The introduction of a relatively new class of commercial portable air conditioners, also called portable spot coolers, has given IT managers of smaller server and telecom rooms a convenient way of solving their air-conditioning backup problems.

There are two types of portable air conditioners: air-cooled and water-cooled. Water-cooled portable air conditioners are more efficient than air-cooled ones, but they use high-pressure water lines that can leak. Therefore, like portable evaporative coolers, they are usually considered unsuitable for use with IT equipment. For the purposes of this paper, the terms "portable air conditioners" or "portable spot coolers" refer only to air-cooled systems.