I guess this attitude comes largely from all the electronics in our culture, loaded with circuit boards that seem to function by magic, and are cheaper to replace than to repair. Ok, my little rant is not really the subject of this article, but it does relate because I want people to understand that ventilating a portable air conditioner is not rocket science and should not be intimidating.
Air conditioners have been around a while, and they have really transformed our indoor spaces to havens of comfort. But like my kids, many folks have no clue how they work. One thing that is vital to all true 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 what we are trying to do is create a temperature difference between inside and out.
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.
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 improved the seal and secure the adapter in place. Lock adapters are available if one needs to lock the 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 manufacturures generally do not recommend extending the hose more than ten feet. These kits includes a 9′ exhaust hose that will fit many units. The panel has only one connection. If one wishes a dual hose setup, one would need to use two tile kits. Some portable air conditioners, such as the EdgeStar ServerCool, 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 kit, solutions can be found for most rooms, resulting in years of comfort without further issues.