How To: Properly Plan And Pick Parts For An Air-Cooled PC, Part 1

[jambu]

you don't need a ton of fan blowing air in all directions. make the hot air flow in one direction then you can get a more effecient cooling system and less noicy pc.

 

[intel4eva]

[citation][nom]amk-aka-phantom[/nom]They study this in 6th grade...[/citation]

They don't study heat pipes in 6th grade, you moron.

 

[AbheekG]

That's a wonderful article and a great effort! Thank You so much!

All this makes my Lexa S look real good! It came with 4 140mm fans and the way I setup the system seems to resemble the ideal config here!
My Phenom II X6 1090T never exceeds 45C, the HD5770 is always well within 60C and the HDD never crosses 35C. All that considering I live in Bombay, India and it's 38C here during Oct with over 80% humidity! Kind of proud I built it right, had really put in decent thought into it!

 

[ChromeTusk]

I wouldn't mind seeing compartmentalized / modular cases, but since they're not standard, few manufacturers will risk making parts for them. Unless you make non standard cases that still adhere to some ATX measurements and will fit ATX components without modifications. But does that lead to something like the Level X case that's prohibitively expensive?

I'm not sure how you can effectively separate the CPU and card airflow with a generic case. Suppose you have a partition wall between the two. It doesn't have to touch the board, but it does need to be relatively close to it for airflow separation. How can you assure it will fit the majority of motherboards without touching circuitry, VRMs, heatsinks and pipes, etc. It'd have to be some sort of custom work where the end-user has to cut away from the partition to fit their own board.

But ultimately, if you're separating the cards from the CPU, why would you want the fan on top of the card at that point? It would be right up against the partition, and that doesn't make sense to me. Unless you're proposing departure from the ATX motherboard, which would make this whole thing moot.

Agreed with more modular cases and as you said, any separation of air chambers over the MB is a custom job or a whole new standard. Even the Level X you mentioned only separates the MB/CPU/expansion cards from the other components. A partition within generic ATX cases would also only work effectively if both "chambers" had separate fans providing the airflow, another custom mod.

I want to see the 90 degree turned Silverstone cases in the next airflow review. I would be interested to see how they stack up.

I also have the RV03 and I hove how cool and quiet it keeps my system. The only two parts I hear are the optical drive and graphics card (blower style). Both AP181 fans are plugged into the the MB and regulated by the system/MB temp.

I have a Raven 3. It works wonderfully. Granted, I don't have a current rig to compare it to thermally or acoustically. But Tom's did a comparison review on it and five other cases a few months ago. You can check some specs on the Ravens there.

TechSpot also did a review of the RV03 - http://www.techspot.com/review/394-silverstone-rv03/

 

[ezareth]

Great Article!

I have an Antec 1200 case with a bottom mounted PSU that vents air from inside the case to the rear of the case. I also have a Gigabyte X58 mobo with the two X16 lanes sitting right next to each other.

Once I installed both cards the top card was running over 90C and the bottom card at 60C under load. I downloaded and installed MSI afterburner and created a different cooling profile which had the top card running at 73C and the bottom at 60C. The problem was the top fan was as loud as a hair dryer (70% speed) whenever I started playing a game.

To solve this I cut a half inch piece of semi-soft rubber from a old cleaning tool of mine and used it to gently "pry" the two cards apart a bit. This was well within the tolerance of normal "play" of the cards in the PCI slot but the difference was dramatic. The top card temperature dropped to 64C under max load and the fan now runs at a relatively quiet 50% instead of the noticeably louder 70% it was running at.

9C temperature drop even with the fan spinning at 20% less speed is quite a cooling improvement I'd say.

I have a side mounted fan on the way which should further drop the temps of my cards and I'll post the results here as well.

 

[avatar_raq]

Good info for beginners, useles for me. Lets hope part 2 has some advanced info.

 

[gio2vanni86]

I had a question if someone can answer it for me. I have the Antec 1200, i have my PSU facing upwards with the fan, seeing what you guys have stated the fan of the PSU should be pointed towards the bottom. But my question is shouldn't there be a certain amount of space between the fan and the floor so it can take in air or it doesn't matter?

 

[Onus]

A bottom-mounted PSU can only be mounted fan-down if there is a vent (preferably with a filter) directly under it. Otherwise, you have little choice but to mount it fan-up.
I have the Enermax Hoplite case shown in this article. I have no side fans installed in it, but did add a slow (typically runs around 640 RPM) top fan to it. My CPU (970BE@3.8GHz) has been idling around 29C lately. I haven't checked my GPU (560Ti) temps lately, but will remember to do so when I get back home this weekend.

 

[darknexus]

I run a setup with 3 intake fans in the front, 2 exhaust in the back, 1 exhaust in the top, and a bottom mounted back-exhausting PSU. I have a Noctua NH-D14 exhausting towards the back fans and a 12cm fan mounted mid-case pointing towards the back for extra flow. This sit so that it kinda blows across the top of my graphics card. My card is an Asus GTX 580, the one that takes up 3 PCI-E slots, so some air gets exhausted out the back but a lot gets dumped back into the case. To compensate for this, I have a side-mounted fan exhausting air, rather than pushing fresh air in. To me, this seems to work well, but seeing as all talk of side-mounted fans has them blowing air in, I am led to second-guess myself. I can feel nice, warm air coming from it so I know it's doing what I want it to do, but I thought I'd get some opinions on this.

TL😀R Is it necessarily bad to run a side mounted fan as exhaust rather than intake?

 

[theace26]

What better way to wrap up a scorching summer than with a last word on cooling? We explain the most important rules for creating ideal airflow, address the potential effectiveness of side fans, and discuss the finer points of graphics card cooling.

How To: Properly Plan And Pick Parts For An Air-Cooled PC, Part 1 : Read more

I noticed in the article that you had two side fans, blowing into the case as opposed to expelling air.

This question is posed to the community and possibly the author:

Setup:
is almost identical to the one on page "Airflow: Install Tower Coolers Right-Side-Up" fig. 1, however I have 6850's Cross Fired, with 2 expansion slot covers between them, with two side fans, 12cm & 14cm, expelling the hot air. With all cool air coming in through the front, entire front of case is mesh so air flow is good. The tower, Cooler Master CM 690 II Advance ATX Mid-Tower Case (RC-692-KKN2), is sitting in an enclosure, location of computer is basement, when i am using it the door to the enclosure is open.

So my question is:
Would it be better to have the 2 side fans blowing air into the case as opposed to the current setup? Is there enough cool air reaching the graphics cards?

 

[gio2vanni86]

[citation][nom]jtt283[/nom]A bottom-mounted PSU can only be mounted fan-down if there is a vent (preferably with a filter) directly under it. Otherwise, you have little choice but to mount it fan-up.I have the Enermax Hoplite case shown in this article. I have no side fans installed in it, but did add a slow (typically runs around 640 RPM) top fan to it. My CPU (970BE@3.8GHz) has been idling around 29C lately. I haven't checked my GPU (560Ti) temps lately, but will remember to do so when I get back home this weekend.[/citation] Ahh thanks for clarifying that. I almost felt as if i had to flip my PSU and call myself such a baddie for such a mistake. Though i've seen a few spacers in-between the bottom of the case and where the PSU sits. So i would need there to be a vent with a filter in order to do so if i wanted my PSU to be faced down. Wish antec would add that to there cases, would be very nice if they added it to there DF-85 or there Antec 1200 V3 particularly there DF-85 since I'm considering that for my next build. Thank again.

 

[andregoujon]

About the Corsair Graphite 600T, it doesn't have a lateral fan, it's not so perfect after all.

 

[AnUnusedUsername]

Anyone know what to reccomend when you have a bottom-mounted PSU case and the case has to sit on carpet? I realize I could go buy a plank of wood to sit my case on, but besides that I wonder if it's acceptable for the fan to still face down directly onto carpet, or if it would be better to take a hit on heat management and have it face up into the case.

 

[Onus]

I have my case on a plank. You could also mod some stubby legs for it, but be careful because the metal probably wouldn't take much lateral stress (e.g. if you bumped the case. One to two inch thick coasters under the "normal" legs might work too.

 

[Guest]

A google study of more than 100,000 disk drives in use in their systems found that drive failure rates were lowest when the drives operated between 35-45°C. Failure rates went up as temps became cooler or hotter than this.

Ref: http://static.googleusercontent.com/external_content/untrusted_dlcp/labs.google.com/en//papers/disk_failures.pdf

 

[Guest]

I have a question about top fan placement. If I'm using 2 top fans and aftermarket CPU cooler that blows air in the direction of rear exhaust fan, where should my top fans blow? I suppose the one closer to the rear should be exhaust, but what about the one closer to the front? If it's also exhaust, isn't it "stealing" air from CPU cooler? Would making it blow the air in help CPU cooling or disrupt the airflow in the case too much?

There would be also 1 front intake fan, 2 side intake fans and 1 optionally 1 bottom intake fan. It's Zalman Z9 Plus.

Halp!

 

[damric]

Good read. Let's see part 3 with various radiator configurations for water cooling or water cooling kits and how they affect system air flow.

 

[PIZZA Man]

Two quick noob questions. First, with the examples with side fans, are the side fans blowing in or out? Second, on the case temperature measurement graphs the coolest appears to be the "PSU Exhaust Air at 140 Watt Linpack" one. Which of the diagrams represents this configuration?

 

[RedJaron]

TL/DR Is it necessarily bad to run a side mounted fan as exhaust rather than intake?

And to everyone else asking about side fans:

There's no guaranteed best setup for side fans. It depends on the fan location and what components you have sitting "underneath" it ( usually your graphics card. ) If the side fan sits low on the case, it can generally be used as a cold air intake. If it sits high, you can usually use it for CPU exhaust. If it's in the middle, check your GPU cooler. If your GPU has the "leaf-blower" type fan, where most of the exhaust is vented out the back of the case, you can use the side fan to feed cool air directly to the leaf blower. If your GPU cooler vents half or more of its air back into your case ( as most aftermarket or specialized cooling mods do ) you can use the side fans to vent the hot GPU air out of the case. Note that in this setup you should make sure that you have an intake fan that reliable delivers cool air toward the video card.

As for the question regarding the top fan stealing air from the CPU cooler, again that depends on how everything else is working. If your CPU cooler points up to the top of your case, or "downward" into the motherboard, then by all means use the top fan to exhaust the hot CPU air. If you've got a CPU cooler pointing to the back of the case, you should use the rear fan to exhaust the hot CPU air. If the top fan sits farther back, on the "hot" side of the CPU, then it should help exhaust the hot air. If it's set to intake at that point, you may blow some of the hot air back down into the system. Conversely, if the top fan sits at the "cold" side of the CPU, it should feed the CPU cooler more cold air from outside the case.

And as a final note, remember different fans move different volumes of air, so don't feel like everything needs to be on high blast all the time. If you're worried about "disrupting airflow" with over powerful fans, turn down the speed. Many motherboards have BIOS settings to change up fan voltage to control speed ( and noise. )

 

[sephirotic]

I hope part 2 comment about VORTEX and Difference in intake/outtake flow and pressure. While is different to predict how vortex would affect the efficiency how air flows from through the whole case what i tried to do on balancing my Thermaltake element T airflow is installing high performance back and top exausters and mantaining moderate intake side and front 120fans. A fan controller was also importante even tough cable routing and adapters where a hassle. (Ideally a case that has it's own fan controll and connectos would be the ideal).

My current system has the following fans:

Intake:

Front:
120mm : 70cfm
140mm : 70cfm

Side:
200mm : 110 cfm

Total Intake: 250cfm

Outtake:

Back: 99cfm
Top: 80cfm
GPU: 60cfm (estimated, i couldnt find official data about the 6870 standard cooler outtake)
Total outtake: 240cfm

(extra: CPU: 89cfm, tends to help outtake, but in a very low efficient way, since it diverts airs trom the top exaust and throws in front of the 99cfm back exaust fan, thus it barelly increases the outtake flow. Happilly tough it does not degrades it as i my tests revealed)


As you can see, airflow for intake and outake is almost identical with should provide the most optimized pressure inside the Case. Unpredicted Vortex may interfere in how efficiently air escapes through outtake fans but i made an extensive testing with my fan controller increassing and decreasing all different combinations of all my 5 fan speeds possible and in the temperature drops were all proportional with the speed of the fans: With all the fans at maximun, temperature drops were also at maximun. I don´t have the data here now, but if i recall correctly, without touching the cpu's motherboard default PWM preset, with all the case fans at maximun temperatures were actually 5~6 degrees celsius lower than at lowest speed.

So it was a good investment in fans that i made for my cheappo TT case.

If anyone interest, send me a pm and i may post some pictures.
(Please Excuse my english mistakes.)

 

[sephirotic]

Another relevant comentary: I have a 200mm side fan in my optimized Therlmalte element T. All the 5 fans in it are controlled by a front bay controller. The Side fan is 110cfm and is actually the one witch more decreases the whole system temperature after the 99cfm back outtake fan when in maximun speed.

Frontal Intake fans has the lesser influence followed by the top 180mm 80cfm fan.

 

[youssef 2010]

This article is extremely useful for everybody. Thank you, toms

 

[yasir siddiqui]

That is great and effective guideline.

 

[Guest]

I recently faced a overheating problem with my computer shutting down on playing heavy 3D gmes. My computer technician dusted my graphics card now all is well. He suggested me to buy a cabinet with side cooler preferably with 12" side fan. This article came at the right time for me. Thanks.

 

[tomhuang03]

This article enlightened me a great deal.