Building codes (e.g., IECC, California Title 24) have begun incorporating 90.4 by reference. As of 2025, many U.S. states and international jurisdictions require 90.4 for new data centers over a certain size (e.g., 50 kW IT load or 500 ft²).
Imagine you are designing a 2 MW IT load data center in Atlanta, Georgia (Climate Zone 3A). ashrae 90.4 pdf