What is meant by a system's baseline data?

• A. A Record of All The System Performance Specifications When The System Is Operating As Designed
• B. The Last Maintenance Log
• C. The Refrigerant Charge Level
• D. The Maximum Pressure Rating

Answer: (A)

Baseline data is the reference set of measurements that defines how the system should perform under normal, design-operating conditions. It captures the key performance specifications—temperatures, pressures, energy use, refrigerant charge ranges, and other operating parameters—when the system is functioning as intended. Establishing this baseline during commissioning or after a major service gives you a yardstick to compare current readings against, so you can spot deviations quickly, diagnose problems, and track trends over time. This is the best fit because it directly describes a record of how the system should perform. It’s not the maintenance log, which documents service history rather than how the system should perform. It’s not just the refrigerant charge level, which is only one parameter, and not the overall performance reference. It’s not the maximum pressure rating, which is a safety limit rather than a performance baseline.