Joining two fans together?

paradisiac · 4 Jul 2011 at 16:34

would you get better or worse airflow if you joined to fans together?
i originally thought better as 2 fans blowing would shift more air, but then i thought, if the blades are not exactly the same place, then the front blade would stop the air the rear blade was pushing. and then i thought, damn i have confused myself so lets ask some clever people.

Judgeneo · 4 Jul 2011 at 16:36

Try it, note results.

One thing I can tell you for certain though is that its far noisier than having two independent fans

paradisiac · 4 Jul 2011 at 16:38

Judgeneo said:
Try it, note results.

One thing I can tell you for certain though is that its far noisier than having two independent fans

will give it a go tomorrow when i get my other fans (unless i can find a spare one in my pile of junk tonight). just thought, until i can get my cooler, if these shift more air then maybe it will help. or is there such a thing as getting too much air moving too quickly it doesnt have time to cool?

Kreeeee · 4 Jul 2011 at 16:43

It creates eddy currents iirc and doesn't work well at all.

Judgeneo · 4 Jul 2011 at 16:45

paradisiac said:
will give it a go tomorrow when i get my other fans (unless i can find a spare one in my pile of junk tonight). just thought, until i can get my cooler, if these shift more air then maybe it will help. or is there such a thing as getting too much air moving too quickly it doesnt have time to cool?

Nope, more air speed means a higher volume of air is hitting the cooler every second, so more particle collision, which means more heat exchange.

The only problem with two fans I can think of is the turbulence generated by each will interfere. Thinking about it now, you will probably get better cooling, but not twice as good.

Thinking further, a push/pull configuration works very well (where you have one fan blowing in on one side, and one blowing out on the other), the cooler 'smooths' the air somewhat then

paradisiac · 4 Jul 2011 at 16:45

Kreeeee said:
It creates eddy currents iirc and doesn't work well at all.

that sounds technical :confused:

just so i have this clear, it would actually do any harm will it, as its just air being moved around.

paradisiac · 4 Jul 2011 at 16:48

Judgeneo said:
Nope, more air speed means a higher volume of air is hitting the cooler every second, so more particle collision, which means more heat exchange.

The only problem with two fans I can think of is the turbulence generated by each will interfere. Thinking about it now, you will probably get better cooling, but not twice as good.

Thinking further, a push/pull configuration works very well (where you have one fan blowing in on one side, and one blowing out on the other), the cooler 'smooths' the air somewhat then

yeh, my cooler is rubbish and wont let m change/add fans to it, so i was thinking 2x120mm fans joined on the side blowing in (on the gfx cards and the cpu cooler) and 2x120mm fans joined blowing out of the rear. i then have a 200mm fan blowing out the top of the case and the rubbish cpu cooler fan i dont know which way the air is going

paradisiac · 4 Jul 2011 at 17:03

would i be better off turning the top fan around so its blowing air onto the heatsink, but then that would only leave the gfx cards, psu and rear fans as exhausts.

PhillyDee · 4 Jul 2011 at 18:02

Looks like there is more than enough airflow in that case to be honest. Can you change the orientation of the CPU cooler? Having it blow right to left with the rear fan exhausting might help.

scrlk · 4 Jul 2011 at 18:05

Problem solved.

paradisiac · 4 Jul 2011 at 18:08

PhillyDee said:
Looks like there is more than enough airflow in that case to be honest. Can you change the orientation of the CPU cooler? Having it blow right to left with the rear fan exhausting might help.

i dont think it fitted the other way around

does the fan blow or suck on the cpu cooler?

arknor · 4 Jul 2011 at 18:33

Vinni3 @H|H said:
Problem solved.

they arent even computer fans though they are those bathroom extractor fans that are only suposed to be run for a few minutes at a time not prolonged use

PhillyDee · 4 Jul 2011 at 19:04

Actually, its a delta, meant for extreme airflow where noise is not an issue. Usually used in idustrial machinery.

paradisiac · 4 Jul 2011 at 19:07

well i didnt have any spare fans, so i took the side fan off and stuck it to the rear exhaust fan.
original setup
MB 33c
CPU idle 39c
CPU underload 83c

new setup
MB 30c
CPU idle 40c
CPU underload 80c

new setup but with top fan as intake not exhaust
MB 35c
CPU idle 39c
CPU underload 86c (then i stopped)

so in conclusion it has possibly helped, or maybe the side intake was a hinderant. will find out tomorrow my my 3 new fans turn up.

munz · 4 Jul 2011 at 19:14

well heat rises so i guess top fan is best as exhaust

nice info though thanks for testing it out and showing us results

paradisiac · 4 Jul 2011 at 19:37

yeh, unfortunatly temps are 4c hotter in the house than normal

hate the warm weather. getting 3x120mm 2400rpm fans tomorrow so will experiment with them too.

OLDPHART · 4 Jul 2011 at 19:46

PhillyDee said:
Actually, its a delta, meant for extreme airflow where noise is not an issue. Usually used in idustrial machinery.

LOL, like the the old twenty films with the big wind machines.

paradisiac · 6 Jul 2011 at 08:51

fitted the new fans. is a bit annoying as the weather keeps getting hotter so its hard to directly compare, but today we are 24c (was 22c last check) and mobo is no 28c (best i had was 30c) cpu idle temps are now 34-37c but underload they still hit 80+c so although the extra fans are keeping the inside of my case cooler, i think the freezer 7 just cant keep thos cpu temps down