# Removing Grill from Exhaust Fan



## SIMP

All,
How much difference will it make to cut out the perforated grill at the back exhaust fan?  Seems to me that that grill limits the amount of air that fan can pull out of the case?  I own a Centurion 534 as shown below.


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## Mankz_91

I did it to my case, and I used tin snips.

I say more air is coming through, and its slightly quieter, but that is based on the un-scientific ear test.


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## Cleric7x9

i can assure you that it is not the grill that limits airflow, there is no way a case fan is pushing things to the max. all you are going to do is get your fingers caught in the fan. i really dont think it would help you


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## fortyways

Cleric7x9 said:


> i can assure you that it is not the grill that limits airflow, there is no way a case fan is pushing things to the max. all you are going to do is get your fingers caught in the fan. i really dont think it would help you



Wrong.

Removing stock fan grills is always a good idea.


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## OvenMaster

*taking notes here* I was asking myself this very question this morning, as to whether or not it's a good idea.


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## diduknowthat

Removing the grill makes a pretty noticeable difference in air flow, and a slight difference in sound levels. I would recommend putting on a fan grill afterwards though, so you don't get your hand caught up in it.


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## fortyways

OP's picture actually looks pretty open. It looks sort of like the honey comb design on Antec cases.

On my CoolerMaster case, it had tiny little holes. It was more closed than open.


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## vonfeldt7

I doubt it limits too much airflow...however I may be wrong.

The only thing I've ever seen that needs to be removed/cut to get better airflow is the plastic on top of the TT Armor Case. It has extremely small holes, and almost no air gets out. Bad Design.


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## jgotfire

2 1/4” works good on the 80 mm and the 92 mm.  I would not use these sizes of bits where they will show but on the back and under the front cover it works good.  Yes a cheap wire fan guard is a must.

IMO it will cut the fan noise by 1/3 or more and you can feel the difference in air flow.  2 1/4" is 83 MM if I’m thinking right.


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## Kornowski

I was thinking this myself actually...






Would it be worth doing it to the Antec 900, and what tools can you use?


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## Timo

Some of these might do it.

And I am sure that if your case-fan is blowing for instance at 1000 RPM, it's going to get more CFM through the back opening when there is nothing behind it keeping the air from going outside. So saying it won't help is quite untrue if you ask me.

I most likely will take out a big part of it myself soon (with my soon to be Antec 300) seeing the fans I am getting for it throw out 110 CFM... I'd like all of those CFM's to get out. But not all of it seeing I have a lot of wires running on the behind.


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## diduknowthat

Kornowski said:


> I was thinking this myself actually...
> 
> Would it be worth doing it to the Antec 900, and what tools can you use?



I don't think it's really worth doing on honey-bomb exhaust designs, as they are very efficient. However it is definitely worth to do it on the cheap punch out ones.


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## Timo

And what would be the significant difference between a honeycomb and a punched out one? A wide open one always works better.


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## diduknowthat

Timo said:


> And what would be the significant difference between a honeycomb and a punched out one? A wide open one always works better.



Cause it's kinda dumb to leave the fan completely open in the back, and a standard chrome fan grill is about the same as honey bombed ones.


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## OvenMaster

diduknowthat said:


> I don't think it's really worth doing on honey-bomb exhaust designs, as they are very efficient. However it is definitely worth to do it on the cheap punch out ones.



You mean like the one I have?


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## Kornowski

Yeah, I think it'd be worth doing it on yours, Tom? It is, Tom, Right?


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## diduknowthat

OvenMaster said:


> You mean like the one I have?



Yup, those kinds.


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## Timo

Available everywhere, put it on there. These will most likely let the most air through it, and if you're still not happy with that you can vut out as  much as you want.

@diduknowthat; the question was "How much difference will it make to cut out the perforated grill at the back exhaust fan?" And I said, it would make a pretty nice difference. Ofcourse the wires are now able to get caught etc. but I can imagine anyone knows that there is a risk to having no protection from a fan is hazardous.


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## SIMP

Update: I have removed the back grill guard with some wire snips I had and they worked great.  I can actually tell a difference in the airflow.  

I also ordered a side panel for my case with a view window and installed some cathodes inside my case.  The new panel does not have any side intake fans like the factory panel did, so I installed a 120mm fan in the front of the case for intake purposes.  My CPU temp went from 21 C at idle with the old panel to 27 C at idle with the new panel that has no side intake fans.  

This weekend I plan on cutting a hole and mounting a 120mm fan on the side of the new panel.  I hope this helps bring my temps back down to 21 C.

How bad does 27 C at idle sound with a room temp of about 75 F?  I am running an Intel E2160 at 2.4 Ghz.  Thanks.


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## Calibretto

SIMP said:


> How bad does 27 C at idle sound with a room temp of about 75 F?



I don't think temperatures make noise  The fans do though!


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## jimkonow

Calibretto said:


> I don't think temperatures make noise  The fans do though!



*facepalm*

those temps seem to be pretty good for a 75f room


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## Timo

Well... 21C with a room temp of 75F is impossible seeing 75F is 24C exept if you use some of the special cooling stuff (-273 liquids  ^^). So I am guessing those temperatures are incorrect...


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## Trizoy

Calibretto said:


> I don't think temperatures make noise  The fans do though!



You're right temperature doesn't make noise.. The most noise in the fan system is coming from tumbling air. When it is forced out those grills you are talking about the air doesn't have a smooth flow. If the grill were removed it would be a lot quieter, and you would only hear the fans.


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## TFT

If you do the maths , as an example. A 120mm fan can move 170CF of air in one minute and the punched holes won't allow that amount of airflow through so a wire guard or none at all would make the cooling more efficient and quieter.


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## Timo

Wow... Can you tell me which 120mm fan blows 170CF/M I have yet you find one?

(or are your minutes perhaps longer then mine?)


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## TFT

Timo said:


> Wow... Can you tell me which 120mm fan blows 170CF/M I have yet you find one?
> 
> (or are your minutes perhaps longer then mine?)



 My typo, should have read 70


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## SIMP

Timo said:


> Well... 21C with a room temp of 75F is impossible seeing 75F is 24C exept if you use some of the special cooling stuff (-273 liquids  ^^). So I am guessing those temperatures are incorrect...



Well, I was guessing at the temp in the exact room my PC is located.  I was using Core Temp to measure the CPU temp which I believe is fairly accurate.  Who knows!


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## Timo

Well, even if you would have a room temp of 15C (which is cold enough to make you pull on a second sweater inside the house) you won't have your Overclocked CPU run at 21C on normal Air cooling. I bet you that it won't even do 21C when you underclock it with a room temp of 21C xD


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## SIMP

So, is 27 C a decent temp then?


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## Timo

I wouldn't buy that Temp-reading program you are using... It's damn sure that's a faulty temperature. How you you expect to get a 27C when your room is 24C. It's impossible with any heatsink that is out there... Heatpipes can't do such low Delta-temperature between room and CPU temps seeing then they would work because if the room temp makes the heatpipe work you won't have any use of them.


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## Okedokey

Cleric7x9 said:


> i can assure you that it is not the grill that limits airflow, there is no way a case fan is pushing things to the max. all you are going to do is get your fingers caught in the fan. i really dont think it would help you



agreed


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## Timo

By that definition a car does not get limited by air resistance (and other resistance but air being the biggest). If you are blowing at a candle and I decide to put a piece of paper with somewhat of a mesh layout (with openings) between your mouth and the candle I reckon you'd have to blow harder then normal to get the candle to die out within the same time as normal.


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## Okedokey

I am not saying it will do nothing, rather the effort does not justify the improvement.


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## myPCrocks

The little bit of airflow you will gain is not worth it.

If you need to mod it to gain that small amount of cooling difference you have bigge rproblems than that.


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## diduknowthat

Timo said:


> Wow... Can you tell me which 120mm fan blows 170CF/M I have yet you find one?
> 
> (or are your minutes perhaps longer then mine?)



http://www.sidewindercomputers.com/delffb1212eh.html



bigfellla said:


> I am not saying it will do nothing, rather the effort does not justify the improvement.



The air flow increase is noticeable, but not drastic. However, due to less turbulence, the fan is much quieter with a chrome grill. Plus, its likes a 15 min job, especially if you don't get nitty-gritty.


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