Indoor grow room exsaust and vent help!!

Hey guys new to the forum but this is kind of urgent. I'm growing In a attic with 300 watt leds and I can't seem to figure out how can I get ventilation and exsaust in my room. I have a window that is covered up with thick trash bags and reflective sheets (think it's called milar or something) my proble is if I cut a hole in the trash bags to the windo and put a exsaust fan and vent fan then at night my led lights act as a flood light at night and lights up my whole driveway and yard. Is there any way or any thing that I can do to stop this such as a one way screen that you can't see in and no light gets out but you can see out of and the air can still come in. And out. lol I hope you get what I'm thinking of ahah just a lil baked so ya might get my vision I'll re read this in the morning to make sure it makes sense

What size tube?

could you build a box around window on the inside paint it black so from outside it looks like dark attic make box thicker then exhaust tube cut hole in it at bottom of box side put tube in seal it with calk ,foam,tape to keep light from escaping do the same at the top side of box for the heat tube

I was thinking, he could just get a vent cover for like a dryer, paint it black if it needs it and point it up for the light goes up.

Orrr, he could get a vent cover and drape a piece of dark cloth around it and boom?