Fan Filter Airflow Compared

[Vapor]

Alright, have been meaning to test this since Round 1 of my fan testing, but kept forgetting/didn't want to do it when I remembered.

Well, been getting started on Round 3 of my fan testing and was reminded of this.

So I bought all the fan filters available from Petras and put them to the testbed. I have no explanation of any of the data yet, I usually put a day (or a couple months in the case of Round 2 fans) between testing and publishing to ponder/rest/graph/etc. This data is less than an hour old at the time of writing. And I expected almost none of it. This is my first time with a few of the fans too...so surprises all around!

All filters were tested in pull (since who puts fan filters on their exhaust?).

Fan selection was based on a desire to have:
1) A wide range of RPM overall
2) A variety of fans at similar RPM

I have no intention of doing a dust test...just no good and controlled way to do it Also, no ghetto stuff yet, maybe that'll come with time or when I figure out a dust test I like.

The fans:
AeroCool Turbine (950RPM)
Noctua P12 (1300RPM)
Yate Loon D12SL-12 (1350RPM)
Slip Stream M (1200RPM)
S-Flex G (1900RPM)
Panaflo U1C (2750RPM)

The Fan Filters:
"Wire Grille" - Click
"Metal Mesh" - Click
"Plastic Mesh" - Click
"Blue Thing" - Click
"MCR120" - Click

Pretty graphs:
All the airflow data:
see below

Airflow data of the ~50CFM fans (so it's easier to see)
see below

Airflow loss as a percentage, compared to open-air
see below


Words from me:
I have little explanation for why the wire grille is restricting airflow so much. In fact, I just included it as a control of sorts. I'm also very surprised that some of the filters are as restrictive or more restrictive than the radiator (depending on fan). The variance from fan to fan is also a bit of a puzzle.

I hate to hit it and quit it, but I have to run now. More from me later (tomorrow likely).

EDIT: redid all testing on a different testbed (the one I plan to use for Round 3 of my fan roundup) and no longer had any sort of airleak issues and now have much cleaner (and better, IMO) data. See below for new graphs.

[geisher]

Nice job Vapor. Good information, thanks a lot man .

[Ashraf]

Many thanks for this, Eric!

[TedShred]

Thanks for your efforts, Vapor. That's great info. What an eye-opener on the restirction by mere wire grills. You've removed any doubt I had about chopping out the meshed fan holes in my case.

edit: really gotta wonder about the flow from this TT1200W psu. Big fan, but the air has to go through slots cut into the psu and then the fan hole mesh.

[XtremeTiramisu]

Excellent review with professionally done comparason charts.
The metal mesh will be my best pick for the best dust filteration performance to least amount of air flow reduction ratio.

[Ar3s]

Totally confusing since my silverstone tj-09 casing metal mesh doesn't kill airflow that much & fan grills, now thats interesting.

[Vapor]

I'm redoing this on a different testbed...found out I was having problems with airleaks on at least the "Wire Grille" and the "Blue Thing". The results were repeatable (I ran each test twice since the numbers were looking funny and some even non-sensical), but looking back, that only really meant that the airleaks were repeatable and had repeatable impacts on measurement.

Testbed will also be the one for Roundup 3 (the box CyberDruid built), rather than the one from Roundups 1/2 (which I used two nights ago). Open air and radiator numbers (and metal mesh and plastic mesh even) shouldn't change outside of the margin of error.

[Vapor]

Oh, and my theory as to why the leaks effected the low pressure fans the least is because they simply didn't have the power to pull any significant amount of air through the leak. Still collecting more data on the new testbed, don't have much of a picture yet, so maybe the data is repeating itself, haven't done open-air numbers yet

[Vapor]

Yay for triple posting....

(don't worry guys, I'll go lower my post count )

Anyway, for the "Metal Mesh" filter...do people mount that on the outside or inside of the case?

That is:
1) FILTER | CASE PANEL | FAN
or
2) CASE PANEL | FILTER | FAN

I know how the rest get mounted, but this one seems to be able to go both ways, not sure which people do more.

[it_burns_when_i_pee]

i've been saying for a while how much grills can restrict airflow. you need only place your hand 6 inches infront of your face and blow, introducing the grill in between every now and then. its so noticeable

glad you got this up vapour. loads will benefit from it

[Vapor]

Okay, new data...doesn't say much different in the grand scheme of things, but I feel a lot better about it now.

[Tonucci]

I always wondered about how filters impact airflow...Thank you !

[XS_RoB]

Yes - a big thank you! Thanks for taking the time to be thorough and explaining your test methods! It is greatly appreciated.

[MpG]

Very interesting. Surprising that some of those metal meshs were less restrictive than the radiator, but go figure.

Also surprising about the respective fan performances of the 50cfm group. I assume those are Petra YL's? Based on other reviews I've seen (as well as personal experience) I would have expected the P-12's to edge ahead of the YL's and the Slipstream. And if I'm not mistaken, in one of your fan reviews, you mentioned that you wouldn't expect particularly good performance of the Slipstreams under restriction. Any ideas?

[Vapor]

Honestly, I was surprised to see any of the filters being more restrictive than the radiator. I've always just thought a radiator is the most restrictive thing you could throw at a fan

Yeah, that D12SL-12 is a PTS Yate. I expected the P12 to be better than it was as well--and the Slip Stream to be worse (well, a couple weeks ago I expected it to be worse--when I first received my fans, I put the Slip Stream SH up against the S-Flex G and realized the Slip Streams actually weren't so bad on a radiator for just raw airflow). The Slip Stream is easily the loudest of the three, however. Frankly, I have no explanation for the P12's performance. I'm shocked it performs poorly on the radiator--maybe it's just a bad pull fan? Will try push shortly I guess.

Then again, Petra's Yates are excellent radiator performers. They're almost competitive with 38mm thick Panaflos in terms of airflow loss--no easy feat. I didn't expect either the P12 or the Slip Stream to match it, but I certainly didn't expect the P12 to lag behind the Slip Stream. Oh well.

[Vapor]

Okay, retesting the three ~50CFM fans on the radiator now...Yate Loon and Slip Stream haven't changed at all, but the P12 is now doing 36.6CFM pull (26.7% loss) and 40.8CFM in push.

Moves it ahead of the Slip Stream @ 34.65CFM, but still behind the D12SL-12 @ 38.78CFM.

No clue why the P12 was bad (@ 33CFM) before--it doesn't seem to be a finicky fan and nothing has changed in my environment, not even temperature. No clue what happened

Graphs updated.

[Xel'Naga]

Vapor, it would be a lot better to group the graphs by the fans, not the filters, IMHO. We could see the results a lot better.
Like this:
Fan1(open)/Fan1(wire grill)/Fan1(some filter)------Fan2(open)/Fan2(wire grill)/Fan2(some filter)

Also I was really surprised by how much restriction a wire grill has. I was expecting almost the same performance as open gap

[Vapor]

Ask and ye shall receive:

All fans:


50CFM fans:


Percentage loss:

[Xel'Naga]

Ask and ye shall receive

Holy , you are fast

[64dragon]

Yay for triple posting....

(don't worry guys, I'll go lower my post count )

Anyway, for the "Metal Mesh" filter...do people mount that on the outside or inside of the case?

That is:
1) FILTER | CASE PANEL | FAN
or
2) CASE PANEL | FILTER | FAN

I know how the rest get mounted, but this one seems to be able to go both ways, not sure which people do more.

i use #1

thank you for you time and effort, these results are very good to know. i'd love to know how restrictive the mesh on my tj07 is or on a rad grill

[Vapor]

I figured most did #1 so that's what I tested with. They're probably both really similar...maybe even zero

[Ar3s]

slip stream doesn't like the plastic mesh but works great with metal and blue thingie... thats interesting. Always knew the Yate loons were awesome fans but this is mind blowing.

makes the p12 fan seem horrible for a push pull config on a cooler doesn't it ?

[[XC] NetburstXE]

Awesome work Vapor, thanks for the tests.

[dA_PhReAk]

Great Job! I was always curious how my "metal mash" would affect the airflow.

(And answering to your question: i use it on the outside of the case)

[zepper]

I thought fan restriction operated on the inverse square law, i.e. twice the distance - 1/4 the restriction.

Thanks for the test data. I've been using the 3-piece plastic on the basis that they would do better over time in a dusty environment, IOW they wouldn't clog up enough to affect performance as quickly as the other designs and would be more effective (how long until a noticeable buildup inside the machine - another aspect of filters available for testing ;-) . Also be aware that the plastic, 3-piece jobs can come with two different porosities of filter material (see the Mouser catalog).
. Perhaps when you get some time you could investigate the clogging rate aspect of filters, Vapor.

Here is a random datum for you: the metal "mesh" on the front of the fan holder in the Silverstone Kublai cases drops the fan RPM about 100. My "mesh" grows an intolerable skin of dust in a week or so. I don't mind that when I replace the "mesh" front with one of the plastic filters as it is supposed to collect dust...

.bh.