Pre-Functional Checklist Dispute on an Air-Handling Unit
A 12-story office renovation has 38 air-handling units. The mechanical contractor submits pre-functional checklists for AHU-7. The CxA reviews them and finds: fan rotation verified by "observed," filter differential pressure gauges installed but not zeroed, damper actuators stroked but linkage set screws not torque-checked, and a note that the VFD was "factory set, no field adjustment needed." The contractor's commissioning agent (a separate party) signed off. The project schedule shows AHU-7 must start serving tenant spaces in 9 days. The contractor argues the CxA is "adding scope" because the specification only requires the checklists to be completed and signed. The specification does, however, require that pre-functional checks verify installation and start-up readiness before functional testing.
1. Which checklist items should the CxA reject, and on what basis?
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The CxA should reject items that are asserted rather than verified. "Observed" fan rotation is acceptable only if it records direction and method; if it merely states observed, it is not evidence. Filter differential pressure gauges that are installed but not zeroed cannot provide a trustworthy baseline, so zeroing must be completed and recorded. Damper linkage set screws that were not torque-checked are a latent failure risk; the check should require verification of tightness and full stroke without slip. The VFD claim that "factory set, no field adjustment needed" is not a pre-functional verification; the field settings, parameters, and safeties must be confirmed against the design and the manufacturer's requirements.
The CxA is not adding scope. The specification requires verification of installation and start-up readiness. A signature on an unverified checklist does not satisfy that requirement. The CxA should issue a written rejection listing each deficient item, the evidence required, and the resubmittal date.
2. The contractor says the 9-day tenant start date is at risk. How should the CxA respond without simply relenting?
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The CxA should separate the schedule problem from the acceptance decision. The CxA can offer to re-review a corrected checklist within 24 hours of resubmittal, and can prioritize the deficient items so the contractor knows exactly what to fix. The CxA should not sign off on unverified work to protect a date; that converts a schedule problem into a performance and warranty problem.
The CxA should notify the owner's project manager in writing that the tenant start date depends on the contractor completing the pre-functional items, and should state the earliest realistic acceptance date based on resubmittal and review. If the owner chooses to allow temporary occupancy before acceptance, the CxA should document the conditions, the outstanding items, and the plan to complete them, and should confirm that life-safety systems are not among the deferred items.