Hi D, have you heard of box fans/ box ventilators?
They do a really good job to speak from my own experience.
I use them succesfully for years now.
The rotating grid in front of the fan wheel directs the air in every direction ( left right and up and down) and circulates the air very well.
As far as i know there are 3 speed and 4 speed models out there, both max 50W. Level 1 is enough in a 4x4, so consumption is low.
Just make shure it 's not to close to the tent wall because it sucks the tent an it can suck air only from the side and has to work harder.
That's the way I fucked one up. But aside from that, mine were pretty durable. I hang em with S hooks ( on the grid fan wheel housing on the back).
I can get them in my area from 20€ on, so worth a try.
Have a nice sunday!