Q&A for How to Install a Portable Air Conditioner

A standard portable air conditioner containing refrigerant gas must be vented outside a window because it draws in warm air, cools it, then releases cool air into the room and pushes the warm air back outside. At this point in time, it is not possible to find a portable air conditioner that can be used without an external venting requirement but you may be able to vent it somewhere else than through a window, depending on what your house situation is. If you did use it without venting, it would be highly ineffective and your electricity bill would be enormous as it would struggle to work efficiently. As an alternative, you could use a portable evaporative cooler which is fully self-contained and only needs a window to be open but these may be less effective at cooling and don’t work in humid environments.

If you don’t use a window or similar outdoor outlet, a portable air conditioner will run but won’t work effectively. It will try to do its cooling job but will be battling against the inability to expel the moist and warm air that keeps circulating after attempting to cool down the room’s warm air. Thus, you’d effectively be returning more warm air to the room while the air conditioner battles to cool it. As such, your electricity bill will rise steeply. Worst of all, it will not feel much better in your room or space, as the cooling effect will be ineffective. If you can find an alternative place to vent the hose through, perhaps an open door, entryway or a cat flap in a door, maybe that can work for you instead of mounting through a window.

Yes, there are portable air conditioners without exhaust, they’re known as evaporative coolers. If you live in a dry air environment, you can use a portable evaporative cooler. This doesn’t require a venting hose, just an open window. However, if you live in an area with high humidity, or your indoor areas are damp, the evaporative cooler stops being effective and it just basically pushes around hot air. If you can use an evaporative cooler, you’ll find it’s a lot cheaper to run than air-conditioners.

While it is possible to vent a portable AC into an attic, you do need to think about the consequences of dumping damp, moist air into your attic. For many houses, this isn’t the wisest of options, unless you have a roof-space built to cope with a dry/low-humidity climate that hasn’t been built/lined to stop moisture build-up (as you’ll effectively be trapping unwanted moisture in the roof space if it’s lined). This is a question that really needs an air-conditioning expert to assess the options for your particular house and attic space, to ensure you won’t be making a damp mess in the roof space.

Yes.

Use a hose clamp.

Modern ones are fairly quiet.

Yes. Follow the directions for the sliding glass door, but on a smaller scale.

Go to a hardware or home-improvement store.

Go to a hardware or home-improvement store and buy a kit that will fill in the excess space.

Replace the window. You AC unit was not designed for that type of window.