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Guide to Air Cooling v0.1 (inside - maybe no 56k)

33443 Views 28 Replies 13 Participants Last post by  linh1987
First first: Looking for feedback on this writeup
.. Constructive please. "You suck" while often applicable, will not help in this endeavor.

First: I don't work for NASA or a company that specialized in airflow. I have, however, actually done "smoke" tests on airflow using plexiglass panels to watch airflow, have used special plexiglass covers with holes that I can intert small "gauges" in (by gauges, I mean a piece of wood with lightweight string (smaller than human hair) attached) to see where I am having issues. If I feel like calling something "baffling" - that is what it is. There is probably a more applicable scientific name, but I don't care


So read at your own risk, your results may vary, void where prohibited, some assembly required, edited for telivision, colors in time, may fade....

The key concepts:
- HEAT
- Air flow removes heat from sources
- Radiant heat sources will heat air from distance
- FLOW
- Adding 52,000 CFM of fan power may make things worse - where is that air going and how is it behaving? (See circular arrows in diagrams below.. )
- To predict flow, there needs to be equality (intake vs. exhaust) - can be forced (fan) or space (holes, gaps, whatever..)
- Cables, the height of cards, etc can greatly impact flow.
- BALLANCE/RESISTANCE:
- Keeping ballance between intake and exhaust - else, air goes where finds least resistance - do you know where that is?
- CONTROL
- Just having lots of fans running full speed ahead is not always the best thing.. Nor can thermal sensor units always be the answer. One hot component can be impacted by more than one fan - and having all fans spin up if one is running hot may not help it.. Know your fans, their RPMs, their CFM and their position... (I like Vantec manual 3.5" fan controllers personally.. I can dial it around and get used to it without having to read some POS display)
There is so much that can impact this. Hell, just moving from some POS Creative 24bit card to an Audigy 4 changed my case cooling dynamics in more ways than I care mention. Do you have to be as anal as me about it? Probably not, but it is indeed an interesting adventure getting good cooling...

GUIDE TO DIAGRAMS:
- Arrows are samples of air flow.. Dark blue = cold, light blue = less cold, light red = warm, red = hot...

OK, lets get started.. Consider the following case layout:



A fairly standard case. The main challanges here are lack of air in dead spot below bottom PCI, GPU pushing hot air back into the case and little HD cooling. Since the fan s blowing striaght into a wall (PCI cards, back of case) a natural baffle tends to develop that pushes air around it.

What if we add a different GPU cooler (perhaps an NV 5 or similar exhaust style setup that takes up a slot and exhausts GPU air out):



We are now increasing draw towards back of case and removing the exhaust of the GPU back into the case. Cooler air will be moving into rest of case. Might get some extra help cooling other PCI (but my thermal probes were a little inconclusive on this...) Either way, your CPU now has some slightly cooler air heading its way and your GPU is much happier.

What is we add even more? (Nothing like drilling the top of your case!!!!)



Hrm, just noticed I forgot the PSU in the drawings.. anyhoo.. By adding more exhaust, we have to hope that our intake fan is big or can outpace the exhaust fans - else lord knows where it will draw air from. But with extra pull from top of case (where heat tends to collect) we will be helping the PSU, CD/DVD, RAM and anything else in central MB proximity. Combined with the GPU cooler, about the only thing we have not resolved is the HD.
Drop a fan cooler on the front of it (or even just drill holes in the 2.5" bezel in front of it to allow more draw from it...) You are set


Which reminds me of a story involving a friends dual Opteron system, an Antec 4u server case and a sawzall... but that is for another day...

Now how about your standard mid-font intake system... (I hate these...)



Put the HD in the 3.5 with the floppy or not.. doesn't matter, it is still screwed. The GPU and PCI slots are in rough shape also.

How about we add a small HD cooler (some 40mm fans..):



Now we have some serious HD cooling - and are probably helping the GPU as well. Throw in some GPU 3rd party cooling:



There we go, things are happy


THE LONG AND SHORT:
Think about your case. The height of PCI cards. The other "solid metal" in the case (for example, I have drilled more holes in Lian Li case parts than I care mention - like the 3.5" front tray on PC6x cases I drill a boatload of big holes in to increase upwards airflow - there is no reason for solid metal there - help HD, RAM cooling...).. Wires, holes.. Hell, the best cooling I got out of an old Antec case was yanking out a slot cover just below the GPU - it dropped my temp 10 degrees - no fan or $$ required!

Having an exuast side port just above the CPU changes case dynamics a LOT.

PARTS I USE:
There are of course different applications.. But there are a few thigns that every computer I build has (OK, showing most recent parts available, but my older systems have equiv, even if older, uglier and.. whatever):
Vantec 3.5" Fan Controller
(I have one system with two of these to handle the fans - to make sure I can dial flow *exactly*)

Case fans are a bit of a mix.. I have sometimes gone with volume (when needed) over quiet/volume ratio..
For "crank it up and blow the door off" volume (WHEN NEEDED!!!! AND AS WORKS WITH FLOW!!!).. Different sizes, etc...
For general case applications, even though I never use the fiter or cover, I use THESE (again, difference sizes, etc...)
Both tend to be quiet enough when quiet is needed - and blow the doors off everything when required.
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Discussion Starter · #3 ·
Air cooling could probably take up its own site...

Top rear exhaust fan, front bottom intake fan, HDs in front of intake fan, ..

Top rear exhaust fan, front bottom intake fan, HDs behind intake fans...

et al.

What is best way to properly describe this to someone staring at their case and having no idea how to proceed?

I. Have. No. Idea.

This is atttempt one


Maybe create index at top based on case type/fan location (or possible location - and how to find out if you have possible location...) ?????

Edit: What is rep+?
 

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Quote:
Edit: What is rep+?
It's a way people using this forum acknowledge the fact that you have done a good job / given good advice on a certain thread.

Just one question... What do you exactly mean by "air goes where it finds the least resistance" when you say: "Keeping balance between intake and exhaust - else, air goes where finds least resistance - do you know where that is?"
 

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Discussion Starter · #5 ·
Consider water...

Your case is in water. You have 3 intake fans, no exhaust.

You are pulling all kinds of water into the case - but where is it going? Air principles are the same - although the space/friction requirements are lower.

You have 3 intake fans and have a 5.25" bezel missing from the front of the case and thus the 5.25" hole is where 80% exhausts?

(Of course there are all kinds of cracks, etc that air can excape.. but when you create a pressude differential, air will mostly head out the easiest path - the biggest hole/path.

A few slot plates missing in your PCI area.. that is where air is getting out most easily? Or pulling air in (stock GPU coolers if airflow does not overcome it...)

You have two fans pushing in at 40 cfm and one exhaust at 40 cfm. A few things happen - a) your intake fans will lose power trying to create basically a pressurized case and/or b) the air goes somewhere else...

The "somewhere else" is a wildcard in case cooling. I have known people to use caulking on cracks in cases to create total known air flow (I think I need better friends...)..

"It's a way people using this forum acknowledge the fact that you have done a good job / given good advice on a certain thread."

Ahh.. I have been wondering what that was.
Can you slam someone too? (I tried looking around for that option.. like.. "this post sucks.."
 

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Yesterday I instaled 4 case fans. One at the front bottom(intake fan) at 12V, one the rear top(exhaust fan) at 12V and two at the top(exhaust fans) at 5V. Now my PC is at a good temeperature and its very quiet. Today Im planing to make some holes at the front to instal the small ex vga fan(intake) betwen CD and DVD drive(at the front top if the case), hope it will work fine to.
 

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Quote:

Originally Posted by satansmurf

Ahh.. I have been wondering what that was.
Can you slam someone too? (I tried looking around for that option.. like.. "this post sucks.."
That option was removed along time ago due to severe abuse, Instead of negative repping, You can just report a post.

Brings it to the Section Director's attention.
 

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Discussion Starter · #8 ·
Not sure of your placement, but adding cooling near the top front may just feed your top exhaust...

You placing it how far down and how much push?

You could end up basically intering air in the top front.. and exhausting it in the top middle... Not sure how well that will help. Your 5.25" things having issues?

(Volts, while interesting, don't belay the impact of a fan.. How much force/cfm does...)

Edit:
Ah, on rep, I guess that makes sense
 

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Discussion Starter · #10 ·
I want to be careful about what I said...

If you are having heat issues in the top front of your case.. adding some flow may help. Hell, removing a bezel may help

But fixing true problem areas may help more.

Just want ya to think first


What is your GPU cooling situation? Flow?
RAM? Much flow over it?

Not sure on your MB + Case + Fan getup.. The thing is to just step back.. Hell, make a little drawing on paper - and look at intake areas, exhausts and blowers (things that just move air around inside the case like stock GPU coolers...)
 

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GPU cooling situation is very good, when not clocked its on 30C and clocked after 3h of playing its on 41C. I got VF700-AlCu LED on it and one small case fan over it to take the hot air faster to the exhaust case fan.
I didnt do anything with my RAM, they work fine and dont seen to heat.
 

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Discussion Starter · #12 ·
Then adding more front cooling may be overkill


You have a bad temp somewhere?

(Cooling for the sake of cooling means.. well.. money you could have spent on the next video card...)
 

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Well I dont have any problem with temperature, I just have one unused fan and a lot of free time now
. Thank god I have enuff money to buy a new 3d card right now but I dont need it, the old one is fine. Just dont like to throw things away.
 

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My case is a Thermaltake SViking. It has a clear side door that opens up. Should I keep this open to let me computer cool a lot more? I figured that would be bad 'cause dust can collect. Should I just keep a can of compressed air handy so I can blow dust out whenever it gets a bit built up?
 

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Quote:

Originally Posted by Patrice Mersault
My case is a Thermaltake SViking. It has a clear side door that opens up. Should I keep this open to let me computer cool a lot more? I figured that would be bad 'cause dust can collect. Should I just keep a can of compressed air handy so I can blow dust out whenever it gets a bit built up?
It's preferable to keep your side panel closed.
I have the same case and I can tell you those dual 120mm fans do a great job at creating good airflow inside the case.
If you open your side panel not only will you let more dust in but you will also short circuit your airflow since your rear fan will draw air from its immediate vicinity instead of drawing if from the front and forcing it to pass over your cpu heatsink.

If you decide to use compressed air just make sure you spray in small bursts (3 seconds or so).
Do not keep your finger pressed on it for like 10 seconds because the air it will spray will most likely become humid.
 

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looks like a great guide! but hows this for air cooling!!!!!!lol just temp
LL
 

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Quote:

Originally Posted by z_one
It's preferable to keep your side panel closed.
I have the same case and I can tell you those dual 120mm fans do a great job at creating good airflow inside the case.
If you open your side panel not only will you let more dust in but you will also short circuit your airflow since your rear fan will draw air from its immediate vicinity instead of drawing if from the front and forcing it to pass over your cpu heatsink.

If you decide to use compressed air just make sure you spray in small bursts (3 seconds or so).
Do not keep your finger pressed on it for like 10 seconds because the air it will spray will most likely become humid.
Good information, thank you.
 

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Discussion Starter · #20 ·
Yes

Edit:
And doing so can take some work.

For example, I had to snip some plastic off the top of the voltage heatsink pegs on my MSI 6800GT in order to fit an NS5 on it.
No big deal, you just can't be shy
 
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