This article is the archived version of a report that appeared in the August 2009 Consumer Reports magazine.
An ad for the Cool Surge portable air cooler says it "cools the air in an average-sized room up to ten degrees so you'll instantly feel cool and refreshed." It's "as easy to use as a baby's vaporizer," "uses the same energy as a 60-watt light bulb," and costs "just pennies a day to operate." Each unit sells for $298, though when we tested you could buy one and get one free—kind of. (You pay for shipping: $49 per unit.) Cool Surge can be bought online or over the phone.
The device basically works like an evaporative cooler (a.k.a. swamp cooler). It consists of the following: a reservoir into which you pour about a gallon of water and drop two of the type of reusable ice packs you'd put in a lunchbox; a mesh curtain that dips into the water and wicks it up (water can also be pumped over the curtain); and a fan to move air through the wet curtain.
As in our tests of room air conditioners, we placed a Cool Surge in a 12-by-17-foot room where we controlled conditions to simulate an 85-degree day with 57 percent relative humidity. We recorded temperature data collected from strings of sensors hanging from the room's ceiling and from the front and back of the device. We tested the unit with the pump on and off. We also tested a second sample. The Cool Surge includes a heater and a faux mini-fireplace. We didn't test those, and we didn't assess the device's safety.
The Cool Surge left us cold—but not literally: During our 4-hour test, it failed to lower the average room temperature appreciably. Even when we lowered relative humidity to create a desertlike 25 percent outdoors, it managed a mere 2 degrees of cooling.
What's more, the Cool Surge is not especially easy to use. Once its ice packs are thawed, you have to wrestle them out of a cramped space, and for occasional emptying and cleaning of the reservoir you need to roll the device (about 30 pounds when full) to a place where you can drain it.
It does use about the same energy as a 60-watt bulb and costs less than 20 cents per day, running on high, at the national average of 11.4 cents per kilowatt-hour.
Because the Cool Surge is ineffective, we've given it our Don't Buy: Performance Problem judgment. If you really want to cool a room, buy a window-mounted air conditioner. Effective ones cost as little as $140. To cool yourself (but not the room), try a $20 fan.