Do All Portable Air Conditioners Need to be Vented Outside?

Portable air conditioners are becoming an increasingly popular option, especially during the hot summer months. Their installation-free aspect is probably one of the main reasons why many people prefer this mobile air conditioning option. Indeed, the portability (most units have caster wheels) and relatively lightweight design enable you to enjoy the cooling benefits of a central air, through-the-wall, or window conditioning unit without moving a muscle. But, what about venting your portable air conditioning unit? Do you have to vent it outside? The short answer is YES. But, let’s look into the details you need to know. Do All Portable Air Conditioners Need to be Vented Outside?

How Air Conditioning Units Work

The reason for their existence is to cool a warm area. In doing so, they use a refrigerant (cooling agent) that uses a fan to absorb the heat from the air, cool it, and then release cool air back to the atmosphere. The heat that is created during this process, however, needs to be vented somewhere. The best option is to send it away from the room where the AC unit is installed/placed. Otherwise, it will remain in the same area you are trying to cool. It will be like having two giants clashing against each other, one canceling the effect of the other. For this reason, portable units come with an exhaust hose that helps vent out that warm air, usually through a nearby window.

The “Catch” with “Ventless Air Conditioners”

You’ve probably read about ventless air conditioners (aka swamp coolers or evaporate coolers). Although these products are marketed as air conditioners not needing to be vented outside, they are far from functioning like a regular AC. So yes, you can purchase a ventless AC unit, but you can’t expect them to pack the same punch as a typical AC model. This is because ventless air conditioning products have a very different way of refreshing you during scorching temps. In a nutshell, they do not release cool air to the room. Instead, they bring the temperature down by sucking in the hot air, moving it through wet filter pads, and releasing it into the atmosphere with some added moisture (no refrigerant used whatsoever).

So although you can run your portable air conditioning unit without venting it outside, you actually feed it recycled (hot) air. Nevertheless, if the summers in your area are warm and dry, ventless air conditioners are still a great option as they will make the overall heat-related discomfort a tad better for you.

Final notes:

• You can vent a portable air conditioner out using a dryer vent, provided the diameter of the vent hose is not greater than that of the dryer vent (usually 4”). However, this is not recommended by the manufacturer since most mobile AC units are 5-inch exhaust hoses.
• If you need to cover the exterior opening of the vent, it’s best to use a screen rather than the external part of the dryer vent (the one with the flaps). The compressor will probably have a hard time pushing those flaps to open.
• Many portable AC units feature self-evaporative technology to pull out the moisture of the air. If your climate is super humid, however, you will probably need to place a reservoir inside the unit to collect the little bit of water that will accumulate.