Ashrae 90.4 Pdf Jun 2026

The ELC ensures that your power delivery path (from utility meter to the IT rack) does not waste excessive energy as heat.

Measures the efficiency of the power distribution system, from the service entrance to the IT equipment. Key Resources & Access Official Document: The full standard, including the latest version, can be purchased as a PDF or hard copy through the ASHRAE Bookstore Read-Only Access: ASHRAE provides a Free Preview

Understanding ASHRAE Standard 90.4: The Blueprint for Data Center Energy Efficiency

This limits losses from the utility feed all the way to the server rack. This includes UPS losses, transformers, and PDU inefficiencies. If your UPS is 5+ years old, you might already be failing this requirement.

If your calculated MLC ≤ the table allowance → You comply. If it exceeds → You must redesign (add economizers, higher efficiency fans, or liquid cooling). ashrae 90.4 pdf

Understanding ASHRAE Standard 90.4: The Blueprint for Data Center Energy Efficiency

You can download a PDF of ASHRAE 90.4 from the ASHRAE website:

Data centers are the backbone of the modern digital economy. However, their immense power consumption presents significant environmental and financial challenges. To address this, the American Society of Heating, Refrigerating and Air-Conditioning Engineers developed .

ASHRAE 90.4 is increasingly being adopted into law. It is referenced by the and has been adopted by states like Oregon, Virginia, and Washington. The ELC ensures that your power delivery path

What are you planning to use (e.g., chilled water, direct expansion, liquid cooling)?

If you are designing a data center for a 10-year lifespan, you should download the current but also monitor the standing standard project committee (SSPC 90.4) for public review drafts.

The standard covers various aspects of data center design and operation, including:

ASHRAE frequently provides free, read-only digital access to its current popular standards for public review on their website. While you cannot download, print, or copy text from these versions, they are an excellent free resource for quick reference check-ins. A Warning Regarding Unauthorized Third-Party PDFs If it exceeds → You must redesign (add

The future of ASHRAE 90.4 is clearly aimed at a holistic approach to sustainability that goes well beyond simple energy efficiency. The forthcoming 2025 edition's expansion to include metrics for water use and GHG emissions signals a major shift in industry expectations. Designers can expect that future code cycles will not only require optimized PUE (Power Usage Effectiveness) but will also demand responsible water stewardship and verifiable reductions in the carbon footprint of the data center's operations. The standard will likely continue to evolve, incorporating new technologies like direct-to-chip liquid cooling and heat reuse, as it strives to enable the ever-growing demand for compute power within the constraints of a decarbonizing world. The overarching philosophy, as stated in the addenda documents, is that this standard is a consensus-driven document that will continue to set "practical and technologically feasible energy efficiency requirements for data centers on a consistent schedule."

If you are a professional engineer, architect, or data center manager, having the official or printed handbook is necessary for code compliance. Official Channels

As technology evolves, ASHRAE 90.4 adapts to address shifting industry demands: