ASHRAE TC 9.9 Overview

 

Liquid Cooling Classifications For Data Centers

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ASHRAE TC 9.9 defines different liquid cooling classifications for Data Centers based on facility water temperature available for cooling. The colder facility water would require higher upfront capital for the required cooling in terms of equipment and operating cost of chiller, cooling tower etc.

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The warmer facility water would help alleviate the concerns of upfront capitol on primary side cooling but it leads to other important factors to consider such as IT equipment max. temperature and also the approach temperature you have to live with. If approach temperature is constant, and the IT equipment can run at elevated temperatures, then CDU thermal capacity remains the same across the DC facility water temperature range.