Fan- Front of case or rear?

[JEDI]

i have a mid-tower. THe power supply blows air out.

since i already have something blowing hot air out, i'm thinking i should install a fan in the front to blow cool air into the case.

Right? If not, why?

edit: i only have 1 extra fan. my case comes with a side fan. my powersupply has 2 fans..1 on the bottom of the ps, and 1 in the back to exhaust out.

so where should i put it based on my scenario? back of case to exhaust hot air out or front to push cool air in?

 

[akira34]

have a fan pulling air in and at least one more venting out. The PSU fan alone isn't enough to do the job.

 

[Subhuman25]

If anything you should have an exhaust fan to compliment the PSU fan.Intake fans improve upon ambient air intake,but intake will occur regardless of an intake fan being present.Computer cases are not airtight.
Example: My Antec 3700BQE came with a single 120mm exhaust fan.Add to that my Antec NeoPower PSU with another 120mm exaust fan.Everything was ok cooling wise.I still added another 120mm intake fan just to improve things a little and it did.But not a huge improvement.I wasn't disappointed though because I wasn't expecting it to make a huge difference and the tradeoff for noise was negligable plus I gained some HD cooling for my single Seagate 200GB.
In fact I think I'm running quieter now with the added Antec Pro dual BB 120mm fans in my case as opposed to the single Antec casefan that came with the case.
I replaced the stock HSF with an Arctic Cooling NV Silencer5 on my eVGA 6800GT and also replaced the stock AMD64 3500 HSF with a Zantac 7000a AlCu.
My ambient case temps are in the low 20's,CPU temp in the 40-50's depending on load and the 6800GT in the 50-60's depending on load.
I'm very happy about my choices because cooling is great and the silence is also a very welcome benefit.
One thing to make note of is that if your intake grille doesn't sport a filter and you add an intake fan,you'll be collecting lot's more dust inside requiring more frequent cleaning of the innards of your case.
If indeed you are "front fan filterless" then positioning your computer case on the desk or somehow elevated off the floor will lessen dust being sucked in although moise levels will be more apparent because it's sitting closer to you.
Sorry for babbling your ears off

 

[Navid]

If you have one case fan, you will get the most out of it if you install it at the top rear (under the PSU) as an exhaust fan).
An intake fan will not increase the air flow as much since it is in series with the exhaust fans (The same air is moved by both fans).
Adding more exhaust fans will increae the air flow since the exhaust fans are in parallel (each additional fan adds to the amount of air moved through the case).

 

[MaskedAvenger]

Do both. Try some of the Thermaltake Silent Cat fans for quiet, high performance goodness!

 

[akira34]

Vantec stealth fans are a lot quieter than the Tt fans I've seen/used.

 

[effee]

Try the tornado fans if you dont mind the noise and want a powerful one

 

[Subhuman25]

Originally posted by: Navid
If you have one case fan, you will get the most out of it if you install it at the top rear (under the PSU) as an exhaust fan).
An intake fan will not increase the air flow as much since it is in series with the exhaust fans (The same air is moved by both fans).
Adding more exhaust fans will increae the air flow since the exhaust fans are in parallel (each additional fan adds to the amount of air moved through the case).

True this is,however by adding an intake fan you control WHERE the air enters the case from.In my case the front fan dictates where the air is drawn in from and towards,namely my HD.
With merely exhaust fans operating the intake air would come from any crack/crevice in the case and you wouldn't likely see any benefits or unnoticable benefits.