A portable air conditioner can provide relief from the heat when no other form of air conditioning is present. Portables can also provide a boost to your home’s existing air conditioning by cooling rooms that are chronically too hot, and by selectively cooling individual rooms to save energy through reduced use of the main system. Portable air conditioners are also ideal in apartments, condos, and neighborhoods where property owners or homeowners’ associations prohibit using window air conditioners. But choosing a portable air conditioner is harder than selecting a window unit. Because portables do not cool in exactly the same way as window air conditioners, they need to be properly matched to the space that needs to be cooled. This booklet explains how to evaluate the features of a portable air conditioner, choose the best-designed unit for your situation, resolve the correct BTU (cooling) capacity, install your unit for maximum effectiveness and the lowest energy use, and perform simple maintenance tasks that can prolong the life of your portable air conditioner. In addition, this booklet details situations in which portable air conditioners may in fact work better than window units, and also points out those places where a portable air conditioner may not be suitable. Not all salespeople who work at appliance stores are familiar enough with portable air conditioners to adequately give an explanation for the advantages and disadvantages of different makes and models, and neither do manufacturers at all times provide enough information to help you make a choice. This booklet can provide the information you wish to have to make an informed purchase, allowing you to make a choice a portable air conditioner that will keep you cool whilst the use of as little energy as conceivable.