View Full Version : What is the best air solution? Higher Intake, Higher Exhaust or Equalized?
jvandecar
02-23-2008, 10:59 PM
My hunch is Higher Intake, for over pressure but I dunno for sure. :shrug:
I've got a Lian Li PC-S80 case.
80MM Top Exhaust - Noctua NF-R8 - 31 CFM @ 17DBA
80MM/120MM Power Supply Exhaust - Enermax EG701AZ-VE(W) - Guessing 35ish CFM @ UNK DBA
120MM Rear Exhaust - Panaflo M1A - 86.5 CFM @ 35DBA
Video Card Exhaust - nVidia 8800 GTS 640 - Guessing 35-65 CFM
That's 187.50 - 217.50 CFM exhausting out the back of the case.
I only have two 48 CFM intake fan's.
120MM Front Top Intake - Noctua NF-S12 - 48 CFM @ 17 DBA
120MM Front Bottom Intake - Noctua NF-S12 - 48 CFM @ 17 DBA
That's only 96 CFM intaking.
Should I try and balance this out somehow?
perfection
02-24-2008, 01:28 AM
I'm still on the stock fans, aparently negative air pressure in the case helps cooling
I'm not overally concerned, as the airflow that comes into the case is fairly restrictive through the baffles so i would think negative pressure would help intake air
have you got pics of your PC, i'm interested in seeing it, haven't seen many Lian Li PC-S80 builds
STEvil
02-24-2008, 02:30 AM
Doesnt really matter as long as you've got enough moving through to keep the air inside from becoming saturated.
A bit more coming in than going out is what I like, keeps lots of dust from getting into cracks.
cabbspapp
02-24-2008, 02:40 AM
I honestly don't think the 8800GTS fan puts out nearly that much at max. Mine didn't move a lot when dialed up to max.
spookmineer
02-24-2008, 02:52 PM
No matter what setup you have, intake equals exhaust every time. You can't have "more air going in then out" (or vice versa).
Only difference is a slightly higher (or lower) pressure then ambient inside the case. The amount of air going in is the same as going out though.
LemniaAlsa
02-24-2008, 06:00 PM
How does having more intakes than exhausts decrease dust? Is it due to the increase pressure inside the case creating a vacuum outside the case?
Crazy Chuckster
02-25-2008, 10:17 AM
You can have more air going in than out, it just tends to find its way out of all the cracks and seams of the case.
I prefer that actually as I have seen that it tends to reduce dust in the case overall.
spookmineer
02-25-2008, 12:32 PM
You can have more air going in than out, it just tends to find its way out of all the cracks and seams of the case.
...So you can't... (your comment is contradictory)
You can't leave little cracks and seams out just because they aren't close to a fan.
Adding up the CFM of the exhaust fan and the CFM from all the little seams and cracks where air leaves the case, will be equal to the CFM of the intake fan (if there is one).
The "alternative" would be a case that at some time will be blown to pieces or a case which expands like a balloon under pressure :/
jcool
02-25-2008, 12:39 PM
Combine higher intake with a dust filter in front of every intake fan and you'll be completely dust-free. That's what I did with my rig and it works great.
jvandecar
02-25-2008, 02:42 PM
have you got pics of your PC, i'm interested in seeing it, haven't seen many Lian Li PC-S80 builds
On their way.
No matter what setup you have, intake equals exhaust every time. You can't have "more air going in then out" (or vice versa).
Only difference is a slightly higher (or lower) pressure then ambient inside the case. The amount of air going in is the same as going out though.
This sounds logical.
jvandecar
02-25-2008, 03:21 PM
http://img292.imageshack.us/img292/4648/img1251bq9.th.jpg (http://img292.imageshack.us/my.php?image=img1251bq9.jpg)http://img246.imageshack.us/img246/5376/img1248ih8.th.jpg (http://img246.imageshack.us/my.php?image=img1248ih8.jpg)
http://img146.imageshack.us/img146/332/img1238yb4.th.jpg (http://img146.imageshack.us/my.php?image=img1238yb4.jpg)http://img167.imageshack.us/img167/1733/img1233gi8.th.jpg (http://img167.imageshack.us/my.php?image=img1233gi8.jpg)
Third pic, is the E8400 installed on the 780i board I had to RMA.
STEvil
02-25-2008, 05:35 PM
No matter what setup you have, intake equals exhaust every time. You can't have "more air going in then out" (or vice versa).
Only difference is a slightly higher (or lower) pressure then ambient inside the case. The amount of air going in is the same as going out though.
Correct, however with less going in than out the dust will go in through the cracks.
With more going in the dust tends to take a more common path and not get into the cracks.