I don't think they're scams. They are certainly not as good as a split heat-pump AC, but they work to make a small to medium room go down from 35℃ to 25 or so,

I don't think they're scams. They are certainly not as good as a split heat-pump AC, but they work to make a small to medium room go down from 35℃ to 25 or so, which is more than enough to go from roasting to being comfortable.