# duct size?

Discussion in 'Grow Room Design/Setup' started by Jonathans, Sep 29, 2010.

1. I have been trying to figure out what I will need for my intake, and think I need about 160 square inches. I was thinking of using either 14 or 16 inch ducting, but I can't get ahold of any, and it is much more expensive. I guess my question is: Are two 8 inch ducts the same as one 16 inch?

2. Yes. If your looking for large sized ducting your going to have to visit a ac business that sells to the general public. You won't find that at home depot. Too specialized

just use the two 8" if it works for your application

3. To me it seems like two 8 inch ducts would not be the same as one 16 inch. I drew up a quick image in paint to describe my train of thought... can anyone explain if this is the same with circular ducting?

4. I might just buy a box of 10 or 12 and do two of those.

5. An 8" duct provides 350 CFM of free-flow fresh air
Common duct sizes and area (PI * R squared):

6" = 28.27 square inches
8" = 50.27 square inches
10" = 78.54 square inches
12" = 113.10 square inches

does this help

6. Thank you Tihspeed, that was what i was looking for.

7. Did someone miss the "PI r squared" in high school lol just messin