intake/exhaust

Big_Frosty805

Well-Known Member
Built a 4x8x7'6" grow box with reflective lining. Running two 600 watt air cooled digital ballasts, a 210 cfm carbon filter with a 250 cfm exhaust fan along with another 250 for the lights and one more for intake as well as a wall mount oscillating fan but cant keep it under high 90°s. No plants in it yet, just test running while clones and seedlings are vegging in closet

Any suggestions to bring it down, thinking about grabbing another 250 inline or maybe air conditioner???
 

Big_Frosty805

Well-Known Member
And
Whats air temp of room the tent is in?
If intake air temp is not cool, then no amount of fans will work.
It stays around 65 and is gonna draw from outside and I'll be running them at night. I still want to add one more 250 cfm inline for anothr intake Im pretty sure an air conditioner will keep it plenty cool
 
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hydrogreen65

Well-Known Member
Cool, you should be set then. Those portable ac's work great.
I would get ac, then try to run as few exhaust fans as you can get by with. If not the AC will end up running all the time.
 

booms111

Well-Known Member
Ok , try this. Turn your intake fan off. Make sure your intake holes are 2x bigger then your exhaust is. Passive system...If your intake and exhaust are same size fans your creating a equal pressure which isnt pulling the hot air out properly.
 

Big_Frosty805

Well-Known Member
Thanks. Ima try tweekin around with it tonight after work. Last night I let itrun for about 6 or 7 hours with just the one 600 watt mh running and opened up one end of the cool tube and was able to keep the temp at 83°and 77°with the door open and since I only have 14 plants.. still babies and clones I think I can leave it open. It's in a guest room I don't use and I'll be vegging 24 hours so I'll try that till I need the second light and cam buy another family or ac.
 

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skunkd0c

Well-Known Member
seems like your fans are too small to me for 600w lights in such a small space too
personally i would use 2 large fans and a passive inlet

an 8 inch fan blowing cold air through your lights
you can take the air directly from outside blow this cold through the lights

another 8 inch fan would then be more than enough for air changes to bring fresh air into the space from the passive inlet

i think your problem is caused by the small /enclosure air space you have
the lights are able to heat up all the air in this space quicker than you can remove it with the fans you have
rather than trying to remove more air from the space more quickly to lower the heat this is a battle you cant really win in such a small space even with very big fans

it is better to try to cool the lights down directly before they can warm up the air in the space in the first place
reflectors should be completely cold to the touch
this means blowing high pressure cold air through the light system this will create positive pressure in the light system
and no extra filter will be needed

peace
 

Big_Frosty805

Well-Known Member
Well I ended up buying an air conditioner and hooking that up to cool the lights and that seems to be working pretty well. I also have it bringing in cool air as well. Also I didn't realize til I spoke with a couple friends that are growers for a few dispensaries that when I put my plants in the box the temp is gonna drop up to 10° due to them sucking up some of the heat
 
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