Fan Placement and Airflow Direction

[CalebSchmerge]

I am about to add two 120MM fans to my case. I already have two in there, so I want to get some input on the placement of the others and what direction the new ones should move air.

The current fans are in a "standard" arrangement. One is in the front at the bottom of the case, bringing in air in front of the HDD cages. The other is in the back next to the I/O-Shield, sucking air out of the case.

I plan to put one of the new fans on the side air intake (supposed to be lined up above the CPU, but it isn't quite. I am thinking about punching a 4.5" hole in the top of the case to put the other fan (basically next to the PSU). If these are good places to put the fan, what direction should they move? If the top fan moves air in it can blow air straight into my CPU cooler and would flow in the same direction as my PSU. Then, should the side fan move air out of the case to help balance everything out? Should I have three intake fans and only one exhaust?

PS - all of the fans will be hooked up to a fan controller on their own channel, and mounted with rubber mounts for noise concerns. If you think there is a better place for the fans I'm open to ideas. Also, if this doesn't make sense I can come up with some pictures too.

Thanks!

[crash]

Well, the fan on the side should be blowing air out of the case since the CPU will be pushing air away from it.

As for the other one, I'm guessing you're out of fan holes? Is there space to mount another on in the front?

[CalebSchmerge]

Technically I am out of space. I have access to a 4.5" punch, however, so I am going to add a hole to the top of the case. The hole will be near the power supply. I am assuming what I will do, based on your comments, is make the top fan bring air into the case, then the side takes air out. I can put the cpu cooler so that it intakes air almost right from the top fan, then the side will suck out the exhaust pretty quickly. Does that sound like a good way to do this?

[crash]

Technically I am out of space. I have access to a 4.5" punch, however, so I am going to add a hole to the top of the case. The hole will be near the power supply. I am assuming what I will do, based on your comments, is make the top fan bring air into the case, then the side takes air out. I can put the cpu cooler so that it intakes air almost right from the top fan, then the side will suck out the exhaust pretty quickly. Does that sound like a good way to do this?

Since CPU coolers usually blow air perpendicular to the motherboard, it should be blowing it right to the side fan. So yes, having the side fan bring air out of the case would be best

And having a fan blow air from the top is a good idea as well. So basically,

Front: In
Top: In
Back: Out
Side: Out

[mtarm1]

sorry does the cpu fan blow on or away from the cpu?

[CalebSchmerge]

I'm using a tower cooler, so I can put it so the fan is blowing air from the top of the case toward the bottom of the case or the opposite of that. Its halfway lined up with the PSU intake and it will overlap the fan that I am going to install in a few hours. I'm starting to think that I'm better to intake from the side fan and exhaust out the top, that way I have all the air moving in one direction, instead of fans trying to work against each other.

[mtarm1]

also hot air rises...
so the top fan shoul be outtake...
wich means you would be correct in sayingside fan intake unless your cpu fan blows away from your mobo...

[crash]

Don't most CPU coolers blow air away from the CPU?

[Sprint]

most coolers (that have the fan the same way as the MB, not towers) blow the air onto the heatsink and out away over the MB. So the side fan is better off as a intake on that sort of coolers (or having a duckt to direct air to it)

[CalebSchmerge]

I'm using a tower cooler, so it blows air from the side. The new fan definitely helps the CPU temperature, but earlier my GPU temps were very high. I will monitor and see if those go back down.