We bought them to try in our little hobby room (7' x 11'), if standing directly in front within 3 or 4' they do work, but the infomercial states "they'll run 8 hours on a tank of water" it's actually maybe 2, if not running they won't last 8 hours before all the water has evaporated.
Save your money, YES we got what we paid for!!!
Of course: I can't speak for the quality of these things...
But do you think that (if they work...), they could help keep us cooler?
For the money: it would almost be worth some experimentation!
Under what conditions? Keep you cooler when?
Are you thinking inside an air conditioned RV, both running together? Or are you thinking to cool you in place of an A/C? Or are you asking to cool a space that isn’t an RV? In my opinion the question needs to be more specific for answer to be meaningful.
They are known as swamp coolers. The large sizes help in very dry areas but require near drought condition dryness. We tried them many years ago in warehouse here in Florida. Too high ambient humidity to be effective. They also require frequent cleaning. The whole premise is evaporative cooling effect from change of state from liquid to gas, essentially lick you finger and blow on it and it will feel cool.
Cooling is only a portion of air conditioning, moisture removal is another. I can leave Vegas at 82 in summer and walking into it during a normal summer afternoon feels great.
Bob, Swamp coolers work great if you have very dry air, like the desert or dry mountain areas. you keep the humidity down by usually bringing in outside air. If used correctly the are very comfortable but when the humidity rises so does there effectiveness. I can't see that the ones in your post would do much but I could be wrong.
This post is opinion based on experience.
2015 Hurricane 27K
2013 Sea Ray 220SD