So, what's the consensus on removing fan Grills?

mbx1 · Post by **mbx1** » Sun Jul 03, 2005 8:49 am

Good idea? Waste of time? I have an SLK3000B on order, and I'm going to be putting a pretty serious gaming rig in it - AMD +3800 and Nvidia 7800GTX, so airflow is pretty important.

I've seen pics that people of posted of their rigs that have the fan grills cut out, and it seems intuitively obvious that it would help airflow. On the other hand, 'a difference which makes no difference is no difference', and maybe it just won't be measurably cooler, or quieter.

All comments welcome.

Thanks,

-M

Tephras · Post by **Tephras** » Sun Jul 03, 2005 10:06 am

Since most people building quiet computers often run their case fans on low voltage the removal of fan grills will have a notable impact on airflow. It will also be beneficial for the overall noise level, even more so with fans running at a higher voltage. It's an easy thing to do and it wont hurt (unless you put your finger in the running fan

).

Lubb · Post by **Lubb** » Sun Jul 03, 2005 10:54 am

-Generally speaking, cut them out. It harms nothing, they are usually hidden from view (the fronts are behind the faceplate and the rears are out of view anyway), and it improves airflow. ....I bought a couple generic cases to use as donors and the "case fan grilles" as they came were a joke! They were holes maybe 1/16", drilled on a 1/4-inch square pattern. I put the PC parts in one of the cases to use the system until I got the "real" case done and started it up and the (A-64 3000) mobo temperature soared, it was like a cheap oven until I cut it up.
---I also saw that the only front intake was a small slot in the underside of the front plastic bezel, so I cut a couple strips out of the sides of the bezel as well. Looks lousy but doesn't give me overheating problems.

Mar. · Post by **Mar.** » Sun Jul 03, 2005 11:17 am

Lubb wrote: It harms nothing

Voids your warranty.

badbadtz560 · Post by **badbadtz560** » Sun Jul 03, 2005 1:09 pm

I'd think that a warranty on a case is somewhat useless and can be ignored... any warranty beyond gettin a beat up case on arrival that is

wwenze · Post by **wwenze** » Sun Jul 03, 2005 3:46 pm

I dunno about airflow, but at high wind speeds and pressures the grills can produce a lot of wind-cut noise.

Don't believe? Get a fan a put a grill on it.

~El~Jefe~ · Post by **~El~Jefe~** » Sun Jul 03, 2005 7:43 pm

I just am lazy to, but on an antec 37000 BQE case, eh, I duno, its kinda open. true, not better than fully open, I just think though that it cant do THAT much.

maybe i should test it. they made such an effort though in making it breathable, hate to bend up the case cutting or make it dangerous ya know?

but would it really be noticable a 7 volts on a pabst 120?

mathias · Post by **mathias** » Sun Jul 03, 2005 8:54 pm

I wouldn't do it with something as good as BQE/P180 thin honeycomb grills, mostly because I'd probably, instead of having a fan at the edge of my case, duct the CPU fan to the exhaust slot.

I have cut out the thick honeycomb grill on my 3700AMB, and now that I have such a duct, I wonder if the absence of the grill makes any difference.

Tephras · Post by **Tephras** » Mon Jul 04, 2005 8:25 am

I used to think that there was no need to remove the unrestrictive fan grills on my old Antec case until I read a post by MikeC in this thread where he wrote that even a wire grill has a surprisingly high impact on airflow.

MikeC wrote:Wire grills also have an effect: ~20%. This was checked with an anemometer on several different fans of 80, 92 and 120mm size, at full and lower speeds. The airflow reduction went as high as 24% but it was never below 19%.

At 12V, the reduction in airflow with most fans will be relatively harmless, though there is an increase in turbulence noise (audible to me). But at the low airflow rates SPCR members run fans, I think the airflow reduction is significant.

Shadowknight · Post by **Shadowknight** » Mon Jul 04, 2005 9:41 am

There can be circumstances where it IS beneficial to have a grill in place... such as keeping your kitty-kats from shoving their head in

flarkit · Post by **flarkit** » Tue Jul 05, 2005 12:54 am

Shadowknight wrote:There can be circumstances where it IS beneficial to have a grill in place... such as keeping your kitty-kats from shoving their head in

That's what cheap chromed wire grilles are for.

I'd say it varies from case to case (*cough*)... if the case has suitable grilles which have fairly large holes or the circular type that look almost like those wire grilles (the stamped one has a circular pattern in other words), then it might not be of much benefit.

On the other hand, those cheap square or small circular holes do add to the noise and restrict airflow. I was astounded by how much quieter my previous case was without the grilles. This immediately also implies that air is flowing through better.

Bluefront · Post by **Bluefront** » Tue Jul 05, 2005 4:08 am

IMHO....it is better to cut out the exhaust grill, than the similar intake grill. It has to do with back-pressure. An exhaust fan is much more affected by restrictions.

Test it yourself......put a foam filter in front of the intake of a fan and check the airflow.
Now put that same filter in front of the exhaust side of the same fan, and check the airflow. The difference is readily apparent.

But of course for max airflow, no restriction at all is the best. Who owns cats anyway?

scrandman · Post by **scrandman** » Tue Jul 05, 2005 9:59 am

Bearing in mind the grills on the SLK3000B are pretty open to begin with, it won't do that much for your temps cutting them out (perhaps 1C). If running at 12V, fan noise will be significantly reduced. If running at 5 or 7V, the difference will not really be noticeable.

nutball · Post by **nutball** » Tue Jul 05, 2005 11:33 am

Shadowknight wrote:There can be circumstances where it IS beneficial to have a grill in place... such as keeping your kitty-kats from shoving their head in

But this only happens once ... if you have sufficiently sharp fan blades

Shadowknight · Post by **Shadowknight** » Tue Jul 05, 2005 11:38 am

I've seen a picture on another forum where somebody modified his side panel to have 6? 120mm fans installed. The used aftermarket wire grills. His cat STILL managed to stick his whiskers into the blades on A REGULAR BASIS and kept accidentally trimming whis whiskers in half.

Mar. · Post by **Mar.** » Thu Jul 07, 2005 7:18 am

Bluefront wrote: It has to do with back-pressure.

Funny, say "backpressure" on a different forum, such as a car forum, and you'll start a flame war...

BrianE · Post by **BrianE** » Thu Jul 07, 2005 7:35 am

Mar. wrote:
Bluefront wrote: It has to do with back-pressure.
Funny, say "backpressure" on a different forum, such as a car forum, and you'll start a flame war...

[offtopic] Backpressure IS bad.... a lot of people don't understand that the trick (and hard part) is to reduce backpressure without killing exhaust gas velocity... not that the same principle is exactly applicable here. [/offtopic]

Mar. · Post by **Mar.** » Thu Jul 07, 2005 6:39 pm

BrianE wrote:[offtopic] Backpressure IS bad.... a lot of people don't understand that the trick (and hard part) is to reduce backpressure without killing exhaust gas velocity... not that the same principle is exactly applicable here. [/offtopic]

Yea, I know, but there are so many ricers out there that don't know that... And won't listen to reason.

Anyway, that's enough thread jacking for today.