Two window air conditioners that look identical can vary significantly in cooling power. Just look at our top pick: The Midea U-Shaped AC has models rated at 8,000, 10,000 and 12,000 BTUs.

For both window and portable air conditioners, prices are all across the board. It depends quite a bit on the particular brand you choose, the BTU rating, and the square footage it's good for.

Clean your window AC unit about every 60 days if it's in continuous use. If the unit doesn't serve as your heater, store it in the off season so dirt doesn't accumulate.

Window AC Window air conditioner units can be fairly inexpensive. They generally cost around $100 for a small single-room unit. More powerful units capable of cooling large spaces can cost $300 to ...