Odd question about fuma2 operation.

[StarsMars]

On the Fuma 2, the fans spin in opposite directions. (clockwise and counterclockwise)

This is supposed to create higher static pressure, allowing to run at lower speeds.

To me it seems like it would just create more turbulence.

 

I am wondering if there is some science behind this.

I'd like to try it on my cooler with an opposite direction fan.

 

 

[kb5zue]

Look closely at the picture.  The blades of the fan are facing in opposite directions.  So, while the fans may spin in opposite directions, the airflow is still "thru" in a single direction.  The single direction airflow will help in cooling.  The opposite spinning fans will also help create a higher static pressure but another thing, even though the fans are spinning in opposite directions, this will help with the balance of the entire assembly helping to minimize and shaking or vibration that may occur.

 

Good Luck.

[Jurrunio]

Look up counter rotating propellers, the concept is the same (minus the balance of torque, you dont need this in a PC). It's also less effective because of the distance between the two fans.

[StarsMars]

8 minutes ago, kb5zue said:

though the fans are spinning in opposite directions, this will help with the balance of the entire assembly helping to minimize and shaking or vibration that may occur.

 

I didn't think of that. Thank you.

6 minutes ago, Jurrunio said:

Look up counter rotating propellers, the concept is the same.

This is what I was looking for. Thank you very much.

[narrdarr]

tbh the counter rotation of these is 100% marketing. they are just to low powered to take advantages of it or see the disadvantages. nothing against the kaze flex fans. they are great for noise and static pressure* (*for atleast at the speed they operate at). with that said the heatsink is top notch and if you need more out of it. you can always strap some p12s to it for little cost.

[StarsMars]

4 minutes ago, narrdarr said:

tbh the counter rotation of these is 100% marketing. they are just to low powered to take advantages of it or see the disadvantages. nothing against the kaze flex fans. they are great for noise and static pressure* (*for atleast at the speed they operate at). with that said the heatsink is top notch and if you need more out of it. you can always strap some p12s to it for little cost.

I'm actually using an nh-d15. I ordered a scythe wonder snail 2400 because it rotates in the opposite direction and I want to see if I can get similar results are lower rpms. It's mostly for fun.

 

The arctic p series fans are great btw. Have some p14s in the front of my case.

 

 

[narrdarr]

13 minutes ago, StarsMars said:

I'm actually using an nh-d15. I ordered a scythe wonder snail 2400 because it rotates in the opposite direction and I want to see if I can get similar results are lower rpms. It's mostly for fun.

 

The arctic p series fans are great btw. Have some p14s in the front of my case.

 

 

if your running a high power draw CPU youll see the d15 edge out the fuma 2 at similar rpm. if itsa low power draw CPU you probably wont see a difference. your real test will be swapping fans. putting the kaze flex on your d15 and vise versa. 

[StarsMars]

2 minutes ago, narrdarr said:

your real test will be swapping fans.

That's what I'm doing.  Swapping fans on a d15 tower.

[narrdarr]

if you have a high powered CPU I'd really like to see how the new t30 fans handle. they are thicker but supposedly out preform NT both in noise and performance.

[StarsMars]

Just now, narrdarr said:

if you have a high powered CPU I'd really like to see how the new t30 fans handle. they are thicker but supposedly out preform NT both in noise and performance.

Maybe I'll test them. Only problem is they are thicker, so I might need to make different clips or strap it on the heatsink another way. At which point I may want to just find a high performing 140mm

[Dogzilla07]

@StarsMarsZip-Ties are always a good alternative for mounting fans, either 1-2 big ones, or 4 small thin long ones for each corner.

[StarsMars]

So the fan arrived today.

This is not a proper test so take it for what it is.

I ran cpu-z cpu stress for 5 minutes and watched ryzen master.

With the stock fan config, I was hitting 73.7c and a peak speed of 4,055 all core

 

I pulled the front nf-a15(counter clockwise) off of my nhd15 and replaced it with the new scythe ws 2400 (clockwise).

Ran the same 5 minute run

72.3c and a peak speed of 4,087 all core.

 

A minor bump in performance. But surprising considering I replaced a 140mm noctua with a 120mm.

The nf-a15 might be a dated design or not the best match with this heat sink. Or maybe there is something to contra-flow on heat sinks.