Just put a inline inside the tent and vent it out of the tent and leave window a tiny bit open will create enough passive intake man
If u really wanna block ur window what u do Is hang some Venetian blinds tilt them a tiny bit up then behind that hang a curtain blinds then behind that hang ur black plastic unless u get full sun block curtains to hang behind the venetians
In the upstairs bedroom do u have wall vents
View attachment 3537362View attachment 3537363 that's my full sun block curtain in front of my venetians and how I vent with out opening a window then just leave the rooms door open a little