An air-conditioner unit needs to be selected.

From anefficiency standpoint,Unit Bwith aSensible Heat Ratio (SHR) of 0.9is preferable. A higher SHR indicates that a greater proportion of the air conditioner's capacity is dedicated tosensible cooling(temperature reduction) rather thanlatent cooling(moisture removal). In data centers, sensible cooling is more critical since IT equipment primarily generates heat without adding significant moisture.

Detailed Explanation:

An SHR of 0.9 means that 90% of the cooling capacity is used for sensible cooling, which is more efficient for environments like data centers where humidity control is typically less of a concern. Opting for an air conditioner with a higher SHR ensures that most of the cooling energy is focused on temperature reduction, making Unit B more efficient in this scenario.

EPI Data Center Specialist References:

EPI data center best practices recommend choosing cooling units with higher SHR values in datacenters, as they better match the cooling needs of IT equipment. High SHR units improve cooling efficiency by concentrating on sensible heat removal, which is vital for maintaining the optimal thermal environment.