With temperatures rising outside a seemingly easy fix is a portable air conditioner. It draws in warm air and exhausts it outside through a hose that connects to your window.
Consumer Reports tested eight - from brands including Honeywell, Haier and Frigidaire. Prices range from 250 to more than 500 dollars.
Consumer Reports used a special chamber to test their cooling power. The temperature outside is kept at 90 degrees, the humidity at 70 percent. Inside, each air conditioner is set to 75 degrees.
Strings of thermocouples record temperatures throughout the room. The results were disappointing.
As Bob Markovich of Consumer Reports explained, "None of these units, not even the biggest ones, could get our test chamber below 80 degrees even after an hour and forty minutes."
That was true even of the most expensive unit tested - a 550-dollar Honeywell - which promises it "cools up to 550 square feet." It struggled to cool the test chamber, which is half that size.
"Window air conditioners are much more effective and they tend to cost less," said Markovich.
Consumer Reports found several window air conditioners to recommend. Top-rated for larger rooms, the 350-dollar LG. (LG LW1214ER)
For medium-sized rooms, the LG for 240 dollars.
And for smaller rooms, the 210-dollar GE is a Consumer Reports Best Buy. (GE AEM05LS)
Consumer Reports says be sure to pick the right size air conditioner for your space. If the unit is too small, your room won't get cool enough. But an air conditioner that's too big may make it feel cold and clammy.
A 5000 to 6000 BTU air conditioner will cool a small space - about 100 to 300 square feet. For rooms 250 to 400 square feet choose a unit with about 7000 to 8000 BTUs. And for larger areas - about 350 to 650 square feet - you'll want a unit with about 9800 to 12,500 BTUs.
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