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Warmer or Colder

  1. Nov 9, 2007 #1
    Imagine a perfectly thermally isolated room at 70 degrees Fahrenheit. A normal refrigerator that has some reasonable efficiency is brought into the room. It keeps the air inside of it at around 50 degrees or so. Will the room become warmer or colder? I think colder because the refrigerator will cool down the room more than the thermal energy it makes will warm the room.
  2. jcsd
  3. Nov 9, 2007 #2


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    Warmer. The energy taken out from the food inside is dumped into the room, plus the extra energy due to inefficiency of the motor, refrigeration process, etc.
  4. Nov 9, 2007 #3
  5. Nov 9, 2007 #4
    You can do a little experiment next summer. Put a window air conditioner in the middle of a closed room and turn it on. The room will get pretty warm.
  6. Nov 10, 2007 #5
    This would probably go better in the winter then huh! Hahahaha
  7. Nov 10, 2007 #6
    the room gets warmer because of 2 reasons, one we are giving in more energy to a system and also if we consider the room to be totally isolated then there is the principle of increasing enthropy( that is if we consider the generator for the refrigerator is in the room :P
  8. Nov 10, 2007 #7
    Alright thanks
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