Recent content by old timer 4311

Isnt area = pie*r squared? So r=3 area = 28"

Also, did the experiment with my fan at full power vs 1/2 and the temp fell about 4 degrees on full power. Leads me to believe that the 6" ducting can handle more than 75cfm. However its a very short run (maybe 2.5 feet). Im sure it would loose efficiency over a longer run.

I would be interested to see what people with hvac backgrounds have to say. The area the calculator spits out is pretty large. Considering the area of a 6" duct is about 28", getting up to over 100 sq in would be difficult. I was planning on usong 90 pvc elbows but using 4" pvc i would need...

So what does that formula calculate? Came up with 28.7 6' duct run 2 90* elbows Filtered and 600 hps

Interesting. Makes sense in theory but when i run my 400 cfm at about 50% power and 100% power it seems like a larger volume of air travels through the box. Ill do a test tonight and see if my temps fall based on 50% vs 100%. Wouldnt the max cfm also be a product of velocity? So my...

Hey guys, Planning next grow box and was wondering if there was a formula out there to calculate the area of passive intakes. Box will be approx 63 cubic feet. (3x3x7). Exhaust fan will be 6" 400 cfm hydrofarm. Thinking there must be some math formula to calculate the most efficient...

Totally agree. Its been 5 years since last grow and love getting back into it. Cant wait to get a real grow going. Just need to finish a few things, router table and portable base for my table saw. Love building things and love growing. Should be fun times coming up.

Ended up with a 6" hydro farm. I also installed a speed controller. Running it at low pulls a hell of a lot of air. I agree with the hps. Just messing around getting back into things with the cfl. Will prob use this box to keep a male in eventually. In a few months ill build a much bigger...

Thanks guys. Ended up getting a 6" hydro farm which i'll install this weekend. I agree the 4" will get me where i need to be for now but the 6" will be better for the future. Ill see how loud the fan is before bothering with the insulation. The box is in the basement in my workshop so noise isnt...

Hey guys, After taking a 5 year break I'm getting back into growing my own stash. Previously had a 4x4 hydro setup in college with air cooled hps. Now I'm down sizing. I built a 2x1x4 (LxWxH) plywood box. I have it setup to run max 12 23w CFLs. I cant seem to keep the temps down using...