Case Fan Direction?

Discussion in 'Computers' started by Mark Shannon, Oct 19, 2003.

  1. Mark Shannon

    Mark Shannon Screenwriter

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    I had my computer custom made, but I guess when we included all the specs we wanted, we forgot to include a case fan. Alas, I finally got around to getting one, but I have a question... What way is the fan supposed to blow? Inwards or outwards?

    Right now, I have it blowing outwards, and as it is, the power cable cannot connect to the motherboard (it's not long enough to reach the connection), so it cannot be controlled by the motherboard. It's connected directly to the power supply, so it's always running (which doesn't bother me, as it's extremely quiet).

    If I did turn the fan around to blow inwards, it would be able to connect to the motherboard.

    So my question is, which way is it supposed to face?
     
  2. Chas_T

    Chas_T Supporting Actor

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    Mark,

    The object is to remove the heat from the box and create air circulation over the components, pulling cooler air in from the outside.

    Therefore, if the fan is on exhaust, versus intake, it would be pulling cooler air in from the outside via the vents in the case, circulating the flow over the components, cooling them down and removing the heat generated in the process.

    That has always been my approach and mindset. Someone else may see it different.

    http://www.endpcnoise.com/cgi-bin/e/...ercooling.html

    Charles
     
  3. John_Berger

    John_Berger Cinematographer

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    It doesn't matter which direction. Cool air will enter the case regardless. If you have two areas for case vents (such as one in the front and another in the back), you should have the one in the front take are in with a filter in place to keep dust bunnies from forming in your system. The other fan in the back should be set to exhaust. That way the front fan forces cool, filtered air in, and the back fan takes any hot air out. Any differences in pressure will be managed by allowing air through the case vents.
     
  4. Hanson

    Hanson Producer

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    Blowing out made a huge difference for me. It was the difference between stable and crashing. If you blow in, you will swirl around hot air with the cool without an active venting system. Blowing out ensures that hot air is actively streaming out of the box.
     
  5. Glenn Overholt

    Glenn Overholt Producer

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    The basic rule is that hot air rises up. PC's are made with the fans in front sucking cool air in. They are often near hard drives and help to cool them.

    The fans in the back suck out the hot air. Namely the CPU, but today's cases aren't really designed efficently.

    The top of your case should have exhaust fans for blowing the hot air out too, and most don't. Just don't butt up the front of your case against something, as this way no cool air will get sucked in.

    Glenn
     
  6. AllanN

    AllanN Supporting Actor

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    I agree with one fan out closer to the top and one fan in. Also its a good idea to have the airflow going over the processor where the majority of the heat is generated. This will help remove the hot air generated by the processor. If your into case moding and serious airflow a top or side fan can be installed as well.
     
  7. Tekara

    Tekara Supporting Actor

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    well, when in doubt buy some inscense and put some seran wrap over the side and smoke test your case. that will make any dead areas blatently obvious.

    well just some random off the top of my head.
     
  8. JamesHl

    JamesHl Supporting Actor

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    Front and side in, back and top out.
     
  9. Kevin P

    Kevin P Screenwriter

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    Power supply fans always blow out (exhaust), so for proper circulation fans in the rear of the case should also exhaust. Fans in the front should pull air into the case.
     
  10. Mark Shannon

    Mark Shannon Screenwriter

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    So seeing as the power supply fan already exhaust the warm air, I should have the fan at the front of my case blowing air in (with a filter, of course... BTW, where would I get one of those), and allow the power supply fan to expell it?

    Also, since i don't have a spot at the rear for a fan, should I get one of those PCI or ISA mounted fans? Having that exaust, and the front one blowing in would do the same job, rite?
     
  11. Adam Bluhm

    Adam Bluhm Supporting Actor

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    Those pci slot fans do nothing but make noise. I wouldn't look into them any longer.

    If you're having no overheating problems, consider no case fans at all. [​IMG]
     
  12. Chas_T

    Chas_T Supporting Actor

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    Mark,

    To answer your question on where to buy cooling fans.

    I've done biz with this company (The Card Cooler) and they were very good on shipping and price a few years ago. The market changes, so you'll need to do some research.

    This company is in the states and I don't know if that is problematic for you. There are many other sites to do business with on the net who sell this type of stuff.

    http://www.thecardcooler.com/

    I would agree with Adam if you do not have problems with overheating, why spend the money? Also, the more fans you install in the box, the more noise you will incur.

    I bought a Gateway 700XL about 18 months ago and added two extra fans to the box as the MB and the chip fried after less then a month. Another contact had the same experience with the same machine.

    I cannot blame it on overheating as it could been just electronic failure NOT due to heat. The box came with one fan on the power supply in the stock system. Rather then take any chances, I installed an 80mm and a PCI slot fan, which is rather quiet and does move air. One of the things I did, was place this PCI cooling fan close to the video card which I think helps keep that component a bit cooler. I can't verify it as the V-card does not have any temp monitoring devices.

    Also, I installed Mother Board Monitor to assure the box was within cooling specs. The 2 extra fans dropped the temps significantly.

    http://mbm.livewiredev.com/

    Also, I do not have a fan in front of the case with the filter as there is more then enough air circulation without it. My overclocking days are over!!!!

    Also, I would recommend if you install fans, to clean your box out on a regular basis with a can of compressed air. Depending on your living enviornment, PC's can be major dust collectors. Pet hair if you have animals have been known to collect in there too!! [​IMG]

    Much Luck!!
    Charles
     
  13. Mark Shannon

    Mark Shannon Screenwriter

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    WEll I have two computers, one of which doesn't run so great. We needed to replace the fan on that one, so I figured, why get one fan, when you can get two at twice the price (guess what movie that's quoted from...). The fan I added to my better computer does not add any extra noise at all, so it doesn't really bother me. Also, it just gives me better peace of mind...

    Chas, placing the PCI fan near the video card sounds like a good idea. I don't have one, but I've seen some new video cards that have fans built right onto them, and require them to be powered also from the power supply.

    Along with my Asus motherboard came a program called AsusProbe. It easily monitors both my CPU and MB temperature, as well as the CPU and Case fan speeds. It also can monitor the Power Supply fan speed, but there's no way to connect my power supply fan to the motherboard, so it gives no readings on that. Weird...
     
  14. John_Berger

    John_Berger Cinematographer

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