I am working on a Data Center project which is located in Zone 4A. the project is assessed based on C&S. I am confused about the baseline building system selection.

As expected the is predominantly a data center (computer room based on ASHRAE 90.1 definition) there are some office areas and support facilities with significantly lower loads. Am I interpreting the ASHRAE guideline correctly to not include exception “c” and “g” and determine the system based on total conditioned areas.

If the first assumption is correct based on total conditioned area, system 7 should be chosen. Then I wonder if I could exclude economizer from the baseline building as based on section G3.1.2.6.1, economizers should only be applied to System 11.

System 11.