Ashrae 90.4 - Pdf

Historically, data centers were governed by , which dictates the energy efficiency of general buildings. However, Standard 90.1 relies on metrics like the Power Usage Effectiveness (PUE) , which divides the total facility energy by the IT equipment energy.

In a major step forward for the industry, the 2022 edition of the standard (and forthcoming 2025 updates) has been recognized as an alternate compliance path to the broader ASHRAE Standard 90.1 for large computer rooms, or data centers. This means that in many jurisdictions, data centers have a dedicated, performance-based standard tailored to their needs, rather than being forced to comply with rules designed for offices or retail spaces.

ASHRAE frequently provides free, read-only digital access to their current standards for public viewing on their official website. While you cannot download or print this version, it serves as an excellent reference tool.

The primary goal of the standard is to reduce the environmental impact of data centers without compromising their critical reliability [3]. It focuses on two main components of the infrastructure: Mechanical Systems ashrae 90.4 pdf

While ASHRAE 90.1 is the general energy standard for buildings, 90.4 acts as a specialized companion for data centers. What ASHRAE 90.4 does for data center energy efficiency

While traditional buildings follow ASHRAE 90.1 , 90.4 serves as its "sister standard," specifically tailored for the unique, mission-critical load requirements of high-density computing environments. ASHRAE 90.4 applies specifically to facilities where: Power Density is greater than 20 W/ft². IT Equipment (ITE) Load exceeds 10 kW.

ASHRAE Standard 90.4 provides specialized, performance-based energy efficiency requirements for data centers, utilizing Mechanical Load Component (MLC) and Electrical Loss Component (ELC) metrics. This standard allows for design flexibility, such as trading off efficiency between systems, and offers requirements tailored to specific climate zones. For more details, visit ASHRAE Releases Revised Version of Data Center Standard Historically, data centers were governed by , which

Mechanical engineers need the PDF to design cooling systems. Because 90.4 allows "performance-based" compliance, engineers use the tables in the PDF to simulate trade-offs (e.g., using a less efficient UPS if you install a highly efficient economizer-cooled CRAH).

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

Using economizers and high-efficiency cooling to meet strict PUE targets. This means that in many jurisdictions, data centers

Historically, data centers fell under (the code for standard commercial buildings). However, standard commercial buildings are designed for human comfort, whereas data centers are designed to house mission-critical IT equipment. Data centers operate 24/7, experience massive internal heat loads, and prioritize reliability above almost all else. Standard 90.4 was created to provide a code-enforceable document tailored specifically to these intense operational realities. ASHRAE 90.1 vs. ASHRAE 90.4: Key Differences

Chilled water pumps, chillers, cooling towers, computer room air handlers (CRAHs), DX units, and heat rejection fans.