using fans to cool the iMAC 27 inch

Discussion in 'iMac' started by MorBrooks, Dec 6, 2010.

  1. MorBrooks macrumors newbie

    Dec 6, 2010
    Does it do any good to have external fans blow air into the vents at the bottom of the imac 27 inch? if these vents do not provide access to the main environment within the Mac and instead are totally isolated to the existing fans than any external air would be simply blown through the existing fans which could be counterproductive. Anyone have any information on this?
  2. MacHamster68 macrumors 68040


    Sep 17, 2009
    you could blow in air under the side of the optical drive as the internal fan there is a bit further up ,
    but ideally would be to drill a 80mm hole about where the harddrive sits (middle upper 3rd of the iMac) and fit a 80mm extractor fan to get the hot air out of the iMac instead of blowing cool air in , because you still got only this tiny slot on top where the hot air might find a way out eventually :rolleyes:
  3. TMRaven macrumors 68020


    Nov 5, 2009
    The iMac was already cleverly designed by the engineering team of apple to be adequately cooled within reason. If you're fretting over the temperature of its internals so much, you could just merely raise the rotational rate of its internal fans a couple hundred rpm using smc fan control. The result should be much less intrusive than using external means.
  4. aki macrumors 6502a

    Mar 2, 2004
    I concur with the view expressed by TMRaven. The internal architecture is cleverly designed and drilling holes and adding fans may actually make things worse if it messes with the internal airflow design.

    A less invasive and more sober strategy at least to start with would be a software fan management solution like smcfancontrol.
  5. MacHamster68, Dec 6, 2010
    Last edited: Dec 6, 2010

    MacHamster68 macrumors 68040


    Sep 17, 2009
    under normal circumstances i would agree , but as every other thread here is about loud fans and such ,it would be pointless to raise the fans speed as they would then be even louder ,and if the iMac would have been so clever designed as some point out , why would it then be necessary to raise fan speeds
    so yes i agree the imac is clever designed , the problem is with aluminium that it acts in case of the iMac's case as a giant heatsink , so it is supposed to get hot ,which leads most people to the conclusion their iMac is constantly overheating , so they start messing about with fan controls

    i would suggest to install temperature monitor which as its name suggests monitors the temperature of all parts inside with a temp sensor and it shows the the actual temp and the max temp the individual part should reach before the fans are supposed to kick in full blast , and as long as your iMac runs below these limits its perfectly fine and you should not need to alter any settings , and if exceed the limits constantly , then its time to clean it inside of dust or bring it to apple as it has a defect if its really overheating
  6. mulo macrumors 68020


    Aug 22, 2010
    Behind you
    just have a fan blow on the back of it, the entire thing is a heatsink....
  7. product26 macrumors 6502a


    May 30, 2005
    Perhaps some sort of adhesive aluminum heatsinks on the back? Could be executed well with good design.

    Or heat pipes adhered all the way up the back with rows of aluminum fins connecting them at the top over the exhaust vent. That'd probably pull the extra heat directly in to the air.
  8. MindlessJD macrumors member


    Apr 19, 2006
    Hampshire, UK
    Surely raising the RPM by a small margin wouldn't make that much of an audible difference. My 27" i5 is very quiet and to be honest, I don't think it gets that hot under general usage as it is...
  9. MorBrooks thread starter macrumors newbie

    Dec 6, 2010
    Thank you all for your responses

    Well, as it turns out, I downloaded the SMC Fan Control utility. I set my minimum fan speed at the halfway point for all three fans (yes you can definitely hear the fans now) and saved my setting with the appropriate name of "gamming". Now comes the sweet part. With having increased the fan speed and doing a restart (not a shutdown) and loading my bootcamp partition (windows 7), the fan speed settings remained and with loading Metal of Honor, the mac operated totally cool. the aluminum casing was slightly warm at best. Yes there is the fan noise, but my speaker system (or if I wish, my headphones) did effectively drown out any fan noise.

    Again, thanks to all for your contributions and I hope my experience will help benefit some of the other Mac Users who LOVE playing windows based games on a teriffic hardware (backlit LED medal of honor is awesome) platform.
  10. TMRaven macrumors 68020


    Nov 5, 2009
    Yeah it's great how smc fan control carries over to windows. I use it to overclock my mobility 4850 to desktop standards from time to time when I game.
  11. ferrarofilms macrumors member

    Oct 27, 2008
    Overheating in summer

    Now we are in summer here in Australia and the room temperature is 26-27 celsius, my Imac Quad 2.93, 8GB ram and 1Gb graphics gets HOT and if I do not put and external fan against the aluminum back it simply hangs, it is not a matter of a few degrees, it is a massive warming, to big problems...big remedies...
    ....and no way I can put an AA, electric bills here can kill you....

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