Negative pressure

[larsson]

how do i create negative pressure i have a 4 inch exhaust pulling outside through carbon ilter with no intake my grow is in a closet i just made a whole at bottom o door to intake HELP ME lol

 

[solocup]

Sounds like you have already created negative pressure.I would think if the intake is smaller than the exhaust it would work.I have a 4 inch inline fan in a 3x3 grow tent that has 4,4 inch openings for intake and it still creates negative pressure...

 

[larsson]

thanks my original issue is that im still smelling WEED lol and i dont understand why lol

 

[Wacky Kush]

Not to sound silly but any leaks in the exhaust or filter?

thanks my original issue is that im still smelling WEED lol and i dont understand why lol

 

[larsson]

yeah blowing the exhaust into a 4 inch carbon ilter

 

[Wacky Kush]

Have you tried sucking through filter and blowing out filtered air ( filter inside cab) ?

yeah blowing the exhaust into a 4 inch carbon ilter

 

[larsson]

thats not really practical in my room

 

[Wacky Kush]

New or newer filter no leaks?

thats not really practical in my I room

 

[larsson]

its brand new and i checked no leaks maybe its in my mind lol

 

[Wacky Kush]

Mind listing your set up ? Dimensions, cfm etc.

its brand new and i checked no leaks maybe its in my mind lol

 

[larsson]

its a closet in a bedroom its 7' high 5' wide 2.5' deep 400 watt hps light 4inch extractor to exhaust just a hole at bottom passive intake as i said exhaust blows through carbon ilter got 4 northern light girls in there going great i got ona blocks around the bedroom not sure much air is being pulled

 

[larsson]

i really appreciated this help pal

 

[Cultivator]

blowimg through the filter wont be as nearly effective as sucking through it and extracting dirty air. try cutting a hole in the ceiling and extract in to that, pulling air through filter.

 

[larsson]

thanks i been creating some room today so tomorrow im going to put the carbon filter inside the grow room guess it was a newbie mistake having it outside cheers you guys make it sound so easy

 

[larsson]

well thanks everyone put filter inside the cab no odour at all now. kinda missing that sweet smell lol

 

[SWvoodoo]

Close your cupboard light a lighter or match outside your intake if it sucks the flame towards/into the cupboard you have negative pressure. I also use this method to check my tent, ducting etc for leaks. If not you will need to seal as many gaps as possible sticky back foam may come in handy and a heap of ab-duct tape.