ASHRAE 90.4-2019

ASHRAE Standard 90.4 establishes the minimum energy efficiency requirements of data centers for design, construction, and operation and maintenance, and use of on-site or off-site renewable energy resources.The standard was developed to be code-intended, similar to Standard 90.1, and references in Standard 90.4 are made to Standard 90.1 for building envelope, service water heating, lighting, and other equipment criteria.

Key updates to the 2019 edition include:

* In Section 6, a reduction of the maximum MLC values required for compliance, and removal of the design MLC compliance path in favor of a more accurate maximum annualized MLC calculation

* In Section 8, a reduction of the maximum ELC values for the UPS segment required for compliance, made to recognize improvements in the efficiency of core electrical distribution equipment