The statement above is the greatest misconception we saw regarding portable air conditioners and it results in a lot of 1-star ratings: people don't realize that, even though a portable air conditioner is not a window air conditioner, you MUST have a window to use a portable air conditioner (although, a sliding door or any other way of venting the exhaust to the outside will do as well). We wanted to make that clear early on, so that, if you don't have the option of venting your portable air conditioner to the outside, you can head on over to our report on fans instead, to find the one that will keep you the coolest. When considering how to cool a home, there are two main options: central air conditioners (which cool the whole house from a central location) and smaller window or through-the-wall air conditioners that cool down individual rooms. We cover both of those types of air conditioners in their own reports, but there's also a third alternative -- a portable air conditioner.

These are similar in scope and cooling capacity to a window air conditioner, but their more modest venting requirements make them easier to install -- especially in rooms where installing a window unit is either undesirable or impossible, such as apartment units where they may be prohibited. The best portable air conditioners can be set up quickly by just one person and can be moved around to cool a different room as needed, although they're still heavy in spite of having wheels. A portable air conditioner doesn't commandeer a large section of the window (like a window air conditioner does), but a portable AC still needs access to outside air. Each portable unit comes with a window kit, which mounts one or two hoses to a small panel that's installed in a window. Some experts prefer the dual-hose style because it provides slightly better performance. says that, while that's true in theory, in practice the difference is actually very slight. In our research, we found that single-hose models often rate as well or better than many dual-hose portable air conditioners, and typically cost less.

All air conditioners, including portable air conditioners, pull excess moisture from the air. This is stored in a water tank that must be periodically emptied (machines will shut down when the tank is full) or drained continually through a hose running outside. Portable air conditioners with a self-evaporative system minimize the need for emptying, though under more humid conditions, the water tank may still need to be emptied occasionally, and more frequently if the humidity is exceptionally high. Some portable air conditioners have dehumidifying functions that pull excess moisture from the air without cooling it. If you are primarily interested in that, we cover dedicated dehumidifiers in their own report. In doing the research for this report, we quickly found that expert reviews of portable air conditioners offer only half-hearted recommendations, and user reviews aren't much rosier. Like window air conditioners and central air conditioners, the cooling capacity of a portable air conditioner is measured in British Thermal Units, or BTUs.

, portable air conditioners aren't held to the same rating standards as window units or central air systems, so there's often a disconnect between their claimed BTU rating and the size of room a portable air conditioner can satisfactorily cool. how to buy new ac unitMcCabe notes that even different models with the same BTU rating will vary in their actual cooling capacity.ac unit working but no air That means that the disparity between the BTU ratings of window and portable air conditioners renders traditional sizing guidelines somewhat moot. how much does it cost to have your ac unit servicedInstead, where a 6,000 BTU window air conditioner might be great for a small bedroom, testing shows that you may need to turn to a 10,000 BTU or better portable model to get the same degree of cooling.