@HagssFIN: Thank you for the recommendation. From what I can see, the Delta QFR1212GHE has 211CFM, the Sanyo Denki 9LG1212P1G001 I posted had 247CFM. I was looking for an upgrade.
I am very limited by where I can keep my miners at least for now and cooling is an issue. The original fans keep up but barely.

@philipma1957: Thank you, I'll take a look. A shame the Sanyo fan doesn't work with the S9.
If I ever find a dedicated high power fan controller, I'll let you know as I was thinking of putting this on it : https://www.mouser.com/ProductDetail/Sanyo-Denki/9CR1212P0G03?qs=t9Lg9qrXjEzaIskuv0a4hg%3D%3D

Also: would this work? https://www.mouser.com/ProductDetail/Delta-Electronics/AFB1212GHE-C?qs=Tx9Tc1LIQ%252BGtXNKmVITynw%3D%3D
my guess is not, since it doesn't have a tachometer and PWM but I want to explore all options before I place the order.