pharmacan-your cabinet is amazing, i wish i had seen that thread a few hours ago, some great pictures there. it definitely gives me some vent ideas... had no idea i was talking with a professional builder...jeez.
mine is a closet with an access panel to the attic in the ceiling that is currently sealed shut, but i could mount a squirrel cage fan onto it i guess and use that as an exhaust. which would go perfect with
"use a hole saw and cut two 4" holes in a 1'x1' piece of plywood then seal with silicon". then it could be completely light and mostly air sealed...great!


btw-that story you told your neighbor is brilliant, and if i were him id probably believe that mylar was anti-microwave film if you started going into tech specs :error:

al b fuct-
"You're supplying CO2 in hope of not having to draw air in for the op- right? " no im using co2 for increased yields.

"Where is your transpired moisture going? " i exhaust it with a strong fan, so out of the op and into my room. if i answered that wrong please clarify

"Is there no ventilation path for the op airmass?"
as per the hydrofarm instructions i clear the room out every 3 hours, and run co2 with it sealed the rest of the time.

1x1 feet is just the small access door i made at the bottom of the closet door, it is not the actual size of my growspace lol

what am i doing wrong here?

your correct when you say i want a closed path cooltube drawing air from outside op and dumping it back outside. the ventilation path for the op airmass would be the every 3 hour exhaust cycle with the strong fan.

from your questions it sounds like im doing something very very wrong here

what is it?