Q_ENTH contained in the .hrr file

[HEROISCOMING1]

Hello, I am a researcher conducting atmospheric modeling using FDS.
I am trying to use the Q_ENTH metric as an indicator to determine whether the model has reached spin-up.

Would it be reasonable to conclude that the energy within the model domain has stabilized when the Q_ENTH value converges to zero or becomes constant?

[drjfloyd]

If Q_ENTH is non-zero then you are on average increasing or decreasing gas temperatures in the overall domain. This would not be a steady-state condition.

If Q_ENTH is zero / oscillating around zero then on average temperatures are constant in the overall domain. In many cases, likely including your case, this would indicate steady-state conditions have been reached. However, you could have, for example, a geometry with two rooms where one room is getting warmer and one is getting cooler and the net is zero. In this case Q_ENTH being zero does not mean a steady-state condition.