What happens if ventilation hole is too large? (room not sealed well at all)

but the inline fan is conneted to a air duct connecting to an air cooled reflector?

I'm having a hard time visualizing the movement of airflow, it seems like if a room had just the right sized hole then air would be rushing in as it is expelled which may make things cooler within the room?

vs

having large openings or no seal, in this case the fan would suck air from the light and out of the room, but it may not help suck fresh air in if the intake holes are too large.

what happens when the intake hole is too large? does this make it so hot air in the room is not evacuated like it would if there was a tiny tiny amount of negative pressure?

it seems that this is the case.

Any air removed has to be replaced to equalise pressure, large hole, small hole, gaps under doors, whatever - it will come in to replace what has been removed no problem...

but if the intake hole was smaller instead of having a major major not sealing door then I feel that it would create more turbulence within the room

There needs to be a balance. You want the negative pressure to pull in fresh air and not let out any smell from your room. I have a closet with gaps all around the door. I wasn't worried as much about the light leaks so I did not seal it, my inline fan (4" 160 cfm) was pulling through carbon filter to hood and exhausting into attic. When my plants were in flower the smell would seep out. I decided to put in Panda paper with zipper and sealed the closet also better for light leaks. The negative pressure was too much and the air exchange rate wasn't as good. So I cut a 4" hole and ran some left over ducting (prob should have gone to 6") and that helped, I ended up rigging a 5" desk fan I bought for $15.00 at CVS to it for intake. Now I can seal my closet up and get a better exchange of air. You want some negative pressure.