Greetings!
It might take a little bit of experimenting to decide whether blowing it in, or sucking it out works best, but heat rises so if it’s for cooling the higher the vent for going out the better. Either way a single fan should work for that part, then possibly a second fan in the back to actually circulate the air back there.
Cheers!
"Be the reason someone smiles today!" ~ Van_Dweller