ventilation question.

[stopcallingmedude]

hey guys, simple question that i can't figure out. my room is 252 cu. ft. it is generally air tight, but i'm sure there are some leaks that i just can't stop. i have a 180 cfm fan. i have a basement window that i can vent out/in from. do i need to be exhausting air (exhaust) or bringing air in (intake)? or both? secondly, how does it work? does anyone have anything with pictures that would make it easier to understand? thanks. 'preciate it.

 

[smoke and coke]

have the fan suck from the room to outside. just a passive intake is all you need. i used back to back 90 degree elbows shaped like an "S" painted flat black inside to keep light out. here is a link for ventilation.
https://www.rollitup.org/view.php?pg=faq&cmd=category&id=67

 

[docd187]

have the fan suck from the room to outside. just a passive intake is all you need. i used back to back 90 degree elbows shaped like an "S" painted flat black inside to keep light out. here is a link for ventilation.
https://www.rollitup.org/view.php?pg=faq&cmd=category&id=67

if your just gonna have that one fan do what smoke and coke says. another option are you could get a bigger fan, one that will completely exhaust your room every minute, for the exhaust and use the one you have for an intake fan to get fresh air coming in and old air out.

 

[dahamma]

If your room has air leaks don't worry about intake. All you will need is an exhaust to create negative air pressure in your room and get rid of smell

 

[stopcallingmedude]

If your room has air leaks don't worry about intake. All you will need is an exhaust to create negative air pressure in your room and get rid of smell.

so i should leave some air leaks on purpose then? i guess my next question is, what about stale air? i'm growing in a basement, so should i be worried about not getting enough quality air to the plants, or will the fact that the exhaust fan is running negate that problem? i've got CO2 being pumped into the room. worries or no worries? thanks.

further info: i'm using two 400 watt hps and the exhaust fan would be near the top of the grow space to vent hot air/smell/stale air.

 

[smoke and coke]

i have the same size room. im using a stanley blower to exhaust through 6" ducting. i have a 7" passive intake that feels like it has a fan in it even when the blower is on low.
you dont want air leaks on purpose. not only light can get out it can also get in then. not good for flowering.
you may need cooltubes for those lights. i would do a dry run before putting in plants to make sure.