: While Standard 90.1 covers general buildings, 90.4 is the specialized "sister" standard designed for the unique high-density loads of data centers (typically defined as spaces with IT loads >10kW). Compliance Metrics :
ASHRAE 90.4 PDF Update: Navigating the 2025 Energy Standard for Data Centers ashrae 904 pdf upd
The represents a mature, data-driven evolution of the only PUE-based energy code for data centers. By accounting for real-world redundancy, updated climate data, and emerging cooling technologies, it balances energy efficiency with operational reliability. For any professional involved in data center design — and for those mistakenly searching for "ASHRAE 904" — this standard is now essential reading. : While Standard 90
Recognizing that 2N or N+1 cooling architectures inherently consume more energy, the 2022 edition allows a for facilities with full redundancy. For example: For any professional involved in data center design
: The "incoming service segment" was removed from Electrical Loss Component (ELC) calculations because it was a minor factor that designers often could not control.
The 2022 revision responds to three industry shifts: