A quick internet search sometimes yields references to "ASHRAE 904" – this is likely a confusion with:
There is no ASHRAE Standard 904. Professionals should always reference ASHRAE Standard 90.4 when discussing data center energy standards. ashrae 904 pdf upd
The latest ASHRAE updates increasingly align with the White House’s Interagency Working Group on the Social Cost of Greenhouse Gases. A modern "UPD" PDF will include optional (or mandatory) environmental life cycle cost (ELCC) parameters, monetizing CO2e emissions. A quick internet search sometimes yields references to
Compliance is achieved by demonstrating that the facility’s design PUE is less than or equal to the allowable PUE from the standard’s tables. The design PUE is calculated as: There is no ASHRAE Standard 904
PUE_design = (IT Load + Cooling Load + Power Distribution Losses + Lighting + Ancillary Loads) / IT Load
Where: