I will post this so you can get an email saying you have an answer. Then you will visit, see that your question was eaten, and ask it again. Then we can answer it for you 
I will post this so you can get an email saying you have an answer. Then you will visit, see that your question was eaten, and ask it again. Then we can answer it for you
I will also post twice, so that I can remember to get emails sent to me letting me know you have re-asked the question.
Yeah, that sounds like a good reason.
Server evidently swallowed the OP during the previous 45 minutes of “Cannot Find Page” crisis. :rolleyes:
Idiot hamster, doesn’t it know by now to get the prescription for dexies refilled before Walgreen’s closes? 
Manny, care to restate?
Well the question didn’t get eaten. I hit submit then the page timedo ut. My original question was
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I tried google but couldn’t find this.
I remember seeing on an overclocking site someone posted a way to make a filter at home to help reduce the amount of dust that fans blew into your system. I rememer they used the AC filters cut to size but I don’t know if it was put before the fan or after the fan
Example
(outside case)filter[inside case]
or
(outside case)fan[indside case]
Also what type of AC filter do you use?
And Mods if this somehow becomes a dupe please kill the dupe and not this one
It depends on your needs. Either will work.
You need a set path for air through the computer. An old Mac clone I have has an exhaust fan on the power supply and a tiny fan inside the case that blows at the processor’s heat sink. The power supply fan creates a negative pressure inside the case, so air has to get in somewhere. Since they didn’t design a vent for it to come in, it sucked air through the floppy drive and CD-ROM, making them the filters. Both drives died within a year.
Anyway, the point is that you need a place for air to get in the case and a place for air to get out of the case. You want to filter the air before it gets inside the case. You want the case at positive pressure so that the drives aren’t acting as air filters.
So, flow schematics. Air flows from left to right:
filter -> case -> fan -> through computer -> exhaust vent
or
filter -> fan -> case -> through computer -> exhaust vent
are the simplest and most efficient designs where the air filter is outside the case so that it can be easily changed.
If it already has an exhaust fan on the power supply, you’d want to go:
filter -> case -> fan -> through computer -> power supply fan -> exhaust vent
If your environment isn’t that dusty (then why are you bothering?) and you don’t mind needing to open the case to clean the filter, then go:
case -> filter -> fan -> through computer -> exhaust vent
Pretty intuitive, really.
Oh Jeez. I thought this was about Tech’s needing help with a computer fanatic.
Never mind…
I have the computer on a desk so it’s off the carpet. There is a fan on the bottom front sucking air in. There is a fan that I added in front of the drive cage blowing air oiver the drives. The drives a 4 7200rm drives that get very hot. Every few weeks I notice white ash like dust caked on the drives and the fan that I have to clean off. On the CPU I have two Fans (It’s a slot A athlon) Behund the CPU I have a case fan blowing air onto the CPU. Right above this fan is the Power Supply that is blowing warn air out. In the very top of the case I cut a hole and have a fan blowing air out. I’m tired of cleaning the dust off the drives and I know the dust is making them hotter.
A filter in front of the bottom front fan should do it, if that’s where all the air is going into the case.