(Re-running this 2023 article for my newer readers as I just broke out my unit yesterday to deal with the impinging summer heat in my office. We’re also down to 13% humidity so its making a dent! – Dan. D.)
In a recent group I overheard a couple of people discussing the “personal cooling units” they had seen on TV. One of them is camping in town while mountain biking and his van gets hot at night. I was pretty sure I knew what tech was being sold for $40 (that was the 2023 price, now they’re down to $30 – ed.) but I’d get one to check out and report on it here.
The local Wal-Mart had them in stock, the Artic Air 2.0 and online it is correctly categorized in Evaporative Coolers, not Air Conditioners.
tldr; it’s a small swamp cooler
The Tech
If you’re unfamiliar with evaporative cooling, it a method by which to absorb heat through the phase change of a liquid. Simply: liquid water evaporates into the air, taking heat as it goes. It’s why your bath towel is dry the next morning; you just don’t realize it was also making cool air while hanging up.
If you’ve ever seen the giant 48” on an edge cubes atop mobile homes and some houses in the southwestern USA, those are giant evaporative coolers. In dry climates they work very well while the power required is negligible compared to the compressor in an air conditioner. In fact this phenomena happens all the time when water is exposed to the air but add a larger surface area plus a fan to move things along and you get a larger output.
Anyway, back to the arctic: the effort to bring this thing online was about 5 minutes; soak the paper wick in water, fill the reservoir tank, plug in the supplied USB-C power adapter and press some mode buttons. The air felt cool so I took some measurements.
Raw Data
Ambient air temp: 73°F
Humidity: 12% (low!)Fiddling with placing the thermocouple for the lowest reading I measured:
Exit Air Temperature Temp Change USB Current at 5V
Max fan speed: 58°F 15°F 1 amp
Low fan speed: 51°F 22°F ½ amp
Conclusions
Do the higher fan settings create more cold air faster? Yes but not notably because the paper wick only moves new water to evaporate on a curve of decreasing gains. So 2x the fan speed does not equal 2x the cold air volume. Does it save energy? Well, define "save." It is nothing like the marketing hype from the manufacturer makes it sound. This is no replacement for a window air conditioner. But since it runs on 5W of USB power you basically get some cool air for free. Plus fancy LED colors and fan noise if that matters to you. Should I buy one? Sure, if you are camping this summer in the hot sun of the Southwest. On medium speed and with the LEDs off I'd let it run all night while I was asleep to buy a few degree decrease in the inside air temperature of my van/tent/travel trailer. Plus it increases the humidity in the air which you may enjoy – especially in dry locales like AZ, NM and CO.
A stone will be worn away by the creeping of ants. – Tamil proverb #1892