vent help....

pyrosfire

pyrosfire

Active Member
hey guys and girls, so this is my second grow and second cabnet, which is in the shape of a large bedside table, problem is its to noisey and way to hot (37c at peak).
now the box is 45x30x60, is mylar lined, running 8 20w cfls and being cooled with only a 38cfm computer fan (8cm) throught odoursourb carbon cloth and only has a serries of passive vents
so i want to add a intake fan and hopefully take the pressure off the exausht lowering noise and possibly and an extra exhast to lower temp
so the question is what sizes and configureation should i use????
 
fabfun

fabfun

New Member
pyrosfire said:
hey guys and girls, so this is my second grow and second cabnet, which is in the shape of a large bedside table, problem is its to noisey and way to hot (37c at peak).
now the box is 45x30x60, is mylar lined, running 8 20w cfls and being cooled with only a 38cfm computer fan (8cm) throught odoursourb carbon cloth and only has a serries of passive vents
so i want to add a intake fan and hopefully take the pressure off the exausht lowering noise and possibly and an extra exhast to lower temp
so the question is what sizes and configureation should i use????
Click to expand...
the carbon cloth is restricting air and better to add another exhaust fan then to use it for intake
run passive intake
 
pyrosfire

pyrosfire

Active Member
ok sounds sweet thanks fabfun tho did a real unscientific test, by opening and shuting the door slowly to see what the difference in noise levels were to try figure out how much more venting i would need and i think it would kill the stealth way to much, unless i realy geeked out and desinged a venturi valve or some thing for the intake, so may have to up it to fan intake, for now im cooling with water vaper which has my humidity up around 90% and temps around 29c, so its short term but working well.
so would a small centrifuge fan be quiter? and would they have better pressure capablities, just want a clear plan before i cut holes in the side of my hand built cabnet
 
fabfun

fabfun

New Member
pyrosfire said:
ok sounds sweet thanks fabfun tho did a real unscientific test, by opening and shuting the door slowly to see what the difference in noise levels were to try figure out how much more venting i would need and i think it would kill the stealth way to much, unless i realy geeked out and desinged a venturi valve or some thing for the intake, so may have to up it to fan intake, for now im cooling with water vaper which has my humidity up around 90% and temps around 29c, so its short term but working well.
so would a small centrifuge fan be quiter? and would they have better pressure capablities, just want a clear plan before i cut holes in the side of my hand built cabnet
Click to expand...
hey thats same way i tell too
u are learning
 
K

kushnotbush

Well-Known Member
Well I can tell you this, IMO you need to NOT have an intake fan on a small box. You need to measure out your intake dimensions and your exhaust dimensions, your intakes should be about 2 and a half times the size of your exhaust. I would double up your exhaust and set one of the fans to run all the time and the other to only run when the lights are on. Also with your passive intakes the right size and your exhaust blowing into a duct or some kind of muffler your still stealth. Also just to add the reason I said two and a half times the size on the intakes is so you can cover them with some sort of filter and them still be stealth otherwise go for twice the size. Just my suggestions based on my experience. Good luck and happy growing!
KnB
 
pyrosfire

pyrosfire

Active Member
yip my guesstamet was about right then so im currently ordering more carborn cloth ect as we speak to do the vent it comes in 30x30cm squares so should be sweet, just saddnes me to cut out half the back wall. so is it possible to go to big?
now if i got some acustic foam and built a flap lined with it over the exhast alowing 4 or 5 cm of breathing room do you think it wold be efective
 
reverof

reverof

Active Member
I will point you to my signature, check out the under $30 inline fan
Works VERY well in a 6x8 room for both intake and exhaust
 
fabfun

fabfun

New Member
kushnotbush said:
Well I can tell you this, IMO you need to NOT have an intake fan on a small box. You need to measure out your intake dimensions and your exhaust dimensions, your intakes should be about 2 and a half times the size of your exhaust. I would double up your exhaust and set one of the fans to run all the time and the other to only run when the lights are on. Also with your passive intakes the right size and your exhaust blowing into a duct or some kind of muffler your still stealth. Also just to add the reason I said two and a half times the size on the intakes is so you can cover them with some sort of filter and them still be stealth otherwise go for twice the size. Just my suggestions based on my experience. Good luck and happy growing!
KnB
Click to expand...
i never run a fan on intake always passive then u get negative pressure in room

instead of blowing air into room then blowing it out
u suck air in and through your your room to the exhaust
creates a vaccum
 
pyrosfire

pyrosfire

Active Member
reverof said:
I will point you to my signature, check out the under $30 inline fan
Works VERY well in a 6x8 room for both intake and exhaust
Click to expand...
looks good but i think ill go with kushnotbush and fabfun i think tho ive taken 3 lights out and its taken the temps to about 28
 
pyrosfire

pyrosfire

Active Member
so i now have my temps flotting bettween 77-82f now thats sorted ive had to put the water vaper back in as hymidity is around 10 and my leafs are drying out so hey there you go so not sure but think i can pump them to around 50%
 
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