I'll go, since everyone seems a little shy right now.
EcoFans(heat powered stovetop mini fan)
I have one, after the first one died after giving several years of free assistive convection.
They ARE different.
My original was 3 blade, 5" width. It MOVED the air. I found it hard to imagine all those people thinking they were useless, toys, or cosmetic. I believe it got heat soaked, which will kill the peltier module...(electronics that make it work)
My new one this year is being 'tweaked'...It's a 4 blade 5" width. This one's designed for a Mr Buddy propane heater, but it's also a stovetop.
It's blades are terrible, barely push any air. I'm setting blades now, but honestly we haven't burned this year more than a handful of low burns so i can't tell you the final result.
HERE is a tip. Make sure the one you try has a Bi-Metal strip on the base. This is supposed to protect the module by lifting the foot off the stovetop if it gets too hot.
Here is a hack. You can buy modules off Ebay, Amazon for a dollar or two. Get a DVD/CD player(PC)at a thrift store for the motor. Use a chainsaw cylinder head for the heat sink. Buy aluminum fan blade off Amazon/ebay.
If you/someone can wire/solder you can make a multi-fan for a small cost.(Ecofans are high this time of year)
BONUS/ when the power is out, your ceiling fan, room fan isn't going to get warm air to the far areas without 120v. The Ecofan will stir the air.
THIS is important. YOUR stovetop temp determines the fan RPM. If YOUR specific stovetop only gets 340F, you are not going to get high CFM.
I have a sheet metal Fisher Grandpa Bear from '75?. When the stovetop temp clears over 624F, the fan wants to take flight. It roars, and You can feel circulation 15 feet away.(the old one, #1)
No brands, just recommend wider the better, and get a safety bimetal foot in yours. I bought the 'build your own' parts above, just no time yet to get to it.