What needs to be taken into consideration when calculating the PUE?

A data center has its own power supply from the public utility and receives chilled water supply from

the building owner.

What needs to be taken into consideration when calculating the PUE?
A . Nothing, as the chiller plant in the building also uses electrical power
B . You will need to take the value for COP of the chiller plant into consideration
C . You will need to take a weight factor of 0.4 for district chilled water into consideration
D . PUE calculations are not possible in shared buildings

View Answer

Answer: C

Explanation:

When calculating Power Usage Effectiveness (PUE) in a data center that uses chilled water from an external source, like from a building owner, a weight factor for district chilled water must be applied. This is because PUE calculations aim to measure the energy efficiency of the data center’s own operations, and external utilities like district chilled water aren’t directly powered by the data center. A weight factor of 0.4 is typically used to account for the energy consumed to produce and deliver the chilled water, reflecting the indirect impact on the data center’s total energy consumption .

Detailed Explanation

PUE is calculated as the ratio of the total facility energy to the IT equipment energy. If the cooling is provided by an external chilled water source, it’s necessary to adjust the calculations to accurately reflect the energy impact. By incorporating the 0.4 weight factor, data centers can calculate a more accurate PUE, aligning with standard methods and industry best practices.

EPI Data Center Specialist References:

EPI training on PUE highlights the importance of adjusting for external energy sources, such as district cooling, in the calculations. This ensures that PUE values remain accurate and comparable across different data centers, even when external utilities are used.