How does a stand-alone inside air-conditioner work

Short version: a window AC sized swamp cooler can provide a small amount of real cooling under ideal conditions. If at all possible, just use a proper window AC.

When I was a student I lived in a one room apartment, and we were not allowed to have air conditioners, so I had a free standing swamp cooler. It was about the size of a small window AC, and consisted of a fan, water reservoir, pump, and evaporation substrate. The evaporative material was either wood shavings or foam (I replaced it a few times), and was about half an inch thick, and maybe two square feet. So much larger than the little desktop units.

It worked, but just barely. Measuring the input and output temperatures of the air, it was less than a 5F temperature drop. It was real, and measurable, but not much. I kept it in a window, so it might be bringing in 84F outside air, and dropping it to 81F before blowing it around the room. This is in a very dry climate, so ideal conditions. The small temperature drop was worth the effort of filling it with water once or twice per day, over just using a window fan.

The swamp cooler is so simple, and refuses to break, so in the many years since, I’ve occasionally used it in my house in the winter as a humidifier. The fan is larger than a typical desktop humidifier, so in exchange for being loud, it can put more moisture into the air than my other options. Because of that, I only bring it out when the dryness is causing skin problems.

Right. One of those tiny ones, where you use ice can make you feel cooler without raising the humidity so much it is pointless- but that is just enough to cool one person.

If you have a tube or something to vent it out- yes.

More than a small amount if the outside has low humidity. They work fine in the desert.

Yes, large ones work well. Have you seen the size of the ones people use for whole house cooling? Just picking the first one I found, this one designed to cool 1600 square feet is a box 34" \times 34" \times 46" and weighs 170 pounds, before adding water.

That same search showed several portable models, which probably also work fine, but they’re not desktop sized, and are not cheap. The ones with good reviews are floor standing, and start around $200.

https://www.lowes.com/pd/Essick-Air-1600-sq-ft-Window-Evaporative-Cooler-4700-CFM/4741315

Yep, the larger the more they cool. What we do is we have a larger portable by the back screen door- when it gets cooler outside we open the sliding glass door and turn on the swamp cooler- with the very dry air outside it cools quite well. But it is about 4 feet tall,

ISTM the intended use case for the not very effective mini swamp cooler is for someone in an office cube farm or such who either prefers it cooler than TBTB, happens to be in a warm spot in the building, or are near a window absorbing solar heat. Regardless of cause, their interest is micro, not macro.

It’s all about creating a micro-climate a couple feet across that’s incrementally better than doing nothing. While employing something you can sit on your desk, plug into your power strip, and not get yelled at for having.

It’s the summer equivalent of that thin cardigan you keep in your lower left desk drawer for use in winter.

It is NOT an air-conditioner. They call it an “AC”, which is double-speak for “air cooler”. It’s really a mini-humidifier.

Maybe, but even in that optimal use case, and with optimal very low ambient humidity, it’s still only slightly more effective than a fan of equivalent power, with the added fuss of having to refill the reservoir frequently. And if you’re willing to refresh water in a cooling device, it’d be much more effective to just have a fan, and then have a damp towel draped around your neck.

Yeah. It’s a cheap product in search of a barely plausible use case.

My brother points out that the world is increasingly filled with consumer products which are built to be sold, not to be used. IOW optimized for cost and curb appeal, not for actual functionality or durability.

In his line of work he’s forever repairing or reinforcing various consumer gizmos bought by small retailers for in-store or in-restaurant use that give zero thought to durability but look great in the catalog / web page. And boy are they cheap! Such a bargain.

Well, draping a damp towel around your neck isn’t particularly conducive to an office setting where it may soak/stain your shirt. Also there’s some benefit to having a device with a slower quieter fan that provides a similar amount of cooling without also blowing the papers on your desk around or blowing on the person sitting nearby.