Inflow/Outflow

[Sphexi]

I've got a TT Lanfire case, one of the mid-towers. Came stock with a few fans, I added one of those harddrive coolers and a PCI slot exhaust under my video card (X800XT). Recently one of the fans in the harddrive cooler (3 small fans) went, after less than a year of usage. Started doing the whole speed up, slow down thing. Then, one of the smaller (60mm) side fans that came stock went, doing the same thing.

I opened up the case and unhooked both from power, shut it up again, and not only does it run quieter (obviously), but it runs COOLER. CPU temp dropped a bit, as did overall case temp. Only thing I can figure is that there was an imbalance in how much air was being pulled in and pushed out of the case.

How do you decide exactly how many fans to pull in, and how many to push out? Do you simply have them all push out and let air flow in through open holes in the case?

 

[RallyMaster]

I looked quite a few things. First, I know that I will have one 80 mm intake that's closer to the PSU fan than the CPU heatsink. Second, I see that I have two 120 mm fans, one in the front for intake, one in the back as exhaust. Third: I plan on acquiring an Arctic Cooling Silencer NV5 to keep air flowing from front to back as well as a Freezer 64 Pro which will also reinforce my front to back approach. The 80 mm that was mentioned provides air at full speed to a slow moving 120 mm fan in the PSU. The front intake will provide instant cooling to my Seagate hard drive and will push air to the back of the case, allowing the Silencer to feed from that air and push heat from the video card out the back of the case. The 120 mm would take heat pushed back by the Freezer 64 Pro and exhaust it out directly.

Moral of my plans: Balance and quietness. I know that I have negative air pressure (more exhaust than intake), but my temperatures are low enough (even with stock CPU and GPU sinks). Speaking of which, I should really order that Silencer since my intake 120mm is pushing hot air exhausted by the video card back to the video card fan. Hmm...not good.

 

[imported_Sincity]

More out than in. That is also the reference AMD thermal design.

 

[LOUISSSSS]

is it ok if my case has holes all around the fronts and backs and bottom, if i have all my fans as exhaust or all as intake? what would be the difference?

 

[Howard]

More in than out gets you a cleaner case if you have intake filtration.

 

[RallyMaster]

It wouldn't be too wise to have all cases as intake because even though you're replenishing the case with cool air from outside, where would the warm air go? Unless the top of your case is a complete mesh, I wouldn't do all intake.

As for all exhaust, where would the case get the cool air? You're sucking air out but it's creating a slight vacuum in the process.

 

[Howard]

I never mentioned that the ideal ventilation was entirely intake, if you were referring to me.

 

[RallyMaster]

No, I was referring to Louisssss

 

[LOUISSSSS]

ic, but my entire bottom, front and back is mesh, so would any of the "entire intake" or "entire exhaust" solutions work? thanks

 

[Sphexi]

Well, something changed between when I last posted and yesterday. Came home and the box was totally locked up, not Windows but the mobo itself, reset button wouldn't even work, had to yank power physically.

Now it's running much hotter than it was, case temp is up around 95F, even though the other day it wasn't even close to that. Not sure what changed, but now my primary IDE channel doesn't work (DVD stopped being recognized, switched to secondary channel and it works fine), and it seems that the Southbridge chip (ACPI) is running pretty hot, at least according to SpeedFan.

I'm gonna order a few new fans, clean it all out and see how it works, I've been planning on switching to a nice new CM Stacker anyways, now may be the time to do so.