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sleepy_yellow

suggestions about air flow...please

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hey all,

 

i have a Lian li PC-71 that i've been having for about 2 years now, and i'm not too happy how the air flow is going now because its pretty packed i must say. i mean i have 4 hard drives in side that are running pretty warm when the window is not open.

window open = 36c idle HDD | CPU 34c idle | GPU 50c idle | PWMIC 38c idle | chipset 40c idle

window closed = 44 idle HDD | CPU 39c idle | GPU 55c idle | PWMIC 45c idle | chipset 45c idle

 

i know its not that bad but i'm obsessive with temps just in case haha because under load it really gets hot in there i mean even tho this case is aluminum you can feel it heating up so that just worries me.

 

its funny how much difference the window open can do. anyway i was thinking of upgrading fans from the stock ones that came with the case, what i had in mind or i thougth of drilling a hole to fit a 120mm in the front but i dont want to wreck this nice case even tho it wont be visible, but still i really like this case.

this is what i thought i should do:

caseairflowplanen7.gif

 

 

pic of the case, its an older pictures and doesnt look liek that anymore, but still same stuff inside except for that one fan that is blowing on the PWMIC cuz i noticed it doesnt really make a big difference lol

img0854oo5.jpg

 

thanks for your opinions

 

-s

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heat rises, so fan blowing up would like 2 deg's i suppose

 

what u need is more air in, u can try fitting a 92mm or 120mm in the front, and turning it up a bit, so more colder air gets in, that will make the most difference

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oh ya heat rises haha, thanks

ya well i was trying to avoid cutting the front. i just thought i'd put fans that have a better CFM in front and on the side where the gpu is a fan that blows out too to keep the gpu cooler because the gpu is my biggest concern.

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If you can match the CFM going in to the CFM coming out you should get good airflow. The fact that your temps go up when the side in on means there is bad airflow. The others are right, always make your top fan as an exhaust. The heat being dispelled out the back by the PSU and rear fans can be dragged over the top of the case and blown back in if you have it as an intake.

 

You could also put a fan hole in the removable case side, that would be opposite the chipset and add a funnel to direct the airflow right to the heatsink and get rid of the loose 80mm fan you have. I suppose you could do that for your memory too.

 

I would also remove the fan grills from the inside back fans and the CPU fan too, will give you more airflow and less noise.

 

Dont get me wrong it looks pretty cool as is and I dont want to sound to critical, but you have to get the most from a nice case like that dude

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the intake... its bad... lol

 

first, like everybody said, keep the blowhole blowing up..not down...

 

second, ur only intake had to go through some warm harddrives... move the harddrives somewhere else n ull notice the temp will drop significantly. and its a 80mm to boot lol!

 

or if u feel like playing around with cut metal, go for a dremel and cut another fan hole on top of the 80 in the front... and/or get a bigger hole than 80...

 

ur intake is the cause there.....

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I've heard it both ways that heat rises, but also that it doesn't rise enough to make more of a difference than other factors. In some situations, it may be better to have the top fan blowing inward. The extra airflow may have more of an effect than the rising heat would.

 

It's kind of like how the Coriolis effect makes toilets flush in the opposite direction in the southern hemisphere. This is a myth as there are a multitude of other factors which all exhibit more force upon the direction of the water than the Coriolis effect, which exerts a pretty small force in comparison. And unless your case is six feet tall, I don't see the rising heat theory making that much of an effect in the scheme of things either. By the looks of your design I could see it going either way, especially since your design needs air intake so badly.

 

My best advice is to test it both ways and see how it goes. However my very best advice, as long as you're modding your case, is to get yourself a side panel intake fan, unless you've got one already. That plus your blowhole fan will make a big difference.

 

And yes, get rid of those grilles on the inside of the 80mm fans. There's really no reason to have grilles on the inside of a case, and those grilles look like stamped steel, which can cover up to 3/4 of the entire aperture. If your case has grilles cut into them, cut them out with a Dremel or a pair of cutters and replace with a wire grille. Anywhere you see stamped steel grilles, get rid of them. Just replacing and removing those grilles will help airflow considerably. The CPU fan has a wire grille so it's probably not impeding airflow too considerably.

 

Basically, you want grilles in two places: wherever a fan could be touched from outside the case, and wherever a stray wire might possibly hit (mostly the CPU fan), and in the latter case it is better to redirect your wires.

 

So in short:

 

* Test top blowhole fan in either direction

* Get a side fan

* Remove or replace all stamped steel grilles

 

Hope this helps.

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I'd think that if you're already considering cutting a hole in the top for a blow hole, you should re-think your aversion to enlarging the front hole for a 120.

 

Especially if it can be done without it being visible outside of the case.

 

Your options for high cfm intake fan are a lot better in the 120 class than they'll ever be for an 80.

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i guess you guys are right since i'm using the dremler in the first place why not just use it for the front. the front just looks really thick and that means imma have to get a pretty strong disk for that and sincei never really cute a whole with a dremler eventho i own one i hope it will turn out ok.

because for the top and the side i just thought i'd drill a bunch of little holes like it looks on the front. and touch it up with some black paint.

we'll see i'll start this saturday. now i'm gonna go look for osme 120mm fans

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Why not use some cardboard or something to split the CPU from the GPU. I.e. create two mini windtunnels in your case. Also helps if you can have a suck-blow on each one.

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A better alternative would be to use the Dremel Circle Cutter Attachment.

 

 

This may appear to be a little off topic but in comment to the previous post quoted above:

 

This attachment may be good for cutting holes in soft materials such as wood, plastics, fibreglass, etc. but I would not even think about using it to cut holes in sheet steel or aluminium in this case (no pun intended! :) )

 

The clamping arrangement is insufficient and the cutting tool/bit would "grab" as it cuts and for those of you who have experienced drilling thin sheet steel or any other metal you will know only too well that this is quite dangerous.

 

Good luck with the air circulation problem. Regarding the 120mm diameter blowhole at the top of the case I have done exactly the same mod a number of times and have the fan exhausting air out the top of the case. Not only does it expel hot air it helps to create good air-flow beginning with the front intake fan(s). I would also remove any fancy designed fan grilles and replace them with the standard wire grille. On the outside of the case too, as this obstructs airflow.

 

If noise is not a consideration then why not use fans with a higher CFM rating? Guaranteed to get results.

 

That's a nice case, the early model Lian-Li PC 7X Full Tower Server case?....? I believe they have brought out a newer version that utilises 120mm intake and exhaust fans. It's this newer model that I will be using in my NF4 W-C rig.

 

Regards,

 

Peter :)

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