woundering about something......does this make a diffrence?

LoneWolf · 08-14-2005, 12:41 AM

Heres a weird setup I got a buddy at work that showed me his computer he said that he

has two 80mms in the front and in the back glued together and he even has two 80mms

on his CPU and GPU just wondering do two fans really make a difference when rigged together like that?

Note: they are all high CFM fans

Dark_Sniper* · 08-14-2005, 03:18 AM

well if there mounted like one on tope of each other its just fanning 2 fans its pretty good more air comes in or out .

hercules_upw · 08-14-2005, 10:55 AM

I would say that there is no advantage gained by stacking fans.

Let me explain my logic.

If both fans are rated at the same CFM, the first fan is only going to push that volume of air.

The second fan can only push the volume of air supplied by the first fan, so the second fan is limited to the maximum volume that the first fan can push.

If your friend wants to make good use of the two fan set up, he should put the fans side by side. That would make them independent of each other and he would get a greater volume of airflow.....

FghtinIrshNvrDi · 08-14-2005, 12:39 PM

I disagree. Although I don't believe it offers a 100% increase in airflow from stacking, I think it is beneficial. Here's my logic.

When you stack the fans, they're helping each other by speeding the air up faster than what they're rated for. The CFM rating is only with one fan, operating alone, with no real resistance. Now when you stack them, I believe you're substantially increasing the pressure inside of the case and helping PUSH the air into there, and the exhaust fans will do the rest. I think it really gets some momentum behind your cooling.

Ryan

zynx23 · 08-14-2005, 05:47 PM

interesting..

SHAWN · 08-15-2005, 01:53 PM

Quote:

Originally posted by hercules_upw
I would say that there is no advantage gained by stacking fans.

Let me explain my logic.

If both fans are rated at the same CFM, the first fan is only going to push that volume of air.

The second fan can only push the volume of air supplied by the first fan, so the second fan is limited to the maximum volume that the first fan can push.

If your friend wants to make good use of the two fan set up, he should put the fans side by side. That would make them independent of each other and he would get a greater volume of airflow.....

I agree 100%.

sikyon · 08-15-2005, 07:22 PM

Stacking fans should only have a "marginal" benifit, unless they are relativly flat(not configured for full aerodynamic ability) and synched to spin together perfectly, in which case they become close to 2x as effective(because they are basically like a fan that has blades twice as thick). If they are not configured like this, it's basically a fan blowing with the wind. Which doesn't do anything because of the nature of how fans work(if you don't believe me, just visualize a particle of air moving with the direction of the spin, and track the position of the fan blade relative to the particle of air). Thus, the second fan will not actually do anything.

woot7800GT · 08-15-2005, 08:11 PM

Yeah... not too much I don't think. Except a helluva lotta noise.

08-14-2005, 12:41 AM	#1 (permalink)
LoneWolf Junior Techie Join Date: May 2005 Posts: 67	woundering about something......does this make a diffrence? Heres a weird setup I got a buddy at work that showed me his computer he said that he has two 80mms in the front and in the back glued together and he even has two 80mms on his CPU and GPU just wondering do two fans really make a difference when rigged together like that? Note: they are all high CFM fans

08-14-2005, 03:18 AM	#2 (permalink)
Dark_Sniper* Monster Techie Join Date: Feb 2005 Posts: 1,748	well if there mounted like one on tope of each other its just fanning 2 fans its pretty good more air comes in or out . __________________

08-14-2005, 10:55 AM	#3 (permalink)
hercules_upw Ultra Techie Join Date: Mar 2004 Posts: 691	I would say that there is no advantage gained by stacking fans. Let me explain my logic. If both fans are rated at the same CFM, the first fan is only going to push that volume of air. The second fan can only push the volume of air supplied by the first fan, so the second fan is limited to the maximum volume that the first fan can push. If your friend wants to make good use of the two fan set up, he should put the fans side by side. That would make them independent of each other and he would get a greater volume of airflow..... __________________ Lian Li Aluminum Case Intel D975XBXK2R Mobo Core 2 Duo E6700 CPU EVGA 8800 GTS Video Card Corsair XMS 2 x 1gig RAM Zalman 9500 CPU cooler

08-14-2005, 12:39 PM	#4 (permalink)
FghtinIrshNvrDi Wizard Techie Join Date: Jul 2005 Posts: 3,475	I disagree. Although I don't believe it offers a 100% increase in airflow from stacking, I think it is beneficial. Here's my logic. When you stack the fans, they're helping each other by speeding the air up faster than what they're rated for. The CFM rating is only with one fan, operating alone, with no real resistance. Now when you stack them, I believe you're substantially increasing the pressure inside of the case and helping PUSH the air into there, and the exhaust fans will do the rest. I think it really gets some momentum behind your cooling. Ryan __________________ I'm an unhyphenated American. System Specs: Intel Q6600 @ 3200 1.4v Abit IP35 Pro "The Snake" 2x2gb A-Data @ 800 Diamond HD 3870 512mb Great FORD TRUCK resource: http://www.fordtruckfanatics.com

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08-14-2005, 05:47 PM	#5 (permalink)
zynx23 Newb Techie Join Date: Aug 2005 Posts: 11	interesting..

08-15-2005, 07:22 PM	#7 (permalink)
sikyon Newb Techie Join Date: Aug 2005 Posts: 16	Stacking fans should only have a "marginal" benifit, unless they are relativly flat(not configured for full aerodynamic ability) and synched to spin together perfectly, in which case they become close to 2x as effective(because they are basically like a fan that has blades twice as thick). If they are not configured like this, it's basically a fan blowing with the wind. Which doesn't do anything because of the nature of how fans work(if you don't believe me, just visualize a particle of air moving with the direction of the spin, and track the position of the fan blade relative to the particle of air). Thus, the second fan will not actually do anything.

08-15-2005, 08:11 PM	#8 (permalink)
woot7800GT Monster Techie Join Date: Mar 2005 Posts: 1,261	Yeah... not too much I don't think. Except a helluva lotta noise.