[Borisw37]

Hello,

I'm using FloThermXT to model an electronic enclosure that will be mounted outdoors.
One of the setup parameters is called "External Radiant Temperature".
Could somebody please clarify what that is?
Shouldn't it be the same as ambient air temperature?

Thank you,

Boris.

[piu58]

Originally Posted by Borisw37

Hello,

I'm using FloThermXT to model an electronic enclosure that will be mounted outdoors.
One of the setup parameters is called "External Radiant Temperature".
Could somebody please clarify what that is?
Shouldn't it be the same as ambient air temperature?

Thank you,

Boris.

The radiant temperature assumes that there is a body with the temperature to be given which is in radiation balance with the surface of the b.c. This may be very different from the ambient temperature.

Imagine or try out: Hold your hand in the near of a bulb. You feel the ambient temperature. Switch on the bulb. You feel the additional radiant temperature. If you switch off the bulb again you will determine that the ambient temperature did not change noticeable..

[Borisw37]

Thank you for the response. It all makes sense.
How do I determine what "typical" outdoor radiant temperature is?

[piu58]

Originally Posted by Borisw37

Thank you for the response. It all makes sense.
How do I determine what "typical" outdoor radiant temperature is?

The typical radiant temperature is the one of the air.

Differences are after sunset at clear night sky when surfaces cool faster than the air. Or warm walls at night - the wall cools much slower. If you think about it you find a few examples.