Top Blowhole...Intake or Exhaust??

[Codeman05]

Well I'm bored so I was thinking about putting in a blowhole in the top of my case. But I couldn't remember if it should blow into the case or out.
I've currently got 2 80mm intakes upfront and 2 80mm exhaust fans in the rear.
Thanks

Oh, and also...is there any program that can read GF4 gpu temps?? thx

 

[Mr. $T$]

Blow Out because the hot air is at the top of the case. Hot air rises, Cold air Sinks.


I do not think the gf4 has any kind of thermal reader in it.

 

[Codeman05]

ok cool thats what I was thinking
Thanks

 

[Tecumseh]

Not so fast. Try it both ways and check the results. Like Hoot
used to say forced circulation beats the natural tendency for
heat to rise. ----Not a direct quote, but close

 

[Jkasmann]

You might wanna consider positive vs. negative pressure also, since you currently seem to have about equal CFM intake and exhaust. Adding a top exhaust will give negative inside pressure and draw dust in. If i were you id add a side blowhole intake above the proc and a top exhaust (both with about the same CFM).

 

[DreamingWolf]

That or just turn your present exhaust fans around so that all down below are intake with the one blowhole in the top going out. (I found that having 4+some minis blowing in and only my PSU blowing out actually dropped the ambient temp in my rig about 3C compared to 2+minis in and 2+PSU out)

DWolf

 

[Codeman05]

Well, I just I'm going to try the side fan as soon as my Acrylic window sheet comes in, I don't feel like trying to cut glass hehe.
Now with a side fan blowing onto the cpu, would a top blowhole work better do you think??
Thanks!

 

[ziah]

heat rises!! i say exhaust.

~z

 

[Codeman05]

Well I just tried it blowing into the case and CPU temp dropped 3C (comparing before and after fan after running prime for an hour)...not sure how much the case dropped, I forgot to check before hand hehe. When my better fan comes in I'll try both ways to see which works out better.

 

[Fever]

Blowing in seems to give me better results.

 

[ziah]

interesting. guess it makes sense that there is more turbulence and airflow internaly. instead of just sucking a bit of heat out.

~z

 

[Robbie]

Exhaust. Remember heat rises.
Rob

 

[RedDeathDrinker]

Exhaust. What the others in support of exhaust have said

 

[Codeman05]

well reguardless of the fact that hot air rises, I get better temps with the fan blowing in...maybe has something to do with the airflow in my case. I think I've got enough air moving quick enough that it dosen't rise so much before its sucked out. But when I just in the side fan blowing on the CPU that might change things