How To Vent A Portable Air Conditioner

Most portable air conditioners have come with a handy, easy-to-install window vent kit. You can get creative when thinking of venting options, and you can vent through the floor, ceiling, a chimney, and even vent into another room. The primary goal of venting is to get the hot air from the compressor out of the room you are trying to cool.

One thing that is vital to portable air conditioning systems is ventilation. Ventilation means air circulation between the space being conditioned and somewhere outside that space. Air needs to move back and forth, but in a controlled manner, since we are trying to create a temperature difference between inside and out. This guide will teach how to vent a portable air conditioner.

Portable air conditioners function like most other air conditioners. What sets them apart is the fact that the entire unit is located completely within the room they are conditioning. In contrast, central units and mini-split systems have components located both inside and outside the building, whereas wall and window units sit “on the fence,” half in and half out of the room.

So the problem with portable air conditioners is how to create the vital ventilation path between the unit and outside the room. They all use one or two hoses to accomplish this. Typically, the hose(s) is (are) connected to a window vent kit.

Venting Portable Air Conditioners with Window Vent Kit

The window vent kit is basically a flat piece of fairly rigid foam or plastic with one or two holes and connection ports. The kit is adjustable to fit in a vertical or horizontal sliding window. One simply opens the window, adjusts the kit to fit window dimensions, and pulls the window into contact with the kit.

Duct tape may be desired to improve the seal and secure the adapter in place. Lock adapters are available if one needs to lock the window.

Window vent kits are quite nice because they are included in the price of the unit and require no changes to the structure of the building. However, since the hose(s) supplied with portable air conditioners are generally only about five feet long, the unit must be placed near the window.

A fairly frequent question from people considering a portable air conditioner is what to do when the room contains no suitable window. There are solutions to this issue. One is ventilating to the attic.

If the room has a standard drop-tile ceiling, kits are available for a little over $100, which simply replace a 2′ x 2′ or 2′ x 4′ tile with an insulated steel panel that has a hose connection in its center. These are often used in computer server rooms, which commonly have no windows.

Portable air conditioner manufacturers generally do not recommend extending the hose more than ten feet. These kits include a 9′ exhaust hose that will fit many units. The panel has only one connection. If one wishes for a dual hose setup, one would need to use two tile kits. Some portable air conditioners can be used in either single or dual hose configuration.

One should consider the ambient humidity when considering ventilation to the attic. Portable air conditioners pull a lot of moisture out of the air, which collects as condensate. Many modern units re-evaporate the condensation and blow it out of the room with the exhaust air. Tile ceilings have been known to get wet over time, leading to discoloration, sagging, and even collapse, especially in areas of high humidity. Large attics with good ventilation are less likely to have such problems.

Another alternative for either ceiling or through wall venting is a dryer vent, installed just as they would be for a dryer. Two can be installed side by side for dual hose units. This is quite an elegant solution despite the fact that one must put a hole in the wall. It creates a ventilation portal that is very inconspicuous, permanent, and easy to reach and use. Also, one is not restricted to placing the unit near a window but can put the dryer vent pretty much where desired.

With a little thought and research, other solutions can be discovered. For example, people with casement-type windows have constructed plexiglass panes that fit into the casement window frame with the window open and cut a hole in the plexiglass for the hose to connect. Basically, any communication to the outside can work, as long as it is reasonably well sealed and stable.

I guess the point of this discussion is to inform readers that sliding windows are not required to use a portable air conditioner. While it may require a little more work and cost than the window vent kit, venting portable air conditioners options can be found for most rooms, resulting in years of comfort without further issues.

Mas Broto

Written by: Mas Broto

Mas Broto is a small business owner with 30 years experience in the real estate industry. He is the founder and editor of, the most comprehensive free home improvement website on the planet!