intake or exaust?

so my setup is 52in tall 52 wide and about 24in deep. im running an 8 lamp t5 and a 4 lamp t5 bolth 4ft. the room is 90% seeled or so. with all the lamps going the temp hits 100 degrees F. im running a 55-110 inline fan carbon filter combo for scrubbing and exaust http://www.hydrowholesale.com/Carbon-Filters-and-Air-Purification/Viagrow-55-110-CFM-4-Carbon-Filter-2TD-Series-Fan-COMBO.asp . ive ordered a 171 cfm inline fanhttp://www.hydrowholesale.com/Inline-Fans-and-Blowers/Hurricane-Hurricane-4-Inline-Fan-171-CFM.asp to help exaust or intake cool air. so the ? is should i intake cool air from the crawlspace below my house or should i hook the 171 cfm up to the 55-110 inline fan carbon filter combo to exaust more air? or do i need to do some of bolth? smell is an issue as i live in a tri-plex appartment my neghbors smoke trees but dont know what im doing and id rather they didnt know. +rep for good replys thankz in advance for your help!

$waGgEr said:

so my setup is 52in tall 52 wide and about 24in deep. im running an 8 lamp t5 and a 4 lamp t5 bolth 4ft. the room is 90% seeled or so. with all the lamps going the temp hits 100 degrees F. im running a 55-110 inline fan carbon filter combo for scrubbing and exaust http://www.hydrowholesale.com/Carbon-Filters-and-Air-Purification/Viagrow-55-110-CFM-4-Carbon-Filter-2TD-Series-Fan-COMBO.asp . ive ordered a 171 cfm inline fanhttp://www.hydrowholesale.com/Inline-Fans-and-Blowers/Hurricane-Hurricane-4-Inline-Fan-171-CFM.asp to help exaust or intake cool air. so the ? is should i intake cool air from the crawlspace below my house or should i hook the 171 cfm up to the 55-110 inline fan carbon filter combo to exaust more air? or do i need to do some of bolth? smell is an issue as i live in a tri-plex appartment my neghbors smoke trees but dont know what im doing and id rather they didnt know. +rep for good replys thankz in advance for your help!

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just hook up the exaust. your going to still pull fresh air in. and 100 deg is way too hot, try and get it under 90 deg and get it to drop 15 deg when light is off

The question is for such a small box, why are you unable to keep temperatures down with such an adequate fan? First thing I would do is remove the carbon scrubber and see how it effects the temperature of the box, and then after you get that answer you can further investigate as to what could be causing the issue.

the temp of the "fresh air" is key here..for example: if ur pullin in air from a room or crawl space thats 85F ur never gonna drop below that 85 inside ur box!! so find some way to drop the temps outside the box or wherever you're pulling the air from. what size intake hole(s) do u have?? its been coolin off quite a bit here in the midwest so the crawl might be cool enough but ud have to filter it to keep undesirables out ,and before u go drilling a hole in ur floor...try leavin a window cracked if possible and a fan blowin in the direction of ur box!! if u dont have one a desk fan (or 2) blowin between bulbs and canopy will help alot when u find a source of COOL air.. .02

o0kons0o said:

just hook up the exaust. your going to still pull fresh air in. and 100 deg is way too hot, try and get it under 90 deg and get it to drop 15 deg when light is off

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agreed id like to have temps at 80, and with half the 8 lamp t5s bulbs off the room stays at 80 just fine.

IndicaDom said:

The question is for such a small box, why are you unable to keep temperatures down with such an adequate fan? First thing I would do is remove the carbon scrubber and see how it effects the temperature of the box, and then after you get that answer you can further investigate as to what could be causing the issue.

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went for that kept temp at 90 or so with all the lights goin for and hour or so. also i dont have plants in yet so im doing dry runs till the issues settle down. I thinks the t5s are just giving off heat outside room temp is 70 at the most.

bazookajoe said:

the temp of the "fresh air" is key here..for example: if ur pullin in air from a room or crawl space thats 85F ur never gonna drop below that 85 inside ur box!! so find some way to drop the temps outside the box or wherever you're pulling the air from. what size intake hole(s) do u have?? its been coolin off quite a bit here in the midwest so the crawl might be cool enough but ud have to filter it to keep undesirables out ,and before u go drilling a hole in ur floor...try leavin a window cracked if possible and a fan blowin in the direction of ur box!! if u dont have one a desk fan (or 2) blowin between bulbs and canopy will help alot when u find a source of COOL air.. .02

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there is a predrilled 4" hole for a dryer so i dont have to chop the place up too bad..and i have a small fan maybe too small. the crawlspace is cool like the outside air here in the midwest... its snowing even.

went for that kept temp at 90 or so with all the lights goin for and hour or so. also i dont have plants in yet so im doing dry runs till the issues settle down. I thinks the t5s are just giving off heat outside room temp is 70 at the most.

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Hmmm, I would try turning off one set of lights to see how that effects the temperature also here is something else that might help you out if you are using a 4" predrilled hole as your passive air intake.

The Home Ventilating Institute recommends one square foot of open air inlet per 300 CFM of ventilation fan capacity.


I am thinking that your carbon scrubber/fan combo isn't doing much, I am going to use the low end 55 CFM for my numbers. I see that you got another 171 inline fan, and were asking about the arrangement. I would suggest hooking up the 171 in-line fan to the carbon scrubber/fan combo on the exhaust. This would give ample pressure to push through the carbon filter if that is the hold up, on top of that 171 + 55 CFM = 226 CFM.

That means if you want a 1 square foot hole for 300 CFM, that means you want a 226/300 = .75 cubic feet x 144 in. per cubic foot = 108 square inches. Here are your options...these are for a 256 CFM fan.

1 hole - 12.5 inches in diameter.
2 holes – 8.84 inches in diameter.
3 holes – 7.22 inches in diameter.
4 holes – 6.25 inches in diameter.
5 holes – 5.59 inches in diameter.
6 holes – 5.11 inches in diameter.

just for future reference. fans are better at pull air than pushing.

keep the intake passive. you want a centrifugal blower. regular fans struggle to maintain any type of vacuum.

smell is an issue

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Exhaust into the crawl space and draw air from the house, as long as its under 80 your fine..

Workin with the same issues... hah.