Side panel fan question

Discussion in 'General Hardware' started by DoNuTjC, Mar 8, 2003.

  1. DoNuTjC

    DoNuTjC OSNN Addict

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    I just put a window on my side panel with 2 92mm fans... should this fans be intake fans or exaust fans?

    thanks
     
  2. adamg

    adamg Guest

    In my experience exhaust fans do WAY more than intake fans. But you could probably have one intake and one exhaust.
     
  3. LeeJend

    LeeJend Moderator

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    Depends on how many intake and exhaust fans you already have.

    There is one exhaust for sure in the power supply. So you should have one intake also. Preferably low and towards the front of the case.

    A second exhaust should go high and towards the rear. Hope your cutouts match that...

    The reason the intake fans do so little is that they have too much pressure drop to deal with. i.e. you are trying to pump up your case and let the vents handle the outflow.

    Another problem can occur with too much exhaust capacity without adequate openings. You end up pulling a slight vacuum in the case and that hurts heat transfer.

    The ideal case would have the cpu, ram and video accelerator mounted low with an inlet fan and an exhaust fan moving air across the 3 from front to back. The power supply should be at the top away from the computer smarts.

    The current ATX standard is thermal idiocy. The design crams all of the heat sources (PS, HD, CPU, RAM and Video) together in the top of the case where the heat will further accumulate due to natural convectrion. Good design for an oven but idiocy for a high speed computer. This insanity resulted from some marketing genius deciding to set computers on their sides when the whole AT/ATX concept was devloped for horizontally oriented desktops, not for vertical towers.

    Wonder when someone will figure this out and come up with a decent case design.

    The HP toasters are do some good by puting the power supply outside of the case.

    The new "tool box" design is just more of the same mistakes with even less front surface area to allow adequate air intake.

    The best place to put your side cover fans would be inlet lower front and an exhaust upper rear (or middle if the power supply is in the way).

    If this sounds like I'm rambling, I am. I think I'm getting an idea for a new case design concept. It's just not quite there yet. A key will be intake fans on the bottom of the case and about 3/8 inch tall feet to let air get pulled in from underneath. That will solve the problem with large front air intakes letting out too much noise and provide plenty of room for inlet fan mounting. The top cover really needs an exhaust fan in it too, but then we're back to noise escaping and people dropping stuff into the case...

    BTW my side covers on my performance system are both solid and I added 1/8 inch of cork glued to them for sound deadening. I switched from a case with ventilated sides to this one because the side cover holes weren't doing any good. Adding the cork did not affect my case temperature. With the cork side covers the cpu and video card fans aren't really noticeable anymore.

    Over half the noise my system makes comes from the sound of air passing through the front bezel and inlet fan noise coming out of the bezel. The rest is fan noise from the rear exhaust fan and power supply fan. I can drop the noise level in half by putting a sheet of cardboard about a half inch in front of the inlet bezel.
     
  4. Smokie

    Smokie A Proud Australian

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    I have a Lian Li case which I fitted two 80mm fans to the side window. I have positioned one fan as an intake directly over the cpu fan which has helped keep the cpu cooler.

    The second fan is fitted as an intake directly over the video card, helping with the cooling as well.

    I have an 80mm exhaust fan at the back and also an 80mm exhaust fan on the top of the case plus the two in the power supply and the two 80mm intakes in the front of the case.
     
  5. Zedric

    Zedric NTFS Guru Folding Team

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    DoNuTjC: The important thing is to get a decent balance between inflow and outflow. Also a well defined air stream from intake to output will help you (one of the reasons I don't really believe in side panel fans, but that's ju me :)).

    The thing you should not do is have one intake and one blow out if they are close to eachother. This will cause most of the air to go in through the first and then directly out through the other leaving the airflow somewhere around the zero mark.

    One idea would be (if you're up to it) to make a tube from one the fans (intake) on the panel to the top of the CPU heatsink. This way you always get cool air for the CPU.

    LeeJend: I'm thinking about some new case designs as well. I haven't gotten too far though... :) Something effective to get rid of this fan mania of todays computers. And hopefully another case made for watercooling.
     
  6. Jz1397-5

    Jz1397-5 XP Bad Ass

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    have both blowing in and the two in the back blowing out.
     
  7. LeeJend

    LeeJend Moderator

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    Zedric

    Better be careful. IBM will get you for patent infringement. My computer at work (yucky 633 P3) has a plastic shroud that runs from the front fan directly to the CPU. Only time I've seen that done.

    I'm toying with a cardboard u channel diflector to do the same thing with my intake fan. Aim the air upwards onto the cpu or video. Problem with blowing on the video is there is no exhast port behind it. I could pop a pci slot cover but random openings have not helped much.
     
  8. Zedric

    Zedric NTFS Guru Folding Team

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    Nah, Dell use the shroud as well. But that goes from the CPU to the back fan.

    I was thinking plastic plumming pipes or a flexible ventilation pipe. They should be about 80mm right? *guessing wildly* :D

    The video card is really a problem. It has the heat source on the underside of the card which is just bonkers. The GF FX solution is one of the better (except for the f*ckin noice!) there IMHO.

    I saw a water cooling kit somewhere with a shroud covering the bottom of the case so that air comes in through the front, goes through the radiator and out the back through a PCI slot. No hot air in the system there. :)

    Top side blowholes are nice. As long as you have some space above the case anyway.

    (Why did I pick this thread for going on about cooling? :confused: )

    :)
     
  9. busto

    busto Guest

    What if you put a intake blowhole on top and then a side exhaust on towards the bottom, would that work ok?
     
  10. DoNuTjC

    DoNuTjC OSNN Addict

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    well my case has... 2 80mm intake fans in front, one exaust fan in back and one exaust fan ontop which get block from wires that I can't seem to cleam up even with some loom... but now I have the side with 2 92mm fans which I'll put as intake...

    thanks guys
     
  11. Maveric169

    Maveric169 The Voices Talk to Me

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    Well I just got done (yesterday) with my case mod, I will post pics when I can get my camera to work right, but what I did was this.

    I cut out a 92mm hole in the front bezel, and the front chassis, and mounted a 92mm w/ air filter. I cut out the 80mm hole in the back of the chassis where my 80mm exaust fan is mounted. And I cut a 120mm hole in the top of the case and mounted a 120mm fan. I also have an air vent in the front, top of the case to prevent a vacum condition.

    I really wish I could say that it made a great difference in my temps as I had hoped but nothing more than a 3C drop in my case temp and 1C drop in CPU. But I really don't think that the temps are reported correctly. I think I may have reached the limit in what I can do with air cooling. :confused:

    As far as a side panel fans, i would say go with intake, and check your temps. write them down after 10 mins. Then change 1 to exaust and check the temps after 10 mins. Then set them both to exaust and check the temps after 10 mins.

    I really don't think that setting 1 to intake and 1 to exaust will help at all if there are less than 4 inches apart, as you would only be circulating the air the blowing depth of the fans, but with that said you will most likely be blowing enough air with 92mm fans to hit the motherboard and components. So it is a toss up, really.
     
  12. Zedric

    Zedric NTFS Guru Folding Team

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    Really bad idea. Hot air rises. The other way around would be much better.