know where those doors lead. If they lead to a hallway or another area inside the house, you may have difficulty reducing the temperature in your windowless room.

If the room has access to a balcony door, the air conditioner can be vented through that to the outside.

Sliding balcony doors open to the outside. Installing a sliding doors seal is very simple and will give you the temperature difference that will make your portable AC unit just as effective as it would be if it were vented through a window.

Installation of the portable AC Vent 6 feet for ordinary doors can be difficult. Installation of the ventilation kit for sliding casement doors is very simple.

These kits are made to fit sliding doors up to 150 inches in size and measure 6-8 inches wide. Simply mount the kit to the balcony door, attach the vent hose, then run the portable air conditioner as normal.

Wall Vent

Every room has walls, but is at least one of those walls an outside wall?

Ventilation through walls is possible for portable air conditioners that can't be vented via the window, as long as there is an outside wall where the vent would carry the hot exhaust air out of the building.

If there is not already a wall vent for a fan, you must make a hole in your wall if you want to put an AC unit there.

If you are a handyman and have a power tool, you can drill holes in the wall. The hole should be equal in diameter to the hose that will vent the portable AC.

This method is more often used for single-hose portable conditioners. Portable air conditioners with dual-hoses are more efficient, but people don't like drilling too many holes in walls.

Clothes Dryer Vent

There are no dimension differences between a clothes dryer vent or a portable AC vent.

If you are venting a dryer, you can also use the same hole for venting a portable air conditioner. Just remember to switch hoses depending on which appliance you are using at any given time.

Ceiling Venting

If you don't have any windows, but you have a dropped ceiling, you could vent a portable air conditioning unit through the ceiling.

Ceiling venting is popular in offices. Many offices have a dropped ceiling that are suitable for adding ductwork to in order to create an exhaust vent pipe.

Drop ceiling venting kits can be obtained and are a great way to install the venting line. These kits can extend your hose length up to 10 ft and are universal.

Chimney Venting

Chimney venting without a window is a less popular way to vent a portable conditioner. It does require some additional construction work to make it viable and safe.

First, you should have a chimney that is not being used for a working fireplace.

It can be tricky to insert a long flue up through a chimney and fix it at the top. It is best to speak to a professional to verify all safety concerns.


It's not always very easy to vent a portable conditioner without a window, but it is possible.

If the room in question has a sliding balcony door, an external wall that can be drilled through or already has a suitable dryer or fan vent, a drop ceiling or a chimney, you're good to go!