[muawiyah]

Best bet for the portable units is for single-room "dryout" in climates where the need is limited to a month or less.

That way you can, at least, sleep at night.

[Sherman Logan]

I agree that they have such uses, although even for this purpose most of them burn a whole lot more juice. I would strongly suggest looking for a unit that has an Auto setting where the exhaust fan shuts off when the compressor shuts off. They would still burn more electricity than a window unit, but should be more efficient than those without such a feature.