You definitely have to use them under the right conditions. I was skeptical at first if they would be worth anything in Seattle, but it really looks like a game of turning it on at the right time.
If it's humid or already cool, just use it as a fan. But really anything above 80F and below 60% humidity should have some effect
It should be 85F and 35% tomorrow, so that'll be its first real test. If it even knocks 5F off of my living room, that would be a welcome change.
@Alex In the right conditions (~27c, 30% or so humidity), i get air coming out 7c lower, which I can direct to blow on myself to be pretty comfortable, despite the cement block oven I live in (Thermal mass is NOT good in heatwaves, let me tell you.)
I probably get to use it 20% o the time, get to use the fan part of it another 20%. The rest of the time it really isn't as good as my air conditioner (which I set to 26c/79f)
It's possible that a larger, more powerful unit might help, but mostly it's a very nibbles at the margins kind of device
@Njord One neat side-effect I'm learning testing it out today is that it seems to make my air conditioner more efficient.
I have a floor unit in my bedroom, and I put the swamp cooler in my kitchen, and the increased humidity turned my bedroom arctic.
Downside is that on a more humid day like today it just makes the rest of the apartment feel dank.