what CFM do reccomend

namtih024

Active Member
what CFM fan will sufficently cool an air cooled tube 400 hps to reduce heat, im sure it will be larger cfm than the standard exhuast fan equation (cubic feet / 5)
 

209whitebread

Active Member
i have 6 inch air cooled hoods using a 435 cfm fan pulling air out, and the same fan bringing in fresh air, is your hood 4 or 6 inch?? whatever size it is u dont have much of a choice, the bigger the hole the more power the fan will have, i tried an inline fan that said up to 188 cfm, garbage
 

roidrage152

Active Member
Tubes are very efficient to cool, a decent 4" inline will probably do the job depending on your ambient temps. You may need flanges/reducers to match your tube size. Ultimately I would just buy the fan that fits your tube. Can't have too much cooling, and can always use a speed controller if you want. Those cost like $20. I cool 4000w in hoods (less efficient than tubes) with about 1400 CFM with a speed controller to bring heat up at times.
 

gargantuanganja

Well-Known Member
I have a 635 cfm fan running through an enclosed Magnum-XXXL hood with a 1000w HPS and it still gets pretty hot in there so I added a portable A/C unit. I'd recommend something above 400 cfm for sure
 

namtih024

Active Member
thanks guys, its a 6inch tube by the way, ill prob go with something in the 400 to 600 cfm range. i idea is to try and outfit a box with an oversized light while maintaining optimal temps, to increase yeild in a limited space.
thanks again, and anyone with experience using a 400w hps in a cab feel free to chime in and offer some thoughts
 

mrmadcow

Well-Known Member
..... i tried an inline fan that said up to 188 cfm, garbage
I have a 635 cfm fan running through an enclosed Magnum-XXXL hood with a 1000w HPS and it still gets pretty hot in there so I added a portable A/C unit. I'd recommend something above 400 cfm for sure
damm! I run a 400 hps in a hood w/ 2 pc fans,1 @ the start of duct pushing air & 1 @ the end sucking air out -straight shot,4 in duct, no bends or filter. & the hood is warm but not hot to the touch. the air is drawn from another room in the basement so its cool going in.
 
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