Classification of PEM Room Loads with Shared Cooling System in Data Center (Process vs HVAC – PRM)

Hi all,

I’m working on a data center project pursuing LEED (PRM / Appendix G approach) and would appreciate guidance on classifying loads associated with prefabricated Power/Electrical Modules (PEM rooms).

These PEM rooms include equipment such as UPS systems, switchgear & transformers. The rooms are fully conditioned using CRAH units, with cooling provided by the same central chiller plant that serves the data hall.

My current approach is:

• The electrical equipment within the PEM rooms is treated as process load (non-regulated), modeled identically in baseline and proposed cases
• The CRAH units and central chiller plant serving these rooms are included as part of the HVAC system energy, and will also be modelled identical in baseline and proposed models with different meter than the rest of the building.

I would like to confirm the following:

1. Is it appropriate to classify PEM room equipment loads as process loads, even when they are served by the same cooling system as the data hall?
2. Have LEED reviewers accepted this separation of process load (equipment) and regulated energy (cooling system) in similar data center projects?
3. Are there any specific references (ASHRAE 90.1, LEED guidance, or reviewer interpretations) that explicitly address this type of configuration?
4. Any recommended best practices for modeling such spaces (e.g., zoning, load assignment, or avoiding double-counting between IT and electrical infrastructure loads)?

Appreciate any insights or experience-based feedback.

Thanks in advance.