Three different activities that get conflated
Many handovers slip not because of a technical failure but because three separate activities are treated as one. Each has a different output and a different responsible party:
| Activity | What it proves | Output |
|---|---|---|
| Balancing (TAB) | Every outlet and unit receives its design flow | An approved balancing report |
| Commissioning | Each system individually runs to its sequence of operation | Commissioning records |
| Integrated testing | The systems interact correctly during a real event | A witnessed integrated test record |
The order is not optional: an integrated test on an unbalanced system proves nothing, and balancing a system that has not been commissioned produces numbers that change after the first adjustment. Skipping a step means repeating all of them.
Who may perform the balancing
Accepted practice is that balancing is carried out by a NEBB-certified TAB firm (or AABC) in good standing — both bodies publish procedural standards for balancing. Owning instruments is not the qualification; a certified firm with a record is, and its certification document belongs in the submission package, not as a later attachment.
The step everyone skips: the deficiency report before balancing
Before balancing starts, the installed system must be examined and a deficiency report submitted listing anything that would prevent proper testing, adjusting and balancing.
Why this is the most important section here: balancing an incomplete system produces a report that looks finished but is not repeatable. A blocked filter, a missing damper, an unsealed AHU door, an outlet not yet installed — each gives readings that change the moment it is corrected. The team then arrives at inspection with a report that does not match reality, and everything is redone.
What the deficiency report should capture at minimum: installation completeness, duct sealing integrity, filter cleanliness, availability of test openings, electrical and controls readiness, and confirmed fan rotation direction.
What the balancing report must contain
- Complete documentation of the testing, adjusting and balancing work.
- Drawings indicating air outlets, thermostats and equipment — not tables of numbers alone; the reviewer must be able to tie each reading to its location.
- Design versus achieved readings for every outlet and unit.
- Instrument details and calibration dates.
The link that fails inspections: from balancing to the integrated test
In facilities with smoke control, balancing is not the goal but a precondition. The real approval sequence is:
- Balance the ventilation and smoke control systems.
- Test smoke control performance against the smoke control standard — pressure differences and door opening force.
- Integrated test proving the alarm drives dampers, fans, lifts and doors in the correct sequence.
- The cause and effect matrix is what that test is judged against: every cell must be demonstrated.
Fire and smoke dampers are the usual point of collapse: mechanically balanced, but their linkage to the BMS and the alarm logic never demonstrated. A damper that closes by hand but does not respond to an alarm signal passes balancing and fails the integrated test.
Common rejections and their engineering fix
| Rejection cause | Engineering fix |
|---|---|
| Balancing done by the contractor with no certified firm | Engage a certified firm in good standing and attach its certification to the package |
| No deficiency report before balancing | Examine the system, log the deficiencies and clear them before taking any reading |
| A report of numbers with no location drawings | Attach drawings showing every outlet, thermostat and item of equipment, numbered as in the tables |
| Instruments with no valid calibration certificate | Include instrument details and calibration dates in the report |
| Dampers balanced but not tied into the alarm logic | Demonstrate each damper responding to an alarm signal in the integrated test, not by hand |
| Integrated test attempted before balancing is complete | Follow the order: balance, commission, then integrated test |
| Cause and effect matrix not updated after site changes | Update the matrix before the test; the test judges the matrix itself |
What to take from your project specification, not from here
Deliberately absent: acceptable flow tolerances, the ventilation rates required per space type, and the list and sequence of tests the authority witnesses. The first is set by your project specification, the second by the ventilation standard adopted in the design, and the third by the competent authority. Assuming a "usual" tolerance is exactly what makes a report acceptable on one project and rejected on the next.