Design changes during the implementation phaseare generally allowedonly when there is a strong business and/or technical justification. Changes at this stage can lead to delays, increased costs, or compromise design integrity. Thus, a rigorous assessment is required to ensure any modifications are essential and provide clear benefits or address critical issues.
Detailed Explanation:
Changes post-design freeze should be minimized to avoid scope creep and additional costs. However, if a technical issue arises that would affect operational goals, or a business need warrants modification, justified changes are permissible, following an impact assessment and approval process.
EPI Data Center Specialist References:
EPI project management guidelines recommend a controlled change management process during implementation, allowing changes only when they align with critical objectives or address unforeseen issues that affect the project's success.
Question # 18
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
When calculatingPower Usage Effectiveness (PUE)in a data center that useschilled water from an external source, like from a building owner, aweight factor for district chilled watermust 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 of0.4is 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.