should the fan on the side of the case by sucking air in or blowing it out?

[ssgohan434]

it is on the exact middle of the case. should it be blowing or sucking in? i have one intake in the front. this fan on the side of case is outtake, and one more slow outtake in the back under psu.

http://svc.com/ra32almidtoc.html

that is where the side fan is positioned on my case. cases are almost same except for color.

[mateo]

I would venture a guess and say blow...otherwise, it might deny the front intake air from the CPU area (perhaps?).

Since it's easy, best way to do it is try both ways and see which gives lower temps.

[nerdlogic]

I say try it both ways and see what kind of temps you get. The best way of finding things like that out is to experiment yourself and see what yields you better temps.

[chasingapple]

On my wifes computer she only has a 60mm outtake in the back of the case so I have her side fan blowing out for extra exhaust...and only 1 80mm intake.

[juliendogg]

it's allways good to have slightly more air (rated cfm's) coming into the case than leaving, this way you keep slightly positive air pressure inside the case, makes for nicer airflow and prevents dust from being sucked in through all the cracks. generally i'd think a fan in the side would do better as an intake, supplying cool air to the cpu and the gpu at the same time.


cheers,

J.

[eaglescouter]

Both of my PC's have side fans which are intake fans, and they blow fresh air onto my video card. They were preinstalled by Antec and Chieftec.

[OrionRU]

Have it blowing out, temps are lower by 1-2°C

Also intake for the side fan might distrub the airflow through the case ( might depend on your wiring, mines are to the side).

I.e. Mixing air from this fan, Vid card fan and CPU fan will create turbulance as in all of them are coming from diff direction.

I

[ssgohan434]

changed it to intake an temps are lower now

[adelphia83]

In most cases having an intake fan for the side will produce better results...

For example if you have your intake fans in the front, and an exhaust fan in the side and rear: A lot of the colder intake air will go right out the side of the case, without blowing out any HOT air.

In most cases the side fan is placed in the center of the side panel (more toward the front), it will not aide in cooling hot components (CPU, GPU, etc), if it is used as an exhaust fan. All it does in this situation is route the cold air that is coming in, out of the side.

By mounting it as an intake, it will blow cold air in from the side, right into the path of other oncoming intake air (from the front) where it will pass through the area of the CPU and other hot components, and will exit out the rear.

Yes this setup does add some extra turbulence (and as a result less airflow), but so does configuring the side fan as an exhaust.

I read several reviews on fan configurations (tomshardware.com was one of them), and they all seemed to come to the conclusion that side and top mounted fans (found on many cases today) are better set up as intakes.

[timmyqwest]

I also assumed the side fan was for your GPU, thus blowing in is a good thing

[V8gent]

equal to slight negative case is preferable in all cases (pun intended :D) I don't know why so many people think positive pressure is better. please read this (http://forum.oc-forums.com/vb/showthread.php?s=&threadid=192605) entire thread for more info.


EDIT: fixed typos

[OrionRU]

And you get less dust :D :)

V8agent is right

[adelphia83]

This thread became a sticky for a reason; Good advice on how to set up an effective cooling system whether it be the case, CPU, etc

http://forum.oc-forums.com/vb/showthread.php?s=&threadid=70679

[V8gent]

the article is good for the most but the point about positive case pressure is incorrect. postive pressure might help reduce dust build-up (with un-filtered cases) but .. is NOT the most effective way to minimise case air temps. it is a major misconception that positive case pressure is better.

can the sticky be changed perhaps?

[adelphia83]

Could you provide a link for your source of information?

[Epox]

it should be in your face, sucking air out, so you can't talk.

[Since87]

Yes V8gent,

How about backing your statement up with a scientific explanation.

What possible benefit can there be to having lower air pressure in the case?

[adelphia83]

It seems the only consensus is that a positive air pressure will allow "hot-spots" or areas of no air movement inside the case.

As was mentioned in the sticky-- I invite people to test this theory by using a lit cigarette or incense near each of the intakes and see exactly what happens. It seems that it would be apparent if any of these "hot-spots" existed by using this method.

Also that is a great method of testing the airflow in general inside the case. The faster it gets purged, the better. Also better if the air movement is past hot areas (cpu,gpu) to get rid of the hot air.

I tried it today but since I can't smoke inside the house (damn you roomates :-), I had to make do with what I had... melting wires by shorting a NiCD battery... Couldn't produce enough smoke...

Someone try it and let us know if this test is worthwhile

[WuChild]

Well one benefit would be that hot air in the case is a bad thing, and many times positive preassure just keeps the hot air in.

Remember that fans were *just* fans UNTIL Spangler invented the Vacuum, which is really the only TRUE way of moving air from one place to another.

So in either case, you are not going to be creating much of a positive OR negatively charged environment without equipment specifically designed to create a vacuum or a positively preassurised environment.

What you need to promote however, is decent airflow, to get that hot air out of the case, which is best done, by forcing air upon another fan which then blows it out.

[Since87]

Originally posted by adelphia83

I tried it today but since I can't smoke inside the house (damn you roomates :-), I had to make do with what I had... melting wires by shorting a NiCD battery... Couldn't produce enough smoke...



ROFL

Burning insulation and a NiCD blowing up and spraying Cadmium around the room. So much better than cigarette smoke. :D

[V8gent]

I've done some work in the design of large server rooms as a result of a background in liquid thermo-dynamics. air behaves the same way as liquid when thermal elements come into play. I understand it's not enough for most of you for me just to say it's so and expect everyone to beleive it. sorry about not providing linkage.

I've already linked to this (http://forum.oc-forums.com/vb/showthread.php?s=&threadid=192605) thread a number of times. it's a thread in which I explain why negative case pressure is better.

server cases and proper server rooms employ negative case pressure setups. the pro's have known that negative internal case pressure is best for years.

here some more info (taken from ProCooling (http://www.procooling.com/articles/html/5_myths_about_cooling__-_phaes.php)))

Positive case pressure (more intake than exhaust) is good for PC cooling.

This will be the most unpopular statement that I make: most of the noise and air produced by highly modified fan-heavy systems is purely for show.

Many serious server cases operate with negative pressure, and most of the major OEMs have sold cases for years (some for decades) with no intake fans. AMD's design specs call for ONLY an exhaust fan in the rear of the case and an ATX 2.03 spec PSU (fan pulling air from case on bottom and through the power supply). Sure, the intake fans on Antecs and Lian Lis will keep hard drives cooler than a case with no airflow over the drives. Are they actually improving the circulation of air through the case as a whole though? Or are they disrupting the exhaust fan's ability to pull air through the system? Without a smoke test it is hard to say for sure, but I tend to trust Liteon, Chenbro, Palo Alto, and many other seasoned manufacturers of high end workstation and server cases more than I trust someone with a holesaw, a box of fans, and a garage. There are other methods to directing airflow where needed besides massive CFM and noise. Many cases have louvres in the side panels that are designed to allow cool air to enter the case and be pulled across the hot CPU and then out the exhaust. Intake fans can disrupt this design and may actually hurt CPU temps. Dell servers and workstations often have elaborate ducting to pull heat from the CPU out the exhaust, but still operate sans intake fans.

The typical rationale for positive pressure in cases is that it protects cd-roms from dust build-up. This seems to be"a good thing", but can be pretty easily picked apart. Plextor cd burners have shipped with exhaust fans for years. These fans keep the inside of the drives cool by pulling outside air in and through the cd-rw. This is the worst case scenario for positive pressure, but Plextors are among the most reliable of optical drives.




EDIT: fixed typos.