Which elements are typically included in the chiller plant sequence of operation?

• A. Chiller sequencing, cooling tower operation, pumps, condenser water flow, economizer logic, and alarms.
• B. Only thermostat setpoints and zone control.
• C. Lighting controls and occupancy sensors.
• D. Exterior envelope performance.

Answer: (A)

Coordinating the main plant equipment to meet the cooling load efficiently and safely is what the chiller plant sequence of operation is all about. This sequence typically covers how chillers are sequenced and selected to run (including the order and redundancy), how the condenser water loop is managed through cooling towers and associated pumps, and how condenser water flow is controlled to maintain proper heat rejection. It also includes economizer logic, when used, to take advantage of favorable conditions and reduce mechanical cooling, along with alarms to alert operators to faults or abnormal conditions. Other options focus on non-plant aspects like thermostat setpoints in spaces, lighting controls, or exterior envelope performance, which are not part of the chiller plant's operational sequence.