Q: Is there a "Free" official ASHRAE 904 PDF UPD? A: ASHRAE is a non-profit, but it sells standards to fund research. There is no legal, "free" official copy except for students through university libraries (as noted above). Beware of torrent links—they are almost always obsolete.
Q: Does ASHRAE 904 apply to residential homes? A: Strictly speaking, Standard 904 is intended for commercial and industrial HVAC&R systems. However, the method can be applied to residential mini-splits or furnaces. For US residential tax credits, the HERS Index or Manual J/S is usually required instead. ashrae 904 pdf upd
Q: How often is Standard 904 updated? A: ASHRAE has a continuous maintenance process. Standards are typically reaffirmed, revised, or withdrawn every 5 to 8 years. However, addenda (smaller updates) can be released as often as twice per year. Q: Is there a "Free" official ASHRAE 904 PDF UPD
Q: My client requires LEED v4.1 compliance. Do I need the latest UPD? A: Yes. LEED references specific versions of ASHRAE standards. Check the LEED reference guide. However, using the very latest "UPD" is generally safer because LEED tends to adopt newer discount rate tables for Energy and Atmosphere (EA) credits. Beware of torrent links—they are almost always obsolete
The 2022 revision responds to three industry shifts:
Manufacturers and designers now have a simplified path for air-cooled chillers serving data centers: compliance with 90.4 automatically if the chiller meets 90.1’s integrated part-load value (IPLV) requirements and the facility’s cooling system uses variable-speed drives on all fans and pumps.