Notices
Results 1 to 8 of 8

Thread: Heat Dissipation Question

  1. #1 Heat Dissipation Question 
    New Member
    Join Date
    Nov 2011
    Posts
    3
    Can anyone tell me how heat would dissipate in a room with the following scenario with using a PC:

    Scenario using exact same PC components except from PC 2 having a better aftermarket gpu cooler :

    PC 1 vents heat from a Gpu core at a temperature of 90c into an enclosed room.

    PC 2 vents heat from a Gpu core at a temperature of 65c(due to better cooling on the gpu core) into an enclosed room.

    I have been told that with both scenario's it would create the exact same ambient temperature in the room, where as I would have thought the 65c temperatures would cause lower ambient temps in the room because the cooler air could disperse quicker in the room than the hotter air.

    Thanks in advance for any light on the matter.


    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Professor wallaby's Avatar
    Join Date
    Jul 2005
    Location
    Australia
    Posts
    1,521
    Not that i know anything of GPU cooling, but i think the key lies in considering the heat generated by each PC and not the temperature of the GPU's. The heat extracted by the cooling system has to go somewhere and it seems like the only place it can be dumped is into the room, since both PC's produce an identical amount of heat this means the room will have the same ambient temperature.


    Reply With Quote  
     

  4. #3  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    Wallaby is correct.
    Reply With Quote  
     

  5. #4  
    New Member
    Join Date
    Nov 2011
    Posts
    3
    Thanks for the reply, but I'm still

    Quote Originally Posted by wallaby View Post
    i think the key lies in considering the heat generated by each PC and not the temperature of the GPU's.
    That's my thought, but when you say:

    Quote Originally Posted by wallaby View Post
    since both PC's produce an identical amount of heat

    Even though 1 PC is outputing 25c less hot air into the room than the other PC?

    Quote Originally Posted by wallaby View Post
    this means the room will have the same ambient temperature.
    I was under the impression as the hot air venting into the room is of a lower temperature than the higher 90c, the original cooler ambient air (I live in Scotland and as it's cold, surely the vented air cools down quicker) would be able to cool down the 65c hot air quicker as they mix together.

    I presumed the 90c vented air would find it harder to cool down the ambient room temps as it would increase the ambient temps quicker.

    Regards, tommy
    Reply With Quote  
     

  6. #5  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,822
    The room is being heated by the stream of heated air from the computer. The rate of room heating is proportional to both the temperature difference above ambient, and the flow rate of the stream of heated air. A high flow rate of warm air can achieve the same heating effect as a slow moving stream of hot air.
    Reply With Quote  
     

  7. #6  
    Comet Dust Collector Moderator
    Join Date
    Mar 2011
    Location
    New Jersey, USA
    Posts
    2,848
    Now that we're into fall/winter, I've allowed my BOINC projects to run longer. In summer, when AC is required, I throttle them way back.
    Reply With Quote  
     

  8. #7  
    New Member
    Join Date
    Nov 2011
    Posts
    3
    Quote Originally Posted by Harold14370 View Post
    A high flow rate of warm air can achieve the same heating effect as a slow moving stream of hot air.

    I realise that the flow rate of the same temps can be equall but for talking sake, if both the rate of air were roughly the same, wouldn't the lower temp provide lower ambients?

    Quote Originally Posted by MeteorWayne View Post
    Now that we're into fall/winter, I've allowed my BOINC projects to run longer. In summer, when AC is required, I throttle them way back.
    That's what I can't get my head around, if the ambient is colder than the hot air output, I presumed the cooler hot air would cool down quicker than what the warmer air would.

    In the situation I'm talking about, I'm still confused on why a larger better conducting heatsink and fans that can reduce a gpu core from 90c to 65c, combined with colder ambient temps, can't reduce the temps in a room any better than the very hot running stock fan.

    I was planning on doing a Boinc project for Epidemiology but was advised about the temps the gpu reaches not only on the core but how the ambient temps increase, I presumed an aftermarket cooler with a better surface heat transfer/better fans would have sorted out both issues but it's looking like it's a no go now!

    Thanks very much for all the helpful replies.
    Reply With Quote  
     

  9. #8  
    Comet Dust Collector Moderator
    Join Date
    Mar 2011
    Location
    New Jersey, USA
    Posts
    2,848
    Basically, there's "x" amount of heat created. One way or the other it is transferred to the room. A higher air flow and heat sink rate keeps the innards of the pooter cooler and warms the room faster. A lower flow and less heat transfer makes the guts higher, and it takes longer to warm the room.

    In the end, the result is the same for the room, it's just a matter of moving the heat out faster or slower.

    By running BOINC less in the summer, I decrease "x", the amount of heat generated, so I need to run the house air conditioner less. In fall/winter, when I'm heating the house, the heat is not wasted, so I let it fly and try and increase the amount of heat and the transfer rate.

    For the same reason, I replace some CFL lights in winter with incandescents, since again, the heat is not wasted, and I don't have to pay to remove it. It helps.
    Reply With Quote  
     

Similar Threads

  1. Aluminium oxide dissipation in water.
    By pepsi_max2k in forum Chemistry
    Replies: 0
    Last Post: April 21st, 2011, 04:44 AM
  2. Specific Heat Question?
    By Deicide in forum Chemistry
    Replies: 1
    Last Post: February 4th, 2011, 01:51 PM
  3. Dissipation of potential energy in a waterfall
    By gonvaled in forum Physics
    Replies: 2
    Last Post: October 20th, 2010, 02:32 PM
  4. heat resistance question
    By rhysboi1991 in forum Chemistry
    Replies: 2
    Last Post: January 14th, 2009, 05:19 PM
  5. heat absorption question??
    By craig in forum Physics
    Replies: 4
    Last Post: April 28th, 2007, 09:01 AM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •