First-run inspection in Software

Drawer Denso QR Bar Code in Software First-run inspection

There is an assumption that the basic work of each trade is complete, that power is available to run equipment, and that devices can be

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After Design: Through Construction to Operation After Design: Through Construction to Operation 433

placed in operation without fear of damage All equipment is veri ed as ready to run with shipping stops and protective wrap removed, protective covers in place, surfaces cleaned of construction spatter, rotating parts able to move freely, etc Valves and dampers are placed in a normal position; uid-handling systems have been ushed clean and pressure-tested Insulation may or may not be nished, but work is at least in progress Control installations are complete and may have a rst-time setup With all components essentially there, the commissioning team goes from one device to the next, verifying basic function Motors are jogged to verify rotation; fans and pumps are run for enough time to see that things are all right, that power is available where needed, and that automatic valves and dampers will stroke The rst run does not require calibration or test of capacity or adjustment It merely con rms that the systems are intact, ready for tuneup and test by the specialist

Testing, adjusting, and balancing (TAB)

With all systems in place and all devices capable of operation, the TAB team takes over to prepare the work for nal delivery to the owner This team is best managed by the general contractor, who has ultimate responsibility for the quality of the project and who can assign the work of all subcontracts The work of the team then usually proceeds under the direction of an individual, or rm, independent of but working with the mechanical, sheet-metal, control, and electrical contractors, who can operate and adjust the systems without vested interest and with broader experience than any one of the specialized contractors might have Such a team leader is often referred to as a TAB contractor but the need is broader than just TAB What is needed is an operator who can place a system in operation and tune it up to optimal operating condition The system designer can be a help as well as a referee in the TAB work The designer knows the intent of the design and the anticipated interrelationship between components Some humility is required, however, for many designers have little actual operating experience and may not know how to manipulate and operate systems as well as do some of the old hands It is essential to have a member of the owner s eventual operating staff on hand for the start-up and TAB work Early familiarity with and knowledge of the system minimizes questions later on Some contractors, even designers, are reluctant to expose un nished work to the owner s staff because the loose ends of a major work are sometimes

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embarrassing, but the owner s people are often a great help with corrective ideas The work of the TAB team proceeds from one system to the next, covering air handling, uid handling, central plant, and controls There are established procedures for TAB work for nearly every type of system ASHRAE, the Associated Air Balance Council (AABC), the National Environmental Balancing Bureau (NEBB), and other agencies all have documentation for test and balance procedures Note that the objective is not just to make the systems perform as the drawings say, but now to actually do the job Design calculations are at best a prophetic estimate of what will be needed based on an owner s expressed intended use and an architect s designed structure Real life may vary somewhat from the anticipated The TAB team should be instructed and be willing to adjust to nal needs This does not mean willing to rebuild, unless defects are encountered, but to adjust within the capacity range of the systems One of the nal products of the TAB work is a report which documents the work accomplished The report usually includes reducedscale drawings that show the nomenclature and location of all points of test and adjustment and shows in tabular form the quantities sought (design performance), the initial condition encountered, and the nal condition attained, with analysis of any discrepancy and a report of corrective action Part of the report may re ect work with the control contractor in verifying the calibration and proper function of each control device within the system context At the conclusion of the TAB work, the designer and owner might ask the TAB team to reread selected measurements to verify the integrity of the work See Ref 2 for further discusison of this topic 143 Commissioning

Commissioning is an old idea, but, as a formal concept, is of fairly recent origin In the ASHRAE Handbook the term rst appears in the Applications, 1995 volume The activities it includes are those that have been found necessary beyond the actual construction process for achieving a complete and working HVAC system, which satis es the requirements of the design and the needs of the owner The term quality assurance is sometimes used The ideal, from owner s viewpoint, is that the commissioning team, selected by and working for the owner, will assist in the design phase as well as the construction phase, ensuring that the owner s needs are met by the design This is rarely the case except for those owners who have staff personnel with these capabilities And many owners do not

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