I am curious about the uniform temperature environment example used in the Verification file radiation_2.in, downloaded from Github. The text in the V&V Guide, Section 3.4.2, states that this case models a furnace with a uniform temperature of 500°C. However, the input file, using the diagnostic parameter "DIAG" as shown below, uses F = 226.85. The Table in Section B.12 of the User’s Guide states the "F" parameter is in units of °C. While 226.85°C is equivalent to 500K, one might expect the room temperature to end up at 226.85°C (500K); but it results in room temperatures of 500°C. How does this work?

Say I want a room temperature of 500°C
So, I input an "F" value of 226.85°C (500K) and
The result is a room temperature of 500°C

It seems like the value selected for "F" should be the centigrade equivalent of the desired centigrade room temperature in Kelvin. For example, if I want the room environment at say 123°C, I set F = -150.15 or the centigrade equivalent of 123K.

This does seem to work but it doesn't seem to make sense. Can you please explain.

Note the "&MISC" command sets the room boundaries to be adiabatic. While this doesn't really pertain to the question above, it certainly pertains to establishing a uniform temperature environment.

Thanks in advance for your help.
Ray

Diagnostic parameter in radiation_2.in
&MISC ADIABATIC = .TRUE. /
&DIAG T = 0, 10000
F = 226.85, 226.85 /