Which way do Fans blow?

bcomatts

Member
I am about to upgrade and add some fans to my system and I was wondering how it worked. Fans like my CPU and Vid Card fan, do those blow toward the chip or do they take air away from the chip? I tried sticking my hand infront of the chips but I can't tell where the air is coming from.

Furthermore, cases that have fans mounted on walls or top, is that like an exhaust system or is it actually sucking air in? like so: http://lib.store.yahoo.net/lib/xoxide/clear5.jpg

And on a regular computer with only the fans from the psu, cpu, vid card, the air comes in from where? and then gets flushed out the psu right?

Thanks, just trying to understand the air flow before I go upgrade/add fans.
 

Verve

New Member
Fans will always blow toward the chip. Usually only case fans will blow outward, taking the air out of the tower.
 

diduknowthat

formerly liuliuboy
well if you look on the fan, there usually are arrows pointing at the way the fan spins and the way air gets blown.

On the computer on the link, I would guess that the two front fans are sucking, the one back is blowing out. The top is blowing out, and the two sides i'm not sure about.
 

Greggie Boy

New Member
Take for example my case: Aspire XNavigator...front fan sucking in, two rear fan blowing out, top exhaust, psu fans blowing out and large side fan blowing out. There is a big misconception that the side fan should be blowing"in" and some people change it because it will blow towards the cpu and "must be better"WRONG" The warm air has to be moved out,otherwise you're only moving warm air around. My cpu(Prescott) runs below 30c so go figure???
 

BrandonL

New Member
Another way to tell is to look at the fan and see where all the dust is collecting. The side that has the greater amount of dust on it can help you determind what way it spins. it's hard to explain but if u check it out you'll know what i mean.

if you happen to not have any dust on ur fans... well then idk lol
 

Yeti

VIP Member
Fans will always blow toward the chip. Usually only case fans will blow outward, taking the air out of the tower.
Usually, but not always.
Furthermore, cases that have fans mounted on walls or top, is that like an exhaust system or is it actually sucking air in?
Both, generally the setup is intake fans on the front/bottom and exhaust fans near the rear/top.
There is a big misconception that the side fan should be blowing"in" and some people change it because it will blow towards the cpu and "must be better"WRONG" The warm air has to be moved out,otherwise you're only moving warm air around. My cpu(Prescott) runs below 30c so go figure???
That's kind of a case by case situation. True, there are setups that will benefit from an exhaust side fan, but the opposite is also true.
 

BrandonL

New Member
I remember what you said about putting your hand in front of the fan to see which way the wind was going. If you couldn't feel the wind then either it's going into the computer or the fan is too slow and you need to clean it
 

s_m_w_d

Member
why dont you check which way the fans are running in it now! its the easiest way I could think off!yeti is right the fans on the rear are in alot of cases blowing out air! what are you trying to change around
 

BrandonL

New Member
he doesn't want the fans to make noise and someone else was giving him suggestions on getting smaller fans or removing ones that could be replaced by pipes... i think you should thoroughly examine the fans to make sure that there is nothing hitting against it and making the sound... or..... maybe the fan was installed backwards... try turning it the other way
 

BrandonL

New Member
i still dont understand why they need to put 5 fans in the cpu... there must be some type of alternative
 

BrandonL

New Member
i give up lol. i have at least 2 black spinny things in my system and that's all im gonna say. they look like fans and they spin like fans so i think they're fans

what's the different between a fan and a fancase?
 

Yeti

VIP Member
what's the different between a fan and a fancase?
The "black spinny things" that are attached to your case are case fans - they bring in fresh air from and exhaust hot air to the air outside case. You'll also have a fan on your CPU heat sink (HSF) and possibly on your video card heat sink. The PSU will also generally have at least one fan exhausting. That's pretty much it for basic fans.
 
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