I am currently carrying out an ASHRAE 90.1 appendix G baseline model
which is showing me 350 unmet load hours. There is only one zone with
the unmet load hours, having looked at the Space temperature summary
SS-O for the zone it shows the hours are occurring before the fan
schedule switches on the fan, but my understanding of the unmet load
hours are only counted when the system is active.

If anyone has come across this previously and came up with a solution, I
would be grateful for any advice.

Gary Chatfield