This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later.
The ASHRAE 90.4-2025 version marks a significant evolution in the standard’s mission:
: The purpose now includes monitoring greenhouse gas (GHG) emissions , water consumption , and overall environmental impact alongside energy use.
Achieving compliance with the latest version of ASHRAE 90.4 requires a holistic design philosophy from day one. ashrae 904 pdf upd
: New language supports future inclusion of broader decarbonization and resource impact considerations.
: Recent updates often refine the maximum allowable values for MLC to reflect improvements in cooling technology and higher efficiency expectations in modern facility design. Accessing the PDF
, ASHRAE frequently releases addenda that are later integrated into the full triennial publication. ASHRAE 90.4 created to boost data center energy efficiency This public link is valid for 7 days
To ensure you have the legally compliant and most up-to-date version, you should download the PDF from the official source.
ASHRAE Standard 90.4 was first published in 2016 as a companion to the famous (Energy Standard for Buildings Except Low-Rise Residential). While 90.1 covers most buildings, 90.4 focuses exclusively on data centers – recognizing their unique IT equipment loads, cooling demands, and 24/7 operation.
Historically, data center cooling design was shackled to rigid prescriptive metrics (e.g., specific economizer hours). The updated 90.4 standard refines the Mechanical Load Component (MLC) calculations. Can’t copy the link right now
: Evaluates the efficiency of cooling systems, including fans, pumps, and heat rejection equipment.
In alignment with global Kigali Amendment targets (phasing down HFCs), newer updates to Standard 904 now require users to include the cost of future refrigerant replacement or decommissioning. Older PDFs ignore this, leading to artificially low LCC for high-GWP refrigerants.
| | Answer | | :--- | :--- | | How do I correct the typo to find the right document? | Always search for "ASHRAE 90.4-2025" (use a decimal point, not three numbers). | | Is there a "904" standard on the ASHRAE site? | No. The only similar title is "ASHRAE 90414-2004" for high-rise building HVAC. | | What is the cost of the PDF? | Prices vary but start from $9.00 for a single-user PDF, with multi-user licenses available. | | Does it apply to my facility? | It applies to data centers with a conditioned floor space power density greater than 20 W/ft² and IT equipment loads greater than 10 kW . | | What is a "Redline" version? | A redline version visually shows all changes made between the 2025 edition and the previous (2022) edition, making it easy to identify updates. |
Requirements for UPS efficiency and distribution pathway losses. Important Resources