Cooling a 12" powerbook in clamshell mode

Discussion in 'PowerPC Macs' started by Chrispy, Sep 28, 2005.

  1. macrumors 68020


    Hey all. I was wondering if anyone else has issues with the fan kicking on all the time on their 12" powerbook while it is in clamshell mode hooked up to a 20" Dell Widescreen monitor? I'm not all that worried about it but would anyone recommend a good product for cooling the powerbook so its fans don't wear out? I know there are prodcuts you can put under the powerbook with fans that cool it but I was hoping somone could recommend a good one for me. Thanks!
  2. macrumors 68020


    I use my 15" PB in the clam shell mode on iCurve, while being hooked up with a 23" ACD. I have a clip on fan on my desk to give extra air flow. I occasionally run my 12" PB in the clam shell (but, mostly I set it up as a screen spanning with a 20" ACD) and I put my PB on the Targus coolpad (the one with 2 fans). This has been working well as it seems my PBs are not kicking up fan. Basically all of my notebook computers are positioned on the coolpads, iCurve, notebook podium.
  3. macrumors 68000


    cool, same setup i have. . . except i have the revA 12"PB which is notorious for being really really hot! i set it up on the base of the monitor (shown in the picture) but then i realized the back fan is too close to the tower supporting the monitor. so i moved the pb forward (until it leaned off the base of the monitor) and i am currently using four dollars to hold it up. (8 half dollar coins) and it holds it very well. just getting it off the table and allowing air to flow under it really helps keep it cool. so use the surface area of the PB to help it cool itsself. . . the only practical material that has a better conductive heat transfer coefficient is copper. . . and i dont think that would make a very good looking laptop! cause it would turn green and brown like pennies very quickly! anyway, the moral of my heat transfer story is to let air flow around (all sides) of the PB when it is in clamshell mode, and that will help keep it cool!

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  4. macrumors 68020


    Thanks for the tips all. I think I'm gonna get one of those lap things with the fans built into it, but for now I used some nickes to prop up the computer. See the pic :)

  5. macrumors 68000


    hmmm, nickles are cheaper than half dollars, maybe i should swap mine out, or maybe go for pennies. . . they are copper and would be better at conducting heat away from the PB. . . i guess the best though would be to get silver coins. . . silver has a much better heat conductivity than all the other metals mentioned, but i think generally coins are made with copper centers and only coated with silver (if they are silver) (so coated with nickel if they are nickles or other coins) hmm, i think i shall propose this to my heat transfer prof. (yes, i am a mechanical engineering student taking a heat transfer class, thats why my postings sound so odd. but interesting to me :) ) hmmm. . . i know apple's site shows the maximum power usage of the PB . . . does anyone know what aluminum compound apple uses for the shell of the PB?
  6. macrumors 68030

    Simplest method: Don't keep it closed. The keyboard acts as a ventilation outlet. If you block that, then of course heat will build up and the fans will start screaming.
  7. macrumors member

    I have my 12"1ghz rev b pb on the koolsink stand and running in clamshell mode, no problems with heat whatsoever and the fans never turn on.
  8. macrumors 68020


    What is this koolsink stand you speak of ;) I would love to see a pic or a link as it sounds like it is working out great for you. Thanks!
  9. macrumors 68000


    apple designed the powerbook to be able to run with the screen closed. its all aluminum, its essentially a giant heat sink!! the iBooks on the other hand should NOT be used closed. and apple does not allow them to be used closed, yes there are hacks to get around this, and yes, i used one when i had an iBook, but it is a very bad idea with the iBook. But due to the thermal properties of the PB the PB is fine when closed. its actually good to save the backlights on the PB if you used to closed and hooked up to an external monitor!!
  10. macrumors 68030

    I dunno. I'm aware of what Apple intended. I just don't think it's a good idea to have heat build-up and expanding metal too close to the screen. The backlights stay off with the lid open BTW. This is how I hook up my PB.
  11. macrumors G5


    There was a time in the "mid Panthers" when my PB fans would run a lot with Folding@Home. I just propped up the rear about an inch. A couple objects under the feet works fine--or in my case, a 3-edge ruler did the trick.
  12. macrumors 68020


    Apple did design the powerbook to operate with the lid closed. That is why it supports clamshell mode. Also, if you run with the screen open then you only get 32MB of graphics memory on the external screen and not the full 64MB.
  13. macrumors 68020


    Man.. the problem almost seems to be getting worse. The fans run ALL THE TIME now. In addition, they are running full blast as if the computer is over heating. The room is cooled by an air conditioner so it never gets hot in the room where the computer is located... I'm getting a little worried about it to be honest :confused:
  14. macrumors 68020


    I just ran temperature monitor and none of my readings are close to being at their limit... seems strange that the fan is running near full blast.... I am very confused.
  15. macrumors member

  16. macrumors 6502a


    i dont know about your powerbooks but on my ibook I can leave it cracked open about an inch but it thinks its closed and when i run in clamshell mode i just have a fan which blows across the keyboard, you guys could do that or you could find where the reed switch for your powerbook is and stick a magnet there to trick the sensor into thinking the powerbook is closed while its still open (info here)
  17. macrumors 68020


    The ideal thing to do would be to buy or build a vertical stand for it. I do this with my TiBook and it runs even cooler vertically with the lid closed than it does horizontally with the lid open. I've got it propped up like a thin little minitower next to my monitor.

    Heat rises. The fan blows air inward and out the sides. With the lid open, the heat can escape through the keyboard, but not when the lid is closed in a horizontal position. In a vertical position, the heat just gets blown out a side vent instead of escaping through the keyboard, plus, the whole bottom side of the machine can act like a big heatsink. If the room is drafty or you have a very gentle fan moving air around the room, that alone will do a great job cooling a vertically-oriented machine.
  18. macrumors 68040


    In the past, when I had the Powerbook operating this way, I opened the lid after a couple hours, and the keyboard/screen were not hot at all, even though the bottom of the Powerbook was quite warm. I don't think the heat comes up that way.

    The fans do their job.

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