### Asset Description:
Chiller: A device that removes heat from a liquid through a vapor-compression or vapor-absorption refrigeration process. The cooled liquid can then be used to cool equipment, buildings, or other systems.

### Conditions:
- Chiller Running
- Supply Temperature - Setpoint Temperature > 5 °F

### How long the conditions were met:
Met for 2 Hours

If you were to advise the operator, which option should they prioritize, based on the conditions?
A. Hand or overridden on when the supply fan is off
B. System is not designed well for part loads on the chiller
C. Vanes at wrong angle
D. New energy use or equipment that has been removed


# Answer

Answer: B. System is not designed well for part loads on the chiller

Guidance Rationale:

The chiller is actively running, yet the supply temperature
exceeds the setpoint by more than 5 °F, and this condition has persisted for 2
hours. This sustained gap indicates that the chiller is unable to meet the
cooling demand, despite being in operation. Such a discrepancy is often
associated with inefficiencies at partial load conditions, where the chiller’s
performance drops due to poor part-load design characteristics. Rather than a
control override, airflow issue, or recent equipment change, the symptoms point
to a system design limitation, where the chiller is not optimized to operate
efficiently at lower or varying loads. 

Option A, "Hand or overridden on when the supply fan is off," suggests a manual intervention that is unlikely to be the
cause of a persistent temperature discrepancy over a 2-hour period. Option C,
"Vanes at wrong angle," implies an airflow issue, which is less likely to cause
a significant temperature difference in a chiller system. Option D, "New energy
use or equipment that has been removed," suggests a recent change that would
typically result in a sudden and noticeable impact rather than a sustained
issue. Therefore, the operator should prioritize investigating the system’s
part-load performance, as the most likely issue is: "System is not designed well
for part loads on the chiller."