Carpark and tunnel ventilation testing in Sydney

Mechanical ventilation in carparks and vehicle tunnels has to work in more than one state. It runs continuously to clear vehicle emissions during normal operation, and it has to perform to a different duty when fire mode is activated. Carpark ventilation testing verifies that the exhaust and supply fans deliver the required airflow to each zone, and that the system does what it is supposed to do in every mode it is required to run in.

A fan that is running is not evidence that a system is compliant. Duct leakage, damper position, drive settings and system resistance all sit between the fan nameplate and the air actually moving through the space. The only way to know is to measure.

What the standard requires

Mechanical ventilation in buildings, including carpark supply and exhaust systems, is covered by AS 1668.2, which the National Construction Code calls up. ENGIC carries out ventilation system testing in general accordance with AS 1668.2 and the NCC, comparing measured airflow against both the design figures and the applicable requirements.

For fire-egress stairwells, the relevant standard is AS 1668.1 and the work is stairwell pressurisation testing, which is a separate scope.

What is tested

A complete carpark or tunnel ventilation test covers:

• Total fan airflow at system level. Measured by duct traverse using a pitot tube and micromanometer, which gives an accurate total for each fan rather than an inferred one.
• Individual grille airflow across all zones and levels. Each accessible grille or louvre is measured so distribution across the system is documented, not assumed.
• Fire mode performance. How the system behaves once fire mode is activated, including the fan duty achieved in that state.
• Normal ventilation mode performance. The everyday operating condition, tested and recorded separately.
• Noise measurement at specified locations, where this forms part of the scope. Measured with a calibrated sound level meter.

Each mode is recorded separately in the report. A system that satisfies its normal mode duty does not necessarily satisfy its fire mode duty, and a single set of readings cannot demonstrate both.

What testing typically reveals

Across carpark and tunnel systems, the findings tend to fall into a few recognisable categories:

• Uneven distribution between grilles. The system total can be close to design while individual zones sit well away from it, which is invisible without per-grille measurement.
• Fan duty differing between modes. A system correctly set for normal operation may not reach the duty required when fire mode is called.
• Damper position affecting zone distribution. Dampers set during construction, or moved since, redistribute air in ways the design never intended.
• Access limitations. Grilles that cannot be reached at the time of testing need to be recorded as untested rather than estimated.

None of these are exotic. They are the ordinary consequences of a large system being built, commissioned in stages and then modified, and they are exactly what a documented test exists to surface before handover or certification.

Where this work comes up

Carpark and tunnel ventilation testing is usually required:

• at commissioning and practical completion of a new installation
• after fan, drive, damper or control replacement
• where a certifier or consultant needs documented evidence to sign off
• when a system is suspected of underperforming, or is generating complaints
• as part of periodic compliance testing on an existing building

The clients requesting it are typically builders, fire services contractors and mechanical contractors who need the results as evidence rather than as a general assurance.

What ENGIC delivers

Every ventilation testing project produces a structured report delivered within 24 hours of site testing. It contains:

• a system summary with one line per fan, showing design against actual flow and the percentage of design achieved
• detailed per-grille airflow readings grouped by system
• results recorded separately for each operating mode tested
• pass or fail status against design airflow
• noise readings where noise measurement is in scope
• clear notes on defects, access limitations or installation issues found on site

The same instruments and reporting standard used on our commissioning work apply here, so the numbers stand up to consultant review.

We have carried out this work on multi-level carpark systems and vehicle tunnel exhaust systems in Sydney, testing in both fire mode and normal ventilation mode, with per-grille results documented across every zone and level tested.

Book carpark ventilation testing in Sydney

ENGIC provides carpark ventilation testing, vehicle tunnel exhaust testing and general ventilation system testing across Sydney and surrounding regions. One team, calibrated instruments, and a report in your hands within 24 hours of site testing.

If air balancing is needed on the same project, we do both in one visit, with one point of contact.

Contact ENGIC to discuss scope and timing for your project.