Do computer fans Stack?

[Edgar R. Zakarian]

I wonder, How much would it improve airflow if you add 3-4 fans for example?

 

 

For example, If you have a fan at the bottom of the case, which is too far away to feed the gpu with fresh airflow.

Would it help to 4-stack fans at the bottom of the cooler, to push a JET of air into the gpu ?

[Denned]

I bet it would be pretty much nothing. The option I would go with in that case, would be either a fan duct or Silverstone Air Penetrators (channeled airflow)

[slightlyjaded]

Check OC3d. Tom did one of these that was more than  a little psychotic if you want to check it out.

[Praesi]

Air is never too far away if its inside the case.

[Edgar R. Zakarian]

it's because my hd 6990 has gotten around 5-10° hotter being in my dark base pro 900 than it was in the aerocool x-strike GT case.

 

Only difference is, that the case is bigger, and the side-panel fans are gone. (Glass side on the new case)

 

So since it's getting air from a bottom fan, in the case, why is it getting hotter than before?? (same components, only case was changed).

[TidaLWaveZ]

9 minutes ago, slightlyjaded said:

Check OC3d. Tom did one of these that was more than  a little psychotic if you want to check it out.

That was actually a joke, there's a short disclaimer at the end that explains that the whole video was a joke and that the temps aren't real.

[G27Racer_188]

4 minutes ago, Edgar R. Zakarian said:

it's because my hd 6990 has gotten around 5-10° hotter being in my dark base pro 900 than it was in the aerocool x-strike GT case.

 

Only difference is, that the case is bigger, and the side-panel fans are gone. (Glass side on the new case)

 

So since it's getting air from a bottom fan, in the case, why is it getting hotter than before?? (same components, only case was changed).

Temp increase is probably cause by overall different airflow in the case, not just one fan being too far away.

[slightlyjaded]

Just now, TidaLWaveZ said:

That was actually a joke, there's a short disclaimer at the end that explains that the whole video was a joke and that the temps aren't real.

persoanlly figured the whole thing was a joke... fun to watch though.

[TidaLWaveZ]

1 minute ago, slightlyjaded said:

persoanlly figured the whole thing was a joke... fun to watch though.

I thought it was real for a long time and even looked into making something like that myself. I didn't even realize it was a joke until I saw some youtube comments that pointed out that Tom admitted he was joking at the very end of the video.

[ImBleu]

It won't work based on air dynamics. The fans will have too much resistance against dirty air which will wear out the bearings. If stacking fans worked, more people would do it. The only exception to this rule is with radiators etc in the way.

 

You'll notice an increase in sound and power (minimal) but no performance increase. Because you're dealing with a confined space (a case that isn't going to be over a couple cubic liters) the fan being next to the card or 5'' away really wont make any difference. 

[TidaLWaveZ]

Stacking fans does not increase total airflow, you'll be limited to the max airflow of one of the fan.

 

For example if you have two fans and they each have a max of 75cfm, stacking them will only give you 75cfm.

[slightlyjaded]

stacking fans works, it just doesn't work this way. as above said, the amount of dirty air (turbulence) with a bunch of fans that aren't synchronised just doesn't work. building a turbine engine however does. (basically a jet engine focusing wind down a narrow path)

[Edgar R. Zakarian]

22 minutes ago, G27Racer_188 said:

Temp increase is probably cause by overall different airflow in the case, not just one fan being too far away.

prior case fans:
2x 120mm front (in)
2x 120mm side panel (in)

2x 120mm up (out)

1x 120mm rear (out)

 

New case fans:

2x 140mm front (in)

1x 140mm bottom (in)

1x 140mm rear (out)

1x 140mm 2x120mm up (out)

 

Wouldn't think the difference is that great? 5-10 degrees seems a lot

[LogicalDrm]

5 hours ago, Edgar R. Zakarian said:

 

Do note that pic has rads between fans. Much different end result than just having fans on fans. Though last couple of rads won't perform as well as few first ones just because air coming to them is warmer.

 

4 hours ago, Edgar R. Zakarian said:

Wouldn't think the difference is that great? 5-10 degrees seems a lot

5-10C meaning what? How much are load temps now? You could move GPU itself closer to fans (to some other PCIe slot) or get better fans.

[Mira Yurizaki]

Fans don't stack. Let's think about this for a moment.

 

It would be like if you pushed someone on a skateboard. Now you might think if you can push the person 10m/s, then maybe getting four of your friends who can push the person 10m/s can make the skateboarder be pushed to 50m/s. Except you're all imparting the same force and since 10m/s is the limit for all of you, you can't break that no matter how many people there are. You'd have to impart a larger force against the person to get them to move faster.

[corrado33]

2 hours ago, M.Yurizaki said:

Fans don't stack. Let's think about this for a moment.

 

It would be like if you pushed someone on a skateboard. Now you might think if you can push the person 10m/s, then maybe getting four of your friends who can push the person 10m/s can make the skateboarder be pushed to 50m/s. Except you're all imparting the same force and since 10m/s is the limit for all of you, you can't break that no matter how many people there are. You'd have to impart a larger force against the person to get them to move faster.

You know, I almost have to throw out a situation where this is possible. Say you have 4 friends (and you.) You are on a tiny skate board riding on top of a massive skateboard that your friend is riding. (Like a 30 foot long skateboard.) That friend (and therefore you) are being pushed by another friend going 10 m/s who is riding an even more massive skateboard who is being pushed by another friend. 

 

Stack that until you have five friends (and 4 skateboards.) The largest skateboard will only be moving 10 m/s, but the board on top of the largest board will be moving 20 m/s relative to the ground (but only 10 m/s relative to the largest skateboard,) etc etc etc. Of course, this is impossible in real life, but still fun to think about. 

[Mira Yurizaki]

3 minutes ago, corrado33 said:

You know, I almost have to throw out a situation where this is possible. Say you have 4 friends (and you.) You are on a tiny skate board riding on top of a massive skateboard that your friend is riding. (Like a 30 foot long skateboard.) That friend (and therefore you) are being pushed by another friend going 10 m/s who is riding an even more massive skateboard who is being pushed by another friend. 

 

Stack that until you have five friends (and 4 skateboards.) The largest skateboard will only be moving 10 m/s, but the board on top of the largest board will be moving 20 m/s relative to the ground (but only 10 m/s relative to the largest skateboard,) etc etc etc. Of course, this is impossible in real life, but still fun to think about. 

That'll work if the skateboard is generating its own force. If it's running on the initial push, your push will generate a reaction force against the skateboard that will essentially cancel it out.

[corrado33]

Just now, M.Yurizaki said:

That'll work if the skateboard is generating its own force. If it's running on the initial push, your push will generate a reaction force against the skateboard that will essentially cancel it out.

Yeah, that was the second situation I thought of. I'm thinking more of a RUNNING push, so a constant force enough to propel each skateboarder (and the other skateboarders and boards on top of that board) at a constant 10 m/s (since nothing is ideal, just enough force to overcome gravity (if it's not flat) and friction.) That's why the boards would have to be so big. 

 

You're thinking of person 1 shoves person 2-5, person 2 shoves people 3-5, 3 shoves 4-5, etc. Yeah, that wouldn't work (although it'd be fun to watch.)