ASHRAE TC 9.9
The industry committee whose A1-A4 air and W17-W45 water classes define the temperature envelopes IT gear can run in.
Current numbers
5th ed.ASHRAE TC 9.9 Thermal Guidelines edition introducing the liquid-cooling chapter and W-classes
A1–A4 / W17–W45ASHRAE TC 9.9 air classes and liquid W-classes (5th ed. + 2024 liquid-cooling resiliency addendum)