Putting a filter on a fan. Which side?

[VBboy]

Hello, guys.

This seemed technical enough to post it here. I would like to put a filter (mesh-type or something) on a case fan (like a regular 80mm fan). Which side do I put the filter on, on the "front" side that sucks the air in, or the "back" side that exhaust the air?

Basically, I want to preserve as much air flow as possible (as the filter would obviously restrict it). Would it be easier for the fan to push air through the filter once it "grabbed" the air (i.e. when the filter on on the back side)?

<===air===[FILTER][FAN BODY]<===air===

or like this:

<===air===[FAN BODY][FILTER]<===air===

Thanks in advance! And I promise to study physics next time!

 

[blahblah99]

neither.

 

[VBboy]

blahblah99,

Wow, ok. By the word "neither" that was not difficult to locate in your reply, do you mean that both fan/filter combinations would perform equally?

 

[capybara]

if you wanna use a filter. put it on the outside of any intake fans. exhaust fans
should not get any filter.

 

[L3]

Based on my experience (primarily mainframe) the filter should be on the input side of an input fan. Filters with a bit of dust are actually more efficient, up to a point. I agree that you don't want to filter the exhaust fan, get the stuff out, if possible.

 

[VBboy]

No, guys, I don't have a filter on the exhaust fans. I'm talking about which side of the intake fan to put the filter on. Essentially, I'm asking which side of the "window" to put the screen on

 

[Jeff7]

What L3 said is probably right; usually the filter goes over the intake side of a fan, so that the fan is pulling the air through the filter, not pushing it.
Blahblah99 was probably saying neither because filters do restrict airflow; that was probably an attempt at saying "don't use filters." Only do that if you enjoy vacuuming the inside of your computer from time to time. Ironically, dust on heatsinks will also affect cooling.

 

[SouthernBred]

I did the following, going from "outside" to "inside"

grill, filter, window, fan.

 

[whitelight]

put the filter on the outside. so air flows through the filter before going through the fan.

 

[astro]

A vote for putting the filter on the outside so air gets sucked through it. Keeps the fan itself clean too