Construction-Phase Commissioning and Installation Verification
Construction-phase commissioning is where the CxA verifies that installed work matches the design intent and is ready for functional testing. Core activities include the Cx kickoff meeting, submittal and shop drawing review for commissioned systems, witnessing of startup, review of contractor-completed pre-functional checklists, and installation verification.
Pre-functional checklists confirm static conditions: equipment is installed per manufacturer instructions, labeled, accessible, wired correctly, and safe to energize. They are completed by the installing contractor and verified by the CxA. Functional performance testing then confirms dynamic operation. The trap is accepting checklists at face value - the CxA must spot-check and require evidence (photos, readings, signed verification). Another trap: confusing startup (manufacturer/contractor activity) with functional testing (verification of integrated system performance).
Installation verification includes checking clearances, vibration isolation, pipe and duct insulation, sensor placement, valve and damper stroke, controls wiring, and labeling. Sensor location errors are a classic hidden defect that later corrupts control and testing.
Rule of thumb: no functional test begins until the associated pre-functional checklist is complete and verified. Worked example: a CxA finds a duct static pressure sensor installed downstream of a turning vane in a turbulent location; the reading is erratic, so the checklist is rejected until the sensor is relocated per design, preventing a false functional test failure.