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So I just upgraded to a 250 watt light in my cab... Was wondering how big of an exhaust fan ill need to keep it cool. Cab is 2' wide 2' deep 3' tall. Grow either 2 or 3 plants depending on strain. Was thinkin like a 180 cfm would be enough. Or should i get like a 265? Thanks all.
Sorry cab is 2' deep 3' wide and 43" tall exactly
CFM stand for cubic feet per minute.
The size of your cab is 22.2 cubic feet of space.
180cfm would circulate the air in the box around 8 times per minute depending on location inside the box.
now it would all depend on what type of light you are using. I am guessing that 250watt means 250 watt HPS. Right?
a 256 would be a better idea to me. Better safe then sorry and if you don't already have the 180cfm fan then it wold be better to not waste money and have to buy another if the 180 didn't work for you.
the 180 should work but as the plants grow and fill up space you would notice an increase in temp so the more the better a 256 would be fine. 180 might be though.
final answer. get the 256cfm.
Yea its a hps also have mh conversion. No i had a 140 cfm so im just goin to upgrade whole cab. Do you think i should go more than 256?
depending on how big you end up going.
256 is actually a lot depending on how its used. But more then that could be used.
How big do you plan on going?
This will be it for a while... Dont want to overdo the exhaust and have it too cool too fast. I want to be able to keep the light close so i dont lose precious light. Have a flexible duct going into utility room that will have a homemade 10" carbon filter... Forgot to mention that. Needs to pull air thru that as well.
My first cabinet was ~2x2x4.. i had 2 muffin fans~55 cfm each~ one for intake and one blowing out... with a 250... DID NOT DO THE JOB... and were kind of loud as F#ck.... So i got 4 inch vortex and built a cool tube... and there were no problems.. Kind of overkill.. it runs about 5 over room temp now... Dont know if that helps any.. but... there it is.
Do not skimp on ventilation!