Seasonal Testing Deferred to Next Cooling Season
A 200,000 ft² distribution center is completing construction in late October in a climate with design conditions of 95 °F dry bulb and 10% relative humidity in summer. The Cx provider's scope includes seasonal testing of the evaporative cooling units and the economizer sequence. The construction schedule requires substantial completion by November 15. The owner wants to occupy the building immediately and does not want to wait for summer to verify the evaporative cooling. The Cx provider notes that the evaporative coolers cannot be fully tested at outdoor conditions below 60 °F, and the economizer changeover cannot be verified without suitable outdoor air conditions. The contract documents are silent on seasonal testing timing and who bears the cost of a return visit.
1. How should the Cx provider handle the seasonal testing requirement given the schedule and the silent contract?
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The provider should not simply waive seasonal testing, nor should it block occupancy. The correct approach is to defer, document, and schedule:
- Identify what can and cannot be tested now. Evaporative cooling performance and economizer changeover require outdoor conditions that will not occur before November. These are legitimately deferred.
- Substitute where possible. Verify what can be verified at current conditions: controls logic in simulation or override, damper stroke and linkage, sensor calibration, freeze protection, and the sequence of operation via BAS forcing. Document which portions were verified and which were not.
- Issue a formal deferral list with the specific tests, the required conditions, and the proposed window (e.g., June–August of the following year).
- Address cost and responsibility in writing. Since the contract is silent, the provider should raise it to the owner and contractor now, before occupancy, and recommend a contract amendment or a holdback that covers the return visit. Silence now becomes a dispute later.
- Carry the deferred items into the final report as open items with a defined completion path, so the report is accurate and the owner knows the building is not fully commissioned.
2. The owner asks whether the building can be considered 'commissioned' at substantial completion. What should the provider say?
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The provider should be precise: the building can be substantially complete and occupiable, but it is not fully commissioned until the deferred seasonal tests are completed and any resulting deficiencies are corrected. The provider should:
- Distinguish substantial completion (construction and most systems ready for use) from commissioning completion (all functional and seasonal tests passed, training and systems manual delivered, final report issued).
- Recommend that the final commissioning report be issued in two parts, or issued with a clearly labeled 'open items' section listing the deferred seasonal tests and their status.
- Advise the owner of the risk of occupying with unverified evaporative cooling and economizer sequences - e.g., comfort or energy performance may not meet the OPR until verified.
- Recommend that the deferred testing be a condition of final acceptance or warranty closeout, with a named responsible party and a date.