Heat gain to an airstream?

[kingherm]

Hi all, does anybody know how one would go about calculating the heat gain to an airstream due to the motor and fan being in the airstream? i am told that in many cases it could be quite significant, is this true? any help in this regard would be much appreciated....

 

[trashcanman]

Check ASHRAE Handbook of Fundamentals, calculating heat load, internal gains. Essentially, for a motor in the airstream, it amounts to the full KW draw of the motor x use factor (how much is the motor running?). For a motor running 1/2 the time, use factor = 0.5. Usually amounts to 1.5 to 3 Deg temp rise.

 

[MintJulep]

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