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maiof
09-04-01, 11:54 AM
is it better to have more air going in than out or more air going out than in?
ve6jhc
09-04-01, 12:26 PM
You need to match your intake fans CFM to your outgoing fans. If you have the same size/speed fans you will get the best airflow through your case.
Owenator
09-04-01, 03:35 PM
From what some of the more experienced members here have posted I got the impression that having about 20% more air out than in was good. That way cool air is always trying to get into your case. My case is almost at ambient, I have one 85 CFM 120 mm fan and one HD cooler wiht three 40mm fans in and five 80mm 24 cfm fans blowing out.

O
chawken
09-04-01, 03:42 PM
Originally posted by maiof
is it better to have more air going in than out or more air going out than in?

Positive pressure - about 15% - 20% is best. I have tried it both ways:
Room temp @ 21c

590cfm out - 500cfm in, negative pressure, case temp 24c
500cfm out - 590cfm in, positive pressure, case temp 21c
AlanSr
09-04-01, 04:51 PM
I've seen a 2C drop with a lil more going out.
KeyboardCowboy
09-04-01, 05:26 PM
i have found that a little more going in about 10-15% more cfm's usually works the best
Foppy
09-04-01, 10:23 PM
Originally posted by chawken


590cfm out - 500cfm in, negative pressure, case temp 24c
500cfm out - 590cfm in, positive pressure, case temp 21c

1090 CFM?! Is your case made of fans?
burn'em
09-05-01, 12:39 AM
As you can see from these post the best way is to try it both ways and see what works best for you. I think it has a lot to do with where the fan are and the air flow in the case. My case has negative pressure. Thats what works for me. I taped all the holes I could to keep the dust out.
SickBoy
09-05-01, 12:52 AM
I have an intake right over my HSF and when I switched to an SK6 this afternoon, I noticed my old HSF had grime all over it....

I guess the moral of the story (in addition to what people have been posting) is to try multiple different configurations on the case cooling. I tend to go slightly positive but I also have not played with it that much. I do know that I've got some filters coming with my next parts order (at least for the intake fans).

SickBoy