I wonder if they move double the air, does the S9 move 250 FPM, S15 500?

exactly - so i am thinking of doing double tall same width and exit to 4" for mine only because I already have 4" to 6" adapters on the 6" ducts already but I still have some on 4" ducts as I upgrade those to 6" i will forego the 4" to 6" adapters and just use a 6" right off the miner. eventually will swap them all out as the ocd aspect will bug me lol.

right now I have 4" 3d printed piece on the back of the current S9's like this



which directly connects to one of these - immediately opening it from 4" to 6" --- originally I ran them as 4" directly outside but decided 6" would be better, rather then make all new pieces to hook to the miner, I used a 4" to 6" and just ran the ducting from the adapter to outside (distance to outside is less than 1 foot. The air does not have far to go before being vented.



so my idea is to use the 3d printer to make something similar to this shape that will mount to back of miner and hook to my 4" to 6" adapter - thus the only thing I am replacing is the piece on the back of the miner.

the other idea is to just make it 6" remove the 4" to 6" adapter completely.

Yeah, don't go to 4" then to 6" it will restrict your flow, go straight to 6".

it is a friction issue due to smaller duct.

lets say the rectangle is 6 x 12 = 72 sq inches

a 4 inch duct is  only  4 x 3.14 = 12.56 sq inches  not likely to work  as a guess 95% no way

and a 6 inch duct is 9 x 3.14 =  28.36 sq inches  may work  maybe I would try it out

also the length of ducts cause friction  so shorter the better.

I don't remember the formulas for figuring it out.

you may find  the 6 by 12 rectangle  ends up morphing into a 7 inch duct  they do exist

that would be 6 x 12 = 72 rectangle

and 12.25 x 3.14 = 38.465 7 inch duct  

round duct I use pi x r x r   or 3.14 x 3.5 x 3.5 = 38.465

maybe 7 inch they do exist.

also both the s15 and the t15 have low power settings  which could help if the six inch duct is too small.

let us know once it sets up.

Just don't neglect the airflow around the miner, it is important. Ducts should not be directly attached to the miner in my opinion, but to a box where the miner resides inside instead.

Is it true that Antminer S15 has serious issues with its PSU?