I have came across a paper which says even if the white spaces(data halls) in a data centre building constitute the majority area of the project, the system selection for white spaces can be system 3 or 4 (As per the exception in ASHRAE 90.1 2010 - G3.1.1) and the supporting offices and mechanical rooms can be system 8.


(Refer Page 2, Column 2, Paragraph 1 of the above link)

So what should be the ideal approach, should I be selecting system 8 for baseline as per appendix G ? or can I go with system 4 for white spaces as per this paper? Is there any LEED or ASHRAE judgement for this matter? In my case, around 70%-80% of the building area are white spaces.

Any help on this would be appreciated, thank you.