Stacking two fans?

[nerdlogic]

Unless you have some sort of special left handed fan, with blades angles the opposite way, um (LOL) one fan will be sucking and the other one will be blowing!

Exactly what I was thinking, but you never know...

 

[DesireUnkind]

Temp drop by 5 degrees

After putting the Smartfan2 on my heatsink, my temps dropped for a total of five degrees. Although the fan is kinda loud, it's worth it to me to keep it under 50C.

idle 36
load 48, Prime95
load 44, FAH

Thanks for all the tips and suggestions. Really helped with my decision on what fan to buy and what to do.

 

[Skulemate]

Actually, I was watching TLC (the Learning Channel) just last night, and saw something similar to this....

I saw one of those HUGE MOFO choppers, the one with TWO blades, and they were going opposite directions...

(It's one of those long choppers that looks like a hot dog.)

Think of it this way... If it's good for the chopper, it's good for your PC case

Not exactly. The reason those blades spin in different directions is to remove the need for a tail rotor... the torques from the two motors cancel each other out.

 

[TheMightyBuck]

if you had a helocopter with only one set of blades, then the body of the chopper would spin around uncontrolably....

the purpose of the tail rotor is to keep the chopper from spinning around, and only letting the blades spin....

 

[Cjwinnit]

Hmm, interesting thread..

I have 2 "case" fans, one 50mm and the 80mm fan in the PSU. The 50mm spins anti-clockwise (as you look into the fan, and the air is being blown away from you face, the blades spin anti-clockwise). This is the only fan that fits nicely in the back of the case. Where can you get clockwise fans. Anyone?

 

[ducksonetime]

Sorry to dig up such an old thread but I've been trying to find some solid info on stacking counter-directional fans and wanted to share.

I've found this video that shows their counter-directional fans focusing airflow significantly, but I'm not sure if the total mass of air moved is larger.

There are readily available clockwise rotating fans in the Arctic Cooling Fxx Pro series (replace xx with fan size, eg F8 = 80mm). They're relatively cheap too.

I've got a couple on the way so I'll do some testing and report back.

Cheers.

 

[ducksonetime]

Also, it seems the focused airflow effect is the more desirable characteristic of these counter-rotating (or contra-rotational) fans/propellers, not the countering of inertia on helicopters.

 

[ehume]

You have to play with fans to get a sense of how rotten the idea is. I even tried stacking counterrotating fans. Blech.

counterrotating fans work because the second set of blades adds static pressure to the two-layer system, not CFM. There is a white paper by San Ace engineers that explains it. But notice: the set of blades are deigned to work together. And usually there are fewer blades in the second set than the first set. Think 7 blades and 5 blades.

The reason two counterclockwise fans do no increase anything is because they set an airflow distortion behind the first fan.

If you have extra fans, it's fun to play with them an get a sense of what they do. I heartily recommend the exercise.

And I forgive you for necroing the thread. Remember that those were the days when people didn't know jack about airflow.

 

[Soulcatcher668]

Stacking works guys.... I swear...

 

[caddi daddi]

that's with like 40 fans on one rad!!!!!! I likey!!!!!

 

[knoober]

So then is this link not a viable product and just marketing madness?