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

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.

At least in Europe, the summer wasn't really all that warm. But for a PC owner or do-it-yourself builder, the issues of waste heat, cooling, and ambient temperature are always worth thinking about. That's why we're going to start at the very beginning in this, our introduction to cooling. Every year we have new readers, and every year we see some of the same questions posed in our forums. The very last thing we want is for an expensive project to fail as a result of a mistake made in the most basic tenets of keeping hardware running at acceptable temperatures. 

Because the topic is extensive, and because we want to offer a comprehensive tutorial, we'll present the whole story in two parts (the second of which will appear next week).

So, first we'll talk about the best sort of chassis, including the mounting location of the power supply. Then, we'll take a look at the potential drawbacks of other solutions. Optimized airflow is the most important consideration in an air-cooled system, so we plan to go into a lot of detail on that. Then, we'll take a look at classic case fans, and show why even a beginner doesn't need to be afraid of applying thermal paste. If you also bear in mind the importance of having space between your multi-GPU configuration and understand why the often-maligned side-panel fan can be useful, your PC will be better-equipped to survive next summer's heat.

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  • aje21
    Quote:
    low-profile Radeon HD 6850

    Interested to see a bit more about this...
  • 13thmonkey
    Really interesting article. I think you are overplaying the convection angle, at the temps you are talking about there is not much convection, and any fan will overpower it with ease. My biggest concern about this is the power supply page, the middle version is preferable to the first version if there is no dust filter, and i would say is not a bad configuration. Perhaps not optimal, but not bad/wrong. All of the other 'wrongs' make sense.
  • Gothams Finest
    Very interesting article.
  • Lizard_of_Bodom
    Nice article, thanks for that. I had spent some time myself to experiment with cooling on my CM-690 II

    + 6 fans. Having front, rear and top blower already on in standard way, I had added 2x14cm coolers on

    side of the case. After some tests, it came up, that temperatures of CPU and GPU are actually lower

    when fans are SUCKING the air out rather than blowin inside the case. Difference was about 4 or 5 deg.

    It has probably lot to do with the fact , that my GPU has 2 axial fans rather than outside-blower

    configuration, however it shows it is worth sometimes to experiment with the flow and it may show

    unexpected results.
    Also I noticed (case have space for 2 top fans) that having 1 top fan blowing OUT the air, the other

    fan-bay just beside it creates suction and directs the air INSIDE the case, so my next idea is to put

    another fan blowing air INSIDE, creating some sort of U-shaped airflow from top trought side-mounted

    cooler and back to top again. I guess its worth trying...
  • Gothams Finest
    Anonymous said:
    Nice article, thanks for that. I had spent some time myself to experiment with cooling on my CM-690 II

    + 6 fans. Having front, rear and top blower already on in standard way, I had added 2x14cm coolers on

    side of the case. After some tests, it came up, that temperatures of CPU and GPU are actually lower

    when fans are SUCKING the air out rather than blowin inside the case. Difference was about 4 or 5 deg.

    It has probably lot to do with the fact , that my GPU has 2 axial fans rather than outside-blower

    configuration, however it shows it is worth sometimes to experiment with the flow and it may show

    unexpected results.
    Also I noticed (case have space for 2 top fans) that having 1 top fan blowing OUT the air, the other

    fan-bay just beside it creates suction and directs the air INSIDE the case, so my next idea is to put

    another fan blowing air INSIDE, creating some sort of U-shaped airflow from top trought side-mounted

    cooler and back to top again. I guess its worth trying...



    You should also try adding two 120mm fans on the bottom.
  • Lizard_of_Bodom
    Anonymous said:
    You should also try adding two 120mm fans on the bottom.


    I was planning to, also - just to check how the airflow gonna work, althought I dont expect too much. I wonder if it not disrupt the natural flow or maybe improves it?...
  • 13thmonkey
    if you want to know what happens when countering convection, turn the case updside down (reseat the cpu cooler so the heat pipes work, i'd suggest 1C difference (gut feel).