Does rad thickness affect fan requirements?

[Zachattack3ee]

I am aware that the fpi of a rad affects the static pressure required of a fan quite a bit due to the restricted airflow. However, does the thickness of a rad make a difference? Surely more surface area = more force needed to push air through BUT ALSO, the air is already going to be moving in the right direction as in it's not hitting the end of a fin like when it enters the rad (which i assume is why more fpi causes airflow reduction). This may be the wrong thought process due to rad roughness and therefore friction causing airflow compromise. ALSO I always see "high fpi rads are for high speed fans" is this true or is it a simplification of the statement "High fpi rads are for high static pressure fans" for example would a stock fan at 1500 rpm perform equally to the renound nf-f12 at 800rpm? Thank you and sorry for long questions. Finally I'd like to mention that I am aware of how many tiny little things make tiny little differences but idc, I want a full, thorough explanation even if it requires hours of reading through other articles because i enjoy learning about all this. ***This question was already asked back in 2k16 and received no answers but with parts on the way, I kinda need answers soon to help me decide on cooling solutions and i thought perhaps reposting will get new people to read this and in turn, answer. Thats the plan at least...***

 

[dstarr3]

High-FPI rads are going to require high static pressure fans, not high speed fans. Speed and pressure are not interchangeable, and if you're going with a high-FPI rad, you'll need high static pressure fans to go with it. Using a high-speed fan when you need static pressure is just going to result in a lot of noise and not a lot of cooling.

Increased thickness does indeed increase resistance, but generally not as much as FPI. If you get a super-thick, super-high FPI rad, really all you can do is set up a push-pull configuration with double the number of fans.

 

[Zachattack3ee]

High-FPI rads are going to require high static pressure fans, not high speed fans. Speed and pressure are not interchangeable, and if you're going with a high-FPI rad, you'll need high static pressure fans to go with it. Using a high-speed fan when you need static pressure is just going to result in a lot of noise and not a lot of cooling.

Increased thickness does indeed increase resistance, but generally not as much as FPI. If you get a super-thick, super-high FPI rad, really all you can do is set up a push-pull configuration with double the number of fans.

So if I were to want lower noise could I run lower fpi rad with lower speeds but moderate thickness to make up for these? Does a rad 2x as thick scale with 2x as good cooling?

 

[dstarr3]

Typically, if you want low noise and still good cooling, the best way to achieve that is with more fans running slower. If you can fit a 120x3 rad in your case, or even 120x4 and fill it with fans, each of those fans can run very slowly and generate almost zero noise, while still maintaining excellent cooling performance.