Construction and Acceptance Phase Commissioning
Construction-phase Cx is about verification with evidence. The CxA reviews submittals and shop drawings for OPR/BOD compliance, holds a commissioning kickoff, and monitors installation through site observation and pre-functional checklists completed by installing contractors. Pre-functional checklists verify static conditions: equipment is installed per manufacturer instructions, labeled, powered, and controls are point-to-point checked.
Then come functional performance tests (FPT), which demonstrate dynamic, system-level performance under actual or simulated conditions. Know the sequence: pre-functional checklists, then startup by the manufacturer or contractor, then CxA-witnessed FPT, then issue resolution and retest. Traps include accepting contractor test reports without CxA witness, running FPT before pre-functional checks are complete, and letting issues be verbally resolved without documentation.
The issues log is central: every deficiency gets an ID, description, responsible party, target date, and status, and stays open until verified corrected and retested. Acceptance also requires training, systems manual, as-built documentation, and a seasonal or deferred-testing plan for systems that cannot be fully tested at the current conditions.
Rule of thumb: no evidence, no acceptance. Worked example: a contractor reports an air-handler passes. The CxA checks the pre-functional checklist is signed, then witnesses FPT measuring airflow against design, verifying economizer changeover and alarms. If one value is off, an issues-log entry is opened and the test is repeated after correction.