HSF direction

Solari

Solari

Solari

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Joined
14 Nov 2002
Posts
5,555
Location
Kent
Hi chaps,

I've had conflicting comments on whether my HSF is the wrong way round. Could someone please settle this?

Basically... 1 fan sucks in air at the front, an exhaust blows out the back. The HSF fan is blowing out towards the exhaust fan. I don't know the physics behind this if the fans are at different RPM/shifting different amounts of air and whether this is good or not.

There's a vent at the top of the case so I was wondering whether I should have the HSF fan blowing air upwards instead? :confused: I think this would not really help as the PSU would then be sucking in warm air... Case is a Lian Li PC-something-or-other.

Code: 
         _______....______
        |     |           |
       <- PSU |           |
        |_____|           |
        |                 |
        :   ||====        |
120mm  <- <-||==== HSF    |
        :   ||====        |
        |   	          |
        |                 |
        |=========        :
      <-:GPU            <- <- 120mm
        |_________________:
 
Rear, unless you have something along the lines of an antec x00 or coolermaster x90 etc with fans in the top.

In my 300, the only option with my TRUE was to point it upwards through the 140mm exhaust fan. This does mean it can be pulling warm air off the top of the GPU though.
 
Thanks :) There's no fan in the top, just vent holes. I didn't bother fitting one as I assumed any hot air there wouldn't need help escaping. Saying that it might draw more cold air up over the CPU but 2 exhaust fans and 1 intake fan doesn't seem balanced?

The only thing that makes me a bit confused is that there is about 1cm gap between the fan on the heatsink and the fan mounted to the back of the case... that makes me think that it probably can't be that efficient? Air forced onto a fan must result in some deflection back into the case? :)
 
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Admiral Huddy said:
As long as they are blowing air the same direction then it isn't a problem. The idea is to get the warm air out of the case as quick as possible.
Click to expand...

Cheers Huddy, appreciated :) I've seen a few pages on the net with the fan the other side of the HSF but I assume that they are trying to push air through the heatsink rather than "pulling".
 
Most people have Fan-HS-Space-fan-rear grill-outside (inside to outside)
you seam to have HS-Fan-gap-Fan-rear grill-outside

Not ideal but if fans pointing in same direction it's not 'wrong'

As you say two different fans next to each other causes turblence = reduced airflow and more noise.

Whats the HSF? can you leave the HS installed and swap the fan to the other side but keep it blowing to the rear of the case.
 
It's an Arctic Freezer7 Pro. Not sure if I can get at it to swap the fan position around but doesn't a "pushing" fan generate more noise than a "sucking" fan?

I'll have a look later on as I can't be bothered pulling the rig apart unless I'm doing a major upgrade :p
 
If it's an AC freezer pro you got it round the wrong way. the fan blows through the HS

ac_freezer64pro_install.jpg

Random google image but it shows what needs doing.
 
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I'm sure I turned the PC on and felt the fan blowing outwards :confused: That's why I mounted it the way it was... Paranoid now so I'll have to check tomorrow when I get some time.
 
It 'should' be blowing air through the HS - all open sided fans move air in almost every direction - but the focus is forwards through the HS.

Had one myself (as have at least 50% of the users here) swap it round and watch the temp and noise level drop :D
Don't worry about it - we all get it wrong once in a while.
 
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Set it up to push, that way the exhaust fan will act to some extent as a pull and should give a smoother airflow from fan, through the heatsink and out.

Also, try to match the airflow of the fans. You want, if possible, the exhaust fan pulling slightly more air than the HSF fan pushes. It's hard to be accurate, however, unless you have a fan utility of some sort.
 
OK chaps, I'll double check as I was convinced the fan was sucking air through the HS and hence blowing out towards the exhaust. That image above is blocked as I'm at work. Funny thing is my temps are alright :)

Hopefully I can swap it without having to pull the whole lot out of the case.
 
Ease said:
To be honest, if your temps are good who cares? :p
Click to expand...

Well it's been like this for about a year or so.. I think the highest I've had the CPU temp in TAT is 60*C - that was in summer with a moderate overclock. At the moment load is about 49/50*C.

Lower temps would obviously be a bonus so I'll still look into it :D
 
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shadowscotland said:
If it's an AC freezer pro you got it round the wrong way. the fan blows through the HS

ac_freezer64pro_install.jpg

Random google image but it shows what needs doing.
Click to expand...

Oh titties. Now I can see that (I'm back home), I see epic failure :p

Hum I'll order some cleaning stuff and TC and see if I can swap it at the weekend. No way can I get away with doing this in the case as the socket on my mobo is quite close to the back of the case and I can't get my hands in comfortably :(
 
Its not so bad easy enough to swap round :) ........ according to your diagram way up there though your fan was pulling air through the heatsink did you also swap the fan around or did you get the direction wrong in your diagram ? :)
 
mollymoo said:
Its not so bad easy enough to swap round :) ........ according to your diagram way up there though your fan was pulling air through the heatsink did you also swap the fan around or did you get the direction wrong in your diagram ? :)
Click to expand...

I was sure the fan was pushing air towards the back.. I'll check when I have a few mins. Seriously, it's quite cramped in my case and I can't see it being too simple to swap around - it's a mobo out job so I might just wait until I get another CPU (probably after payday) :)
 
Unless your top fan is directly above your hsf, I would go rear and have your top fan blowing out, but on a low setting so to just remove trapped air but not create a seperate flow that could possible disrupt your front to back air flow.
 
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