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Fan question

  1. Aug 4, 2011 #1
    If I have a typical Fan with a given CFM or even the outside diameter of the blade can I find the exIting temperature? Is there a formula out there to determine the exit temp.

    The fan is located in the middle of a room so we are not mixing in different temperatures.

    CFM, Dia of the blade, Inlet Temp.

    Exit Temperature

    My thoughts.
    1. Are my given conditions enough or will more factors be involved like pressure(atmpoheric[14.696 psi], etc..
    2. Common sense would think it would make the exit temp lower due to air being blow when a fan cools you down when standing next to it.

    Last edited: Aug 4, 2011
  2. jcsd
  3. Aug 4, 2011 #2

    By doing some more research I found out the Fan will not cool a person but cause a affect by only drying/evaporate moisture from the persons skin making it feel cooler called the brush temperature. Also it says it might raise the temp of the room because heat rises and if its a ceiling fan it will blow the heat downward.
  4. Aug 4, 2011 #3
    My problem is..

    1. If I have an outside environment of 15 C
    2. Inside environment of 30 Ft Dia. Circle = 2826 SF
    3. Heater 4Kw with a Fan 860 CFM

    what is the inside temperature going to be with this heater running.
    Last edited: Aug 4, 2011
  5. Aug 4, 2011 #4


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    Staff: Mentor

    You can't calculate the inside temperature without the heat transfer through the walls. The delta-T through the fan is 15 F, though...
  6. Aug 15, 2011 #5
    ok some updates:

    I have a fan going a Fan at 750 CFM blowing straight at a Finned Tube with a S/S enclosure with Holes in it directly in front of it.

    'FAN'(750CFM)---> blowing over 'Finned Tube'(Fins and Tube@4kW)-->Blowing out of a S/S Heater guard with holes in it. I nned to find the exit temperature is my concern..???

    It seems like a forced convection problem but I am not finidng the right information to solve it.
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