The weather map is a big blur of red and orange, but you probably don't need a weatherman to tell you it's hot. Before the heat waves chase you to the hardware store for an AC unit, consider these factors for choosing the best model for your home.
Window vs. Portable: Window units are the quickest and easiest solution to cooling your home. But there are some exceptions to consider. Do your windows provide a million-dollar view? Does your apartment or HOA have regulations prohibiting the use of window units? Are you a homeowner but not looking to remodel or draw attention to a wall unit? If you answered yes to any of these questions, a portable AC may be the less invasive, less permanent option.
AC Geometry: Now's the time to pull out that handy measuring tape. You'll need to know both the size of the space you want to cool and the size of your windows. It's very important that you buy an AC unit appropriate for your space; getting one that's too powerful or too weak can actually waste energy and compromise the effectiveness of the unit. (Check here to see what kind of capacity you need.) Generally, AC units are available for most window sizes, but for a very large space with small windows you may need multiple units. If the appropriate windows aren't available, you may need to supplement with a portable model, which only needs a window for the water exhaust tube.
Storage and Installation: Portable AC units are lighter than window or wall units and are typically set on casters. This makes them easier to move from room to room and small enough for storage in the off-season. Portable AC units are especially appealing in milder climates where summers are short and you may often want to forego air conditioning and open the windows instead. However, disposing water from these units can be fussy--requiring a drainage tube to the outdoors or frequent emptying of a drainage bucket.
Window and wall units are typically heavy and more difficult to install, requiring at least two sets of hands. They're also bulky to store during cold months. However, once installed, they are near permanent and take up no floor space, making them the better option for long-term use.
Energy Efficiency: Owners of portable ACs complain nearly universally that they aren't very effective. A portable model may cool a room by a few degrees, they say, but it won't cool as effectively as a window unit. To cool any given room, a portable AC requires a higher BTU rating than a window unit.
Noise: Both basic window units and portable air conditioners can be very noisy, but reviewers seem to find more quiet window and wall models than portable ACs. Window units that are easier on your ears may not be equally kind to your wallet. But bear in mind that a quiet window AC may still be less expensive than a portable one.
Price: Despite the fact that they aren't as efficient, portable AC units typically cost more. The smaller the room, the more you'll pay for a portable model compared to a window unit. As the capacity of the AC (measured in BTUs) goes up, portable air conditioner pricing becomes more competitive. In general, portable units also come with more standard features like timers and remotes.