What action should an engineer take if most buildings are satisfied with chill water, except one?

Putting an additional chilled water pump online is a practical solution to address the issue of one building not being satisfied with the chilled water. This option suggests that the current system may be insufficient in distributing chilled water effectively to all buildings, possibly due to flow limitations or distribution challenges. By introducing an additional pump, the engineer can enhance the flow rate of the chilled water, ensuring that all buildings, including the one that is currently unsatisfied, receive adequate cooling.

This approach directly addresses potential operational inefficiencies in the chilled water system rather than assuming a complete system replacement, which could be more costly and unnecessary. Additionally, increasing the temperature of the chilled water would not solve the problem since it would likely worsen the satisfaction of the building's cooling needs. Isolating the unsatisfied building might reduce the load on the system temporarily but would not resolve the underlying issue and would leave the building without adequate cooling. Therefore, activating an additional pump stands out as a feasible and effective response to the situation.