Math question for the big boys..

[Firepower]

i planted my my 2nd grow early January outside in peat pots and some are already flowering at 2 inches tall!!
now they are coming in to the new box i built with a 100W HPS and 4- 120 w CFLS
my cabinet is going to have its own ventilation separate from the light box since there will be a glass division between the two.
i need to know the amount of CFM appropiate for my cabinet fans.
measuremnets are 15" depth x 35" width x 48 height ( 3 feet tall 4 foot wide)
I would like to know what the least amount of cfm that is reccomended for my specs and what cfm would be considerd more than enuff?

im doing some tricky ventilation shafts for this cabinet and space is an issue, if anyone can help it would be greatly appreciated.. thanks..:aok:

 

[umbra]

I don't know of any 50 to 60 cfm fans, but that wpuld be min for your space. easlier to find 100 cfm, computer fans are about that. max would be about 300 cfm. there is quite a difference in price between the 2. the least expensive will probably do the best job.

 

[Bent526]

I went down to my local electronic parts surplus store and bought two squirrel cage fans rated at about 50 cfm and built some ducts out of aluminum for my cabinet. They work great but are a bit loud... bonus is that they were $4 each, and I had an extra 12v power supply around the house.

I like using DC too because it's much harder to get an electric shock

ps. also you can get a potentiometer (depending on current draw of your fan you'll need to calculate size) for speed control. Go here for the math: http://www.blackfiveservices.co.uk/fanspeed.shtml

 

[Firepower]

Thanks Guys, i actually found a radiator i bought for my bike and it had a nice power fan on it, gonna try and incorporate that in somehow. lol

How do you actually come up with the volume of my box?

 

[jjsunderground]

id say vent directly with a 4 inch inline fan, hold on ill get you one. http://www.hydroponics.net/i/133756. you may have to also put an air intake vent in the cab, or it wont work. but this would be perfect put it up top close to the lights. use a 4 inch dryer exhaust tubing mount. then put the intake grill towrads the bottom, as low as possible. this is just what i hada thought of doing for a small grow cab, but you dont have to use this approach if it doesnt suit your taste. peace.​

 

[benamucc]

Volume = Length x Width x Height 15 x 35 x 48 = cubic inches 1.25 x 2.91 x 4 = 14.55 cubic feet