Airport Terminal HVAC Duct Guide — Passenger Terminal, Baggage Handling, Air Traffic Control, Border Force, Customs, Duty Free, ASHRAE 62.1 + AS 1668.2 + AS/NZS 60079 + NFPA 415

Why airport terminal HVAC duct is the most regulated piece of infrastructure ductwork in the country

An Australian airport terminal is the only piece of public infrastructure where seven independent regulatory chains intersect on the same ductwork drawing — the National Construction Code Class 9b assembly classification, the Aviation Transport Security Act 2004 secure-side envelope, the AQIS Biosecurity Act 2015 quarantine zoning, the AS/NZS 60079 hazardous area framework that wraps the apron face and the bulk fuel farm, the AS 1668.1 smoke spill system rated for the largest open volume in any public building in Australia, the FSANZ food safety code that governs the food court and the off-airport flight catering link, and the DDA AS 1428.1 accessibility framework that touches every diffuser, return grille and access panel within reach range of a passenger. Layered above the domestic regulatory stack sits the ICAO Annex 14 aerodrome, Annex 17 security and Annex 18 dangerous goods framework, with the CASA Civil Aviation Safety Authority CASR Part 139 aerodrome certification chain forming the technical airworthiness underpinning. Below the regulatory stack sits an operational reality: 50,000 to 100,000 passengers per day passing through Sydney Kingsford Smith YSSY or Melbourne Tullamarine YMML, peak-hour density spiking at 5,000 to 8,000 occupants per concourse zone within a single 60-minute departure or arrival window, an active Zone 1 jet fuel envelope sitting within metres of the terminal building face during every aircraft turnaround, an open volume concourse the size of a regional shopping centre where natural fire compartmentation is impossible, and an unbroken 24-hour operational tempo that intolerantly compounds any HVAC outage into a contractual penalty against the airline slot schedule.

This guide is the same engineering reference our SBKJ application team uses when an Australian airport operator scopes duct fabrication for a terminal expansion, a BHS baggage handling system upgrade, an ATC tower refurbishment, a Border Force SmartGate eGate rollout, an AQIS biosecurity area refit, a duty free fit-out, a flight catering bulk facility build or an ARFF station expansion. We have built the duct fabrication machinery on terminal-adjacent projects ranging from the regional general aviation aprons at Bankstown YSBK and Essendon YMEN through to the major international terminal expansions at the capital city hubs. The patterns repeat. The hazardous area envelope is unforgiving. The ICAO and CASR Part 139 chain compounds on top of the NCC and the local state building code stack.

Seven specific conditions make airport terminal HVAC duct harder than any other public infrastructure ventilation problem in Australia. First — the occupant load swings by an order of magnitude across the day. A regional airport like Hobart YMHB or Canberra YSCB runs from a near-empty overnight period through a peak-hour morning push that puts thousands of passengers through a check-in hall designed for steady-state ASHRAE 62.1 ventilation rates. The duct designer cannot oversize to peak alone because off-peak return-air balance, humidity control and energy NABERS rating all penalise oversized systems. Second — the apron face is a permanent active Zone 1 envelope. Every aircraft turnaround at the terminal gate involves jet fuel JP-8 or AVTUR Jet A-1 hydrant connection, fuel tank vent breathing, refueller tanker connection or AVGAS 100LL piston-aircraft service for general aviation. The Zone 1 envelope follows the aircraft and the fuel servicing equipment, and the terminal building face is permanently classified Zone 2 to a depth of 4.5 metres from any open hydrant or aircraft fuel system component. Third — the smoke spill volume is the largest in any public building. A wide-body international concourse at Sydney T1 or Melbourne T2 runs 100,000 cubic metres of single open-volume air space at clear-span heights of 18 to 25 metres, with no natural compartmentation. The smoke spill system must clear the volume to tenability within 6 minutes per the performance-based fire engineering brief and AS 1668.3 zoned smoke control, requiring smoke spill exhaust flow rates that exceed 200 to 400 cubic metres per second per zone. Fourth — the mission-critical envelope sits inside the public-facing envelope. The Airservices Australia AsA air traffic control tower, the Border Force SmartGate biometric processing room and the BHS Vanderlande control pulpit all run as ASHRAE TC 9.9 Class A1 mission-critical environments under the same roof as a 30 degree Celsius peak-day return air load from the public concourse. The internal acoustic, humidity and rate-of-change envelope is the tightest in any operational facility. Fifth — the security and biosecurity envelopes are physically and aerodynamically isolated. ASIC Aviation Security Identification Card controls airside access, the AQIS Biosecurity Act 2015 mandates HEPA-filtered exhaust from the quarantine inspection area, and the Customs-sealed duty free precinct runs under a separate bonded inventory regime with isolated extract. The HVAC duct designer must aerodynamically separate these envelopes from the public concourse return air path. Sixth — the exposure mix on the apron-facing terminal envelope is the worst in any commercial building. Jet fuel benzene at 1 ppm STEL (the killer), diesel exhaust at 0.1 mg/m cubed elemental carbon DPM, CO 30 ppm STEL, NO2 5 ppm STEL, PM2.5 10 mg/m cubed and AVGAS 100LL lead inorganic at 0.05 mg/m cubed all sit on the apron face directly upwind of the terminal supply intakes during prevailing wind. Seventh — the airline schedule is intolerant of HVAC downtime. A scheduled airline runs a heavy maintenance bay turnaround on a strict slot schedule against contracted aircraft availability targets, and any HVAC outage that grounds the gate beyond the contracted window triggers contractual penalties measured in tens of thousands of dollars per minute of delay across the airline network.

Sydney Melbourne Brisbane Perth airport passenger processing — the eight terminal process zones

A modern Australian airport terminal splits into eight sequential process zones from kerbside arrival through to aircraft boarding gate, each with its own ductwork specification. The duct designer cannot specify any zone in isolation because the building code, security envelope, biosecurity zoning, smoke spill system and apron Zone 1 hazardous area all chain through the entire facility.

Zone 1 — Kerbside, forecourt and ground transport interchange. The kerbside drop-off area, taxi rank, ride share zone, hotel shuttle bay, valet parking and short-stay carpark interchange. NCC Class 7a carpark classification with AS 1668.2 carpark ventilation at 6 ACH minimum and CO concentration capped at 25 ppm running 8-hour average per AS 1668.2 section 4. The covered drop-off area immediately adjacent to the terminal face is treated as a transition zone — partially enclosed, partially open — with jet fan ventilation extending 30 to 50 metres into the structure to clear the diesel exhaust plume from the bus, coach and taxi fleet circulating continuously through peak periods. Sydney Kingsford Smith T1 International forecourt, Melbourne Tullamarine T2 International drop-off, Brisbane International forecourt and Perth T1 kerbside all run jet fan ventilation arrays sized for the worst-case bus and coach idle scenario. Duct material is galvanised G90 spiral round at 1.2 to 1.6 mm gauge on the SBFB-1500 spiral former for the jet fan plenums and connection trunks.

Zone 2 — Check-in hall, kiosk and bag drop. The first internal occupied envelope after the kerbside transition. NCC Class 9b assembly with ASHRAE 62.1 ventilation at 12 L/s/person check-in hall, occupant density at peak hour 0.5 to 0.8 person per m squared and acoustic target NC-35 with NC-30 in the airline service desk back-of-house. The self-service kiosk and SmartGate eGate ePassport processing pod sit within the check-in hall as a separate climate zone with ESD-safe flooring and tighter NC-30 acoustic envelope to support the biometric processing rack. Sydney T1 check-in hall sees 5,000 to 8,000 peak-hour passenger throughput; Melbourne T2 sees 4,000 to 7,000; Brisbane International 3,000 to 5,000; Perth T1 2,500 to 4,000. The HVAC supply ductwork is galvanised at 0.8 to 1.2 mm on the SBAL-V galvanised configuration, sized for 600 to 1,800 mm rectangular trunk feeding overhead linear slot diffusers on a 4.5 to 6 metre grid. Return air paths include high-level return through the perimeter wall and ceiling void plenum return to the floor-by-floor AHU air handling unit.

Zone 3 — Security screening and outbound border processing. The aviation security checkpoint where AVSEC screening, X-ray cabin baggage scan, walk-through metal detector WTMD and trace explosive detection ETD operate under the Aviation Transport Security Regulations 2005 framework. Adjacent to security sits the outbound Border Force Australian Border Force ABF SmartGate eGate ePassport processing pod for departing international passengers. The security screening envelope runs at ASHRAE 62.1 12 L/s/person ventilation with NC-30 acoustic target and a separate ESD-safe climate zone for the X-ray cabinet and biometric processor. The biometric processing room is a sub-zone at ASHRAE TC 9.9 Class A1 with 22 to 27 degrees Celsius and 8 to 90% RH envelope, fed by a dedicated CRAH chilled-water computer room air handler and ducted in 304L stainless at 1.0 mm to prevent any ferrous duct corrosion contaminating the optical biometric scanner. The Department of Home Affairs and AFP Australian Federal Police observation deck and command room sit on a separate secure-side climate zone with restricted ductwork access and tamper-evident penetrations.

Zone 4 — International transit and duty free retail concourse. The transit and duty free precinct between security clearance and the gate lounge. NCC Class 6 retail classification with separate climate zone, ASHRAE 62.1 ventilation at 7.5 L/s/person retail, acoustic NC-35 ambient music level, separate tax zone with Customs seal at the entry threshold, duty-free locker storage for pre-flight collection and Customs declaration desk for over-allowance inspection. Duty free is operated under concession by Dufry, Heinemann, JR Duty Free or The Fragrance Company at Sydney T1, Melbourne T2, Brisbane International, Perth T1, Adelaide YPAD and Cairns YBCS. The fragrance and cosmetic sales floor generates a heavy VOC mix at 100 to 500 ppmv total VOC from perfume tester bottles, alcohol-based cosmetic and aerosol packaging — formaldehyde 1 ppm STEL from preservative and laminate fit-out, ethanol from perfume base at 1,000 ppm WES, fragrance VOC alpha-pinene, limonene and linalool at general VOC limit. The duty free extract is sized at 12 to 15 L/s/m squared with 316L stainless 1.5 mm exhaust ductwork on the SBAL-V back through a dedicated activated carbon adsorber before discharge to the airside roof stack. Adjacent retail concessions include Heinemann Tax & Duty Free, Hudson News, WHSmith, JR Tobacco, perfumery brand stores (Chanel, Estee Lauder, Dior, MAC), confectionery and Australian craft retail. The food court and cafe precinct adjacent to the duty free runs under NCC Class 6 with FSANZ HACCP 4.2.1, 4.2.2 and 4.2.3 compliance, separate kitchen extract under NFPA 96 with make-up air balance.

Zone 5 — Gate lounge and pier finger. The boarding gate hold-room and pier finger walkway that connects the concourse to the aerobridge. NCC Class 9b assembly with ASHRAE 62.1 ventilation at 12 L/s/person gate lounge, acoustic NC-35 with NC-30 in any boarding agent service area, and an active Zone 2 hazardous area envelope to a depth of 4.5 metres from the aerobridge face during fuelling. The gate lounge fixed seating capacity at Sydney T1 International is 200 to 400 per gate, at Melbourne T2 international 150 to 350, at Brisbane International 200 to 400 and at Perth T1 150 to 300. Peak occupancy during boarding spikes to 1.5 to 2 times the seated capacity as standing passengers cluster at the boarding gate. The HVAC supply ductwork is galvanised at 0.8 to 1.2 mm on the SBAL-V, with the apron-facing wall fitted with hydrocarbon vapour detection that interlocks to shut the supply intake on any detected JP-8 vapour exceeding 25% LEL. The aerobridge climate zone is a separate envelope with portable AHU connection to the aircraft cabin during boarding and disembarkation — the aerobridge AHU is sized for 2 to 5 cubic metres per second to provide cabin air during ground hold without engine APU operation.

Zone 6 — Aerobridge, airside ramp and apron face. The transition envelope between the terminal building and the aircraft. NCC Class 9b assembly inside the aerobridge and AS/NZS 60079 Zone 1 within 1.5 metres of the aircraft and Zone 2 within 4.5 metres of any open fuel system component on the apron. The aerobridge floor-level air conditioning unit supplies conditioned air to the aircraft cabin during ground hold, with the duct connection from the aerobridge AHU to the aircraft cabin door rated for 2 to 5 cubic metres per second and 12 to 25 degrees Celsius supply air. The apron-side ramp area beyond the aerobridge handles ground support equipment GSE including baggage tug, container loader, catering truck, pushback tractor, air-start unit, ground power unit GPU 400 Hz, and oxygen cart. GSE diesel exhaust and AVGAS 100LL pushback gives a CO concentration at the apron face of 5 to 50 ppm, NO2 at 0.5 to 5 ppm, particulate PM2.5 at 10 to 50 microgram per m cubed and benzene aromatic fraction from atomised jet fuel mist. The terminal building face supply intake must be set back from the apron face by 15 metres minimum per NFPA 415, or located on the landward face to draw cleaner air from the carpark and ground transport side.

Zone 7 — Arrival hall, baggage carousel and Border Force AQIS biosecurity. The inbound passenger processing envelope from aircraft disembarkation through to public concourse exit. NCC Class 9b assembly with ASHRAE 62.1 ventilation at 12 L/s/person arrival hall, acoustic NC-45 in the baggage carousel hall and NC-35 in the public arrivals concourse. The inbound Border Force SmartGate eGate ePassport processing pod sits between aerobridge and baggage carousel, with the AQIS Biosecurity Act 2015 quarantine inspection area and X-ray secondary scan and dog sniffer envelope downstream. The quarantine inspection area runs as a negative-pressure zone at minus 5 to minus 15 Pa relative to the public arrivals corridor, with HEPA H13 to H14 filtered exhaust to prevent any biosecurity hazard release. Duct material in the quarantine zone is 316L stainless at 1.2 mm because chemical decontamination spray with quaternary ammonium or peracetic acid may be applied at end-of-shift. The baggage carousel hall runs the high-volume conveyor and tilt-tray sorter under acoustic NC-45 with general ventilation at 0.3 to 0.5 L/s/m squared and local capture at 1.5 to 2.5 L/s/m squared at the X-ray tunnel and tunnel discharge.

Zone 8 — Back-of-house, plant room and operational support. The non-public envelope including HVAC plant room, electrical switchroom, BHS control pulpit, airline crew room, ATC tower base, ground handling office, AFP Department of Home Affairs office, ASIC card issue office, ground service vehicle ramp, fuel hydrant pit cluster, ARFF aircraft rescue fire fighting station and the airport authority management suite. Acoustic target ranges from NC-25 in the ATC controller cab and any prayer room, NC-30 in the airline crew lounge and SmartGate biometric processing room, NC-35 in the public concourse, NC-45 in the baggage hall and NC-55 in the plant room. The HVAC plant room itself runs at NC-55 and the duct connection from the AHU to the supply riser is on the SBAL-V galvanised at 1.0 to 1.2 mm with TDF flanges and acoustic lining at the AHU discharge.

ASHRAE 62.1 passenger ventilation rates — the Australian terminal occupancy load

ASHRAE 62.1 is the global reference for ventilation rate procedure in commercial buildings, and AS 1668.2 mirrors most of the rate values for Australian application. The airport terminal designer cross-references both because the building code Class 9b assembly classification triggers AS 1668.2 directly, but the international airline tenant fit-out specifications and the major design consultancies all default to ASHRAE 62.1 as the technical baseline.

The ASHRAE 62.1 ventilation rate procedure splits the calculation into people-related (Rp) and area-related (Ra) components. For an airport concourse the people-related rate is 7.5 L/s/person and the area-related rate is 0.3 L/s/m squared, summing to a typical concourse ventilation requirement of 15 L/s/person at the 0.5 to 0.8 person per m squared peak hour density. The gate lounge ventilation rate is similar at 12 L/s/person. The check-in hall sits at 12 L/s/person because of slightly lower occupant density and shorter dwell time. Retail and duty free runs at 7.5 L/s/person, food court at 7.5 L/s/person plus the kitchen exhaust make-up. The prayer room runs at 5 L/s/person but with a quiet acoustic target at NC-25 that the ductwork designer must achieve through duct lining and low-velocity supply.

For the Sydney Kingsford Smith T1 International concourse running 44 million passengers per year prior to 2020 (the absolute peak in Australian aviation), the peak hour passenger throughput is 5,000 to 8,000 occupants in a 60-minute window. At the 15 L/s/person concourse rate and 80% diversity factor across the concurrent occupied zones, the outside air ventilation rate is 60 to 96 cubic metres per second of outside air, with total supply air rate including cooling load make-up of 200 to 350 cubic metres per second across the concourse zone. The same calculation at Melbourne Tullamarine T2 International (37 million passengers 2019, the second-largest in Australia) sizes the concourse outside air to 50 to 80 cubic metres per second. At Brisbane Airport YBBN (24 million passengers, BAC Brisbane Airport Corporation) the concourse outside air is 32 to 50 cubic metres per second. At Perth Airport YPPH (14 million passengers, Perth Airport Pty Ltd) the concourse outside air is 19 to 30 cubic metres per second. At Adelaide YPAD (5.6 million passengers, terminal 1995 expansion) the concourse outside air is 8 to 12 cubic metres per second. At Cairns YBCS (Cairns Airport Pty Ltd, North Queensland Airports NQA) the concourse outside air is 6 to 10 cubic metres per second. At Darwin YPDN (Northern Territory Airports, joint-use defence with RAAF Tindal cross-over) the concourse outside air is 4 to 8 cubic metres per second. At Hobart YMHB (Hobart Airport Pty Ltd, Macquarie Group) the concourse outside air is 4 to 8 cubic metres per second. At Canberra YSCB (Capital Airport Group, defence cross-over with RAAF and Air Canberra) the concourse outside air is 5 to 10 cubic metres per second. At Avalon YMAV (Linfox-owned, Geelong VIC, Jetstar and AirAsia LCC base) the concourse outside air is 4 to 8 cubic metres per second.

The general aviation network at Bankstown YSBK, Camden, Essendon YMEN, Moorabbin YMMB and Archerfield YBAF runs smaller terminal envelopes serving training school, flying club, helicopter base and corporate jet operations. The terminal at Bankstown YSBK or Essendon YMEN is typically 500 to 2,500 m squared NCC Class 9b assembly with ASHRAE 62.1 12 L/s/person and an acoustic target NC-35. The corporate jet FBO Fixed Base Operator lounge at the major capital airports (Hawker Pacific, Avwest, Australian Jet Charter) runs at NC-30 with elevated ventilation rate at 15 L/s/person and Wi-Fi-grade acoustic privacy.

Beyond the headline concourse and gate lounge rates, the duct designer must handle a portfolio of occupancy classes within the same terminal envelope. The retail food court at 7.5 L/s/person plus the NFPA 96 commercial kitchen exhaust at 0.4 to 0.5 m/s capture velocity. The cafe and bar precinct at 7.5 L/s/person with separate kitchen extract. The VIP lounge (Qantas Chairman's Lounge, Qantas International First, Qantas Business, Virgin Velocity, Star Alliance, Oneworld and SkyTeam partner lounges) at 12 to 15 L/s/person with elevated acoustic at NC-25 and luxury catering with separate kitchen extract. The medical clinic and first aid at NCC Class 9a healthcare with ASHRAE 170 medical ventilation, vaccine fridge 2 to 8 degrees Celsius, AS/NZS 4187 sterile reprocessing and post-COVID pandemic surveillance HVAC. The childcare and family room at NC-30 with separate climate zone. The multifaith prayer chapel at NC-25 quiet with ablution facility wudu for Muslim prayer and separate ventilation for Catholic Mass, Anglican, Greek Orthodox, Hindu, Buddhist, Sikh and Jewish observance.

AS 1668.3 zoned smoke control for the very large open-volume concourse

The Australian terminal concourse is one of the few environments in commercial building practice where natural fire compartmentation is physically impossible. A single international concourse at Sydney T1 or Melbourne T2 runs 100,000 cubic metres of single open-volume air space at clear-span heights of 18 to 25 metres, with retail and gate lounge precincts opening freely onto the central concourse. The fire engineer cannot wall off the concourse into smaller compartments because the architectural intent and the passenger wayfinding both demand the open volume. The smoke control system must therefore work in the open volume rather than within compartments.

AS 1668.3 governs zoned smoke control for these large open-volume environments. The standard splits the concourse into smoke control zones — typically 4 to 8 zones per concourse — with each zone served by its own smoke spill exhaust fan and supply make-up air path. On fire alarm activation in any zone, the smoke spill exhaust fan in that zone operates at full design flow while the supply make-up fan in adjacent zones provides positive pressure to prevent smoke spread. The performance-based fire engineering brief sets the target tenability time (typically 6 minutes from alarm to tenability achievement) and the smoke spill flow rate is back-calculated from the smoke production rate of the worst-case design fire (typically 2 to 5 MW heat release rate from a retail or food court fire load).

The ductwork implications of AS 1668.3 zoned smoke control are significant. First, the smoke spill ductwork from each zone is sized for 50 to 100 cubic metres per second peak flow rate, requiring large-section galvanised duct at 1.6 to 2.0 mm gauge with continuous welded seams. The SBAL-V galvanised configuration handles the rectangular sections up to 2,000 mm wide, and the SBAL-III handles the wider 2,000 to 2,500 mm sections used in the largest concourse zones. The SBSF-1525 stitchwelder produces the continuous longitudinal seam weld and the manual MIG/MAG finish pass that holds the 250 degree Celsius / 2 hour fire rating per AS 1668.1 and AS 1530.4. Second, the smoke spill riser shaft from the concourse roof level down through the building to the smoke spill fan room is fabricated in heavy-gauge galvanised with bolted flange joints at every 3 metre lift, sized for the peak smoke spill flow. Third, the make-up air supply ducts feeding the adjacent zones during smoke spill operation must equal the exhaust flow within plus or minus 10% to prevent the concourse going negative pressure and pulling smoke from adjacent compartments. Fourth, motorised dampers at every smoke zone boundary must be rated F300/120 (operating at 300 degrees Celsius for 120 minutes) and certified to AS 1668.1 section 7. Fifth, the smoke spill exhaust fan itself is rated F300/120 and located on the roof of the concourse or in a dedicated smoke spill fan room with direct discharge to atmosphere.

The check-in hall at Sydney T1 International, Melbourne T2 International and Brisbane International is similarly treated under AS 1668.3 because the open volume above the check-in counters and the airline service desks exceeds the maximum compartment size for natural compartmentation. The check-in hall smoke spill is sized for 100 to 200 cubic metres per second peak flow per zone, with 4 to 6 zones per check-in hall depending on the building geometry.

Jet fuel apron Zone 1 AS/NZS 60079 — the terminal-to-apron envelope

AS/NZS 60079.10.1 is the Australian implementation of the IEC 60079 hazardous area framework and the dominant reference for any apron-adjacent ductwork design. The standard defines three zones based on the likelihood of an explosive atmosphere being present. Zone 0 covers continuous explosive atmosphere — the interior of an aircraft fuel tank during fuel-tank-entry maintenance qualifies, and the vapour space inside any bulk fuel storage tank at the airport fuel farm. Zone 1 covers explosive atmosphere likely to occur in normal operation — within 1.5 metres of an aircraft fuel dispenser nozzle, the hydrant pit, the refueller tanker dome and any open fuel tank vent; within 3 metres of a fuel farm tank vent; and inside the AS 1940 flammable liquid store. Zone 2 covers explosive atmosphere unlikely to occur but possible — within 4.5 metres of any aircraft fuel system component, within 7.5 metres of a fuel farm tank vent, in the AVGAS 100LL piston-aircraft service area at the GA general aviation airports including Pearce WA, Edinburgh SA, Avalon, Bankstown, Essendon, Moorabbin and Archerfield, and in the lithium-ion battery storage room (because Li-ion off-gas including hydrogen fluoride HF at 1.8 ppm STEL and other electrolyte vapours can occur on thermal runaway).

The hazardous area classification drawing is the most important single document the airport HVAC duct designer needs before specifying any equipment. Every electrical penetration through the duct — fire damper actuator, smoke spill fan motor, supply air handler fan motor, control damper actuator, instrumentation transmitter, hydrocarbon vapour detector head — must be selected to the zone classification at the penetration point. Inside Zone 1 the electrical equipment must be Ex-d flameproof, Ex-e increased safety or Ex-i intrinsically safe to AS/NZS 60079.14, and the equipment certification must include compatible gas group (IIA for aviation kerosene JP-8 and AVTUR Jet A-1, IIB for ethylene-containing solvent if any duty free aerosol release, IIC for hydrogen H2 if the airport hosts an emerging hydrogen refuelling station for fuel cell ground support equipment). Inside Zone 2 the equipment can be Ex-n non-incendive (a less stringent classification) but must still hold a current certificate.

The terminal-to-apron envelope creates three specific hazardous area design challenges for the HVAC duct designer. First — the supply air intake location. NFPA 415 mandates a 15 metre minimum setback of any unprotected intake from the fuel servicing zone, and AS/NZS 60079.10.1 requires the intake to be located outside the Zone 2 envelope. The practical solution is to locate the supply intake on the landward face of the terminal building, drawing air from the carpark and ground transport side rather than the apron face. At Sydney T1 International, Melbourne T2 International, Brisbane International and Perth T1 the supply intakes are exclusively on the landward face, with no airside intake permitted within the AS/NZS 60079.10.1 Zone 2 envelope. Second — the apron-facing wall hydrocarbon vapour detection. Any terminal building face within 4.5 metres of the apron must be fitted with continuous hydrocarbon vapour detection (typically infrared open-path or point-source IR detectors calibrated for JP-8 kerosene) that interlocks to shut the supply intake damper on any detected vapour exceeding 25% LEL. Third — the aerobridge duct connection to the aircraft cabin. The aerobridge floor-level AHU supplies conditioned air to the aircraft cabin during ground hold, and the duct connection from the aerobridge to the aircraft door sits permanently within the AS/NZS 60079.10.1 Zone 2 envelope. The aerobridge AHU fan motor must be Ex-n non-incendive Zone 2 certified, the duct connection material is 316L stainless at 1.2 mm with conductive bonding to the aircraft frame through a low-resistance bonding cable, and the supply air diffuser at the cabin door must be all-metal construction without any plastic or composite component that could accumulate static charge.

The fuel farm bulk storage and the airport hydrant pipeline classification adds a further hazardous area envelope. Sydney Caltex Mascot, Melbourne Tullamarine Viva Energy, Brisbane BP, Perth Q-Service and the joint fuel terminal arrangement at each capital city airport operate bulk JP-8 and AVTUR Jet A-1 storage in 1,000 to 5,000 cubic metre vertical cylindrical tanks. Each tank vapour space classifies as Zone 0 (continuous explosive atmosphere) with a Zone 1 envelope extending 3 metres from any tank vent and a Zone 2 envelope extending 7.5 metres. The hydrant pipeline runs underground from the fuel farm to each apron hydrant pit, and the pit interior classifies as Zone 1 with a Zone 2 envelope extending 4.5 metres above ground. The vapour recovery system at the fuel farm stage I (tanker offloading to bulk tank) and the stage II point of sale (refueller tanker to aircraft) returns the displaced fuel vapour to the bulk tank rather than venting to atmosphere, and the recovery duct is 316L stainless at 2 to 3 mm gauge on the SBSF-1525 stitchwelder with continuous welded seam and ESD-safe conductive bonding throughout. The hydrant pipeline external service envelope where it crosses any roadway, taxiway or vehicle traffic zone is 309S or 310S heavy-gauge stainless at 3 to 6 mm wall thickness, cut on the SBPC1500 plasma table and welded manually with stainless filler matching the parent material.

BHS baggage handling system Vanderlande BEUMER — high-volume conveyor and EDS X-ray ductwork

The baggage handling system at every major Australian international airport is supplied by one of the global BHS specialists — Vanderlande, BEUMER, Glidepath (a New Zealand-headquartered specialist with strong Australian market presence), Crisplant or Daifuku. A typical international BHS at Sydney T1, Melbourne T2, Brisbane International or Perth T1 runs 5,000 to 12,000 bags per hour peak throughput with tilt-tray sorter, overhead cross-belt sorter and inline EDS Explosive Detection System screening from L3Harris (NRC formerly), Smiths Detection or Rapiscan ESD. The baggage hall classifies as NCC Class 7b storage in the bag holding and sorting area, with NCC Class 9b assembly in the public-facing baggage claim carousel hall.

The ductwork specification for the BHS combines several distinct ventilation challenges. First — general ventilation of the baggage hall at 0.3 to 0.5 L/s/m squared per AS 1668.2 for the large enclosed volume holding the conveyor network and the operator pulpit. Acoustic target is NC-45 in the baggage hall because conveyor belt noise, motor noise and the high-frequency tilt-tray sorter impact noise dominate the ambient sound level. Second — local capture at 1.5 to 2.5 L/s/m squared at the X-ray EDS tunnel exhaust where ozone, X-ray ozone byproducts (typically 0.05 to 0.2 ppm in the tunnel exhaust), conveyor belt wear particulate and trace explosive residue from the secondary inspection swab can accumulate. Third — ESD-safe ductwork throughout the BHS envelope because conveyor belt friction generates static charge that can transfer to the duct envelope and any non-bonded metal component, creating an ignition risk for the lithium-ion battery cargo that increasingly arrives in checked baggage. Fourth — smoke control of the baggage hall under AS 1668.1 and AS 1668.3 because the open volume of the bag holding area is large enough to require zoned smoke control treatment.

Duct material for the BHS general ventilation is galvanised G90 (Z275) at 1.0 to 1.2 mm gauge with TDF rectangular trunk fabricated on the SBAL-V galvanised configuration and spiral round branch fabricated on the SBFB-1500 spiral former. The ESD-safe earthing terminals are mandatory at every 6 metres of conveyor-adjacent duct, with a continuous copper braid bonding strap from the duct envelope to the building structural steel at every 6 metres. The local capture ductwork at the X-ray EDS tunnel exhaust is 316L stainless at 1.2 to 1.5 mm because the trace explosive residue and the ozone byproduct create a mild corrosive environment on galvanised coating. The activated carbon adsorber that treats the local capture exhaust before discharge to atmosphere is sized for 12 to 15 L/s/m squared face velocity and 0.5 to 1.0 second residence time at typical loading.

The BHS operator pulpit and control room is a separate sub-zone running at ASHRAE TC 9.9 Class A1 IT cabinet thermal management for the BHS PLC programmable logic controller, the EDS image review workstation and the network switchgear that connects to the airport central operations centre. Acoustic target inside the pulpit is NC-30 (one step tighter than the surrounding baggage hall) to support the operator decision-making on the EDS image review. Duct material in the pulpit is galvanised at 0.8 to 1.0 mm on the SBAL-V with TDF flanges and acoustic lining at the supply diffuser.

The baggage claim carousel hall in the public-facing arrivals envelope is treated separately because it sits within the NCC Class 9b assembly classification and operates at higher occupant density. ASHRAE 62.1 ventilation at 12 L/s/person, acoustic target NC-45 (the same as the back-of-house baggage hall because of the carousel mechanism noise), and additional local capture at the AQIS Biosecurity X-ray secondary inspection station and the dog sniffer station. The post-COVID surveillance HVAC retained at most Australian international ports includes a thermal camera FLIR fever screening station and a portable mass spectrometer or FTIR for trace pathogen screening — the operating envelope around these instruments runs at ASHRAE TC 9.9 conditions with a separate ducted feed.

Duty free retail tax-free Dufry Heinemann JR — perfume VOC and Customs-bonded inventory

The duty free retail precinct is the highest-value commercial real estate in any international airport terminal. Sydney T1 International duty free is operated under concession by Heinemann (Lagardere Travel Retail), Melbourne T2 International duty free by Heinemann, Brisbane International duty free by Heinemann, and Perth T1 duty free by Dufry. Adjacent retail concessions include JR Tobacco, Hudson News, WHSmith, The Fragrance Company, perfumery brand stores (Chanel, Estee Lauder, Dior, MAC), confectionery and Australian craft retail. The duty free precinct at Adelaide YPAD and Cairns YBCS is smaller scale with single concessionaire operation.

The duty free shop classifies as NCC Class 6 retail with separate climate zone, ASHRAE 62.1 ventilation at 7.5 L/s/person retail, acoustic NC-35 ambient music level, separate tax zone with Customs seal at the entry threshold, duty-free locker storage for pre-flight collection and Customs declaration desk for over-allowance inspection. The Customs-sealed bonded inventory regime requires that the duty free precinct is physically and aerodynamically separated from the public concourse return air path so that any unauthorised product transfer between zones can be detected. The HVAC duct designer treats the duty free as a separate climate zone with its own AHU and dedicated supply and return ductwork, with no return air sharing across the Customs seal boundary.

The fragrance and cosmetic sales floor generates the most complex VOC and exposure profile of any retail environment in commercial building practice. Open perfume tester bottles release a continuous fragrance VOC mix at 100 to 500 ppmv total VOC concentration, dominated by ethanol (perfume base, typically 70 to 90% v/v) at 1,000 ppm WES, fragrance terpenes (alpha-pinene, limonene, linalool, geraniol) at the general VOC limit, alcohol-based cosmetic and aerosol propellant. Formaldehyde at 1 ppm STEL appears from preservative chemistry in cosmetic product, from MDF and laminate fit-out, and from the duty free perfume packaging. The combination of high ethanol concentration and small enclosed volume creates an emerging fire risk — perfume tester area fires have been recorded at international airports overseas where ignition of evaporated ethanol from open testers initiated a flash fire. The duty free precinct fire engineering brief typically includes localised gas detection for ethanol vapour and a positive-pressure ventilation regime to ensure that any ethanol accumulation is swept out of the sales floor envelope.

The duty free extract is sized at 12 to 15 L/s/m squared in the fragrance and cosmetic sales area (significantly higher than the 7.5 L/s/person ASHRAE 62.1 baseline) with 316L stainless 1.5 mm exhaust ductwork on the SBAL-V back through a dedicated activated carbon adsorber before discharge to the airside roof stack. The activated carbon adsorber is sized for 0.3 to 0.5 m/s face velocity and 1 to 2 second residence time at typical loading, with carbon replacement every 6 to 12 months depending on perfume release intensity. The general retail and confectionery area runs at the lower ASHRAE 62.1 7.5 L/s/person baseline with galvanised duct on the SBAL-V at 0.8 to 1.0 mm.

The duty free liquor and tobacco precinct operates under additional Customs surveillance because the duty saving on these product categories is among the highest in the duty free retail mix. The liquor store fixed shelving and display refrigeration runs on R32 or R454B HFC-blend refrigerant for chilled wine and champagne display, ducted to a low-acoustic supply and return path to avoid disturbing the customer experience. The tobacco precinct — declining year on year as smoking rates fall and tobacco retail moves online — runs at a separate ventilation rate to manage residual tobacco product odour during stock handling.

Air traffic control ATC Airservices Australia AsA — mission-critical ASHRAE TC 9.9 envelope

The air traffic control tower at every Australian airport runs under the Airservices Australia AsA operational authority as a mission-critical communication and radar facility. The Sydney, Melbourne, Brisbane and Perth ATC towers are continuously staffed with 4 to 8 controllers per shift covering the terminal control area, approach control, departure control and ground movement control. Adelaide, Cairns, Darwin and Canberra ATC towers operate with 2 to 4 controllers per shift. The regional GA tower network at Avalon YMAV, Bankstown YSBK, Essendon YMEN, Moorabbin YMMB and Archerfield YBAF operates as a Class D control tower with 1 to 2 controllers per shift covering the immediate aerodrome control zone.

The ATC tower internal environment runs under ASHRAE TC 9.9 Class A1 mission-critical — 22 to 27 degrees Celsius dry bulb with 8 to 90% relative humidity envelope and a 9 degree Celsius per hour maximum rate of temperature change. The tight humidity ramp control prevents condensation on the electronic equipment surfaces during a rapid outdoor weather transition. The Mode S secondary surveillance radar SSR, ADS-B Automatic Dependent Surveillance Broadcast receiver, VOR VHF omnidirectional range, DME distance measuring equipment, ILS instrument landing system, ATIS automatic terminal information service, voice communication switch and the controller working position consoles all sit on a redundant N+1 cooling architecture with chilled-water computer room air handlers CRAHs feeding overhead supply ductwork.

Duct material in the ATC tower is 304L stainless at 1.0 mm gauge with TDF flanges fabricated on the SBAL-V stainless configuration. The choice of 304L over galvanised reflects the long service life expected of a mission-critical facility (typically 30 to 40 year duct life expectancy) and the need to avoid any ferrous corrosion that could affect the radar and communications equipment in the same room. The supply ductwork runs as a four-pipe chilled water and hot water reheating system with constant-air-volume terminal boxes at each controller working position to enable individual temperature adjustment per controller.

Acoustic target inside the controller cab is NC-25 — the tightest acoustic specification in any operational facility — because the controller listens to multiple voice channels simultaneously through headset and any duct-borne noise above NC-25 degrades the safety of separation in approach and en-route control. The ductwork designer achieves NC-25 through several measures — low-velocity supply at 2 to 3 m/s in the duct trunk and 1.5 to 2 m/s at the diffuser, acoustic lining of the supply and return duct (typically 50 mm mineral wool with perforated stainless inner sheet to avoid fibre release into the controller breathing zone), spring isolation of the supply AHU and return fan, and flexible connection at every AHU discharge to break the duct-borne vibration path.

The radar room and the equipment room at the base of the ATC tower run at ASHRAE TC 9.9 Class A1 with tight humidity control and N+1 redundancy. The supply ductwork in the equipment room is sized for the heat dissipation load of the rack-mounted radar processor, voice communication switch and the network gateway to the airport central operations centre. Typical heat load is 5 to 15 kW per rack with 4 to 12 racks per equipment room, sizing the supply air at 1 to 5 cubic metres per second per equipment room.

The approach radar facility at the major capital city airports (Sydney, Melbourne, Brisbane, Perth) is a separate facility from the ATC tower, located several kilometres from the runway to provide an unobstructed radar horizon. The approach radar facility runs the same ASHRAE TC 9.9 Class A1 environment with N+1 redundant chilled water and dedicated standby diesel generator. The duct material and gauge are identical to the ATC tower specification.

Border Force AQIS SmartGate eGate biometric — secure side envelope

The Australian Border Force ABF and the Department of Home Affairs Aviation Transport Security regime under the Aviation Transport Security Act 2004 and the Aviation Transport Security Regulations 2005 mandates secured airside access controlled by ASIC Aviation Security Identification Card. The SmartGate and eGate ePassport processing pods at Sydney T1, Melbourne T2, Brisbane International, Perth T1, Adelaide, Cairns, Darwin, Hobart and Canberra International handle the inbound and outbound border processing for Australian and New Zealand passport holders eligible for self-service biometric clearance, plus the expanded e-Visitor eligible passport list under the SmartGate enrolment regime.

The SmartGate eGate runs as a separate climate zone with ESD-safe flooring, ASHRAE TC 9.9 IT cabinet thermal management for the biometric processing rack, photocell illumination at 500 to 750 lux for the facial recognition camera, FLIR thermal camera fever screening (legacy post-COVID surveillance retained at most ports) and a quiet acoustic envelope at NC-30 to support the retina scan and facial recognition algorithm. The biometric processing rack itself sits inside a temperature-controlled cabinet at 22 to 25 degrees Celsius with 40 to 60% RH humidity, fed by a dedicated split-system or chilled-water riser branch off the main terminal HVAC ductwork.

The Department of Home Affairs and AFP Australian Federal Police observation deck and command room sit on a separate secure-side climate zone with restricted ductwork access and tamper-evident penetrations. ASIO Australian Security Intelligence Organisation surveillance footprint at the major international ports is a further restricted zone with no public-facing ductwork penetration. The AS 4587 anti-vandal envelope around the SmartGate and the Border Force office is a structural requirement that the HVAC duct designer must accommodate through tamper-evident grilles and tamper-evident access panels on all ductwork accessible from the public side.

The AQIS Biosecurity Act 2015 quarantine inspection area for X-ray secondary scan and dog sniffer is a separate negative-pressure envelope at minus 5 to minus 15 Pa relative to the public arrivals corridor, with HEPA H13 to H14 filtered exhaust to prevent any biosecurity hazard release into the public terminal. The inspection benches handle live animal product, plant material, soil samples and undeclared food items, and the operator-breathing-zone exposure to biosecurity hazards is managed through both negative pressure containment and operator PPE. Duct material in the AQIS quarantine zone is 316L stainless at 1.2 mm because chemical decontamination spray with quaternary ammonium QAC, peracetic acid or chlorine dioxide ClO2 may be applied at end-of-shift after a positive biosecurity detection.

The AQIS dog sniffer kennel and handler office is a sub-zone within the quarantine envelope with separate ventilation to manage the dog dander, hair and waste odour. ASHRAE 62.1 ventilation rate at 12 L/s/person plus 0.6 L/s/m squared for the kennel area, acoustic NC-35 in the handler office and NC-45 in the kennel itself.

The post-COVID surveillance HVAC retained at most Australian international ports includes a thermal camera FLIR fever screening station and a portable mass spectrometer or FTIR Fourier transform infrared for trace pathogen and biosecurity screening. The operating envelope around these instruments runs at ASHRAE TC 9.9 conditions with a separate ducted feed from the main terminal HVAC, and the duct material is 304L stainless at 1.0 mm to avoid any ferrous corrosion affecting the instrument calibration.

ARFF aircraft rescue fire fighting Cat X PFAS AFFF F3 foam — the foam phase-out transition

The ARFF aircraft rescue fire fighting station at every Australian Category IV through Category X airport houses the crash tender vehicle fleet and the foam concentrate store. Sydney YSSY is Cat IX or X, Melbourne YMML is Cat IX, Brisbane YBBN is Cat IX, Perth YPPH is Cat VIII or IX, Adelaide YPAD is Cat VII or VIII, Cairns YBCS is Cat VII, Darwin YPDN is Cat VII (with defence cross-over to RAAF Tindal), Hobart YMHB is Cat VI, Canberra YSCB is Cat VI or VII (with defence cross-over to RAAF Fairbairn), Avalon YMAV is Cat V or VI, and the regional GA airports at Bankstown, Camden, Essendon, Moorabbin and Archerfield operate without full ARFF coverage relying on the surrounding state fire and emergency service.

The ARFF crash tender fleet includes Rosenbauer Buffalo, Striker, Panther or HRD hose rescue device vehicles with foam concentrate, dry chemical and twin-agent capability. The vehicle bay is mechanically ventilated at 6 to 10 ACH for diesel exhaust extraction during vehicle start and warmup, with overhead reel hose drops and HRD hose rescue device storage. Duct material in the vehicle bay is galvanised at 1.2 to 1.6 mm on the SBAL-V galvanised configuration, with TDF rectangular trunk and spiral round branch off the SBFB-1500.

The foam concentrate store is the critical zone undergoing the most significant change in airport ARFF practice. Australian airports are transitioning from legacy AFFF aqueous film-forming foam concentrate (containing PFAS per- and poly-fluoroalkyl substances including PFOS and PFOA, both restricted under the Stockholm Convention and the Australian PFAS National Environmental Management Plan) to F3 fluorine-free foam concentrate that achieves comparable fire suppression performance without the persistent organic pollutant POP residual. The phase-out programme is led by the Department of Defence and CASA in coordination with Airservices Australia and the airport operators.

The foam store ventilation must handle two parallel environments during the transition period. The legacy AFFF store classifies as AS 1940 Class 3 flammable liquid with PFAS-contaminated atmosphere — the duct material is 316L stainless at 1.5 mm because PFAS residuals attack standard galvanised coating, and the SBSF-1525 stitchwelder produces the foam delivery vent stack with continuous stainless TIG-finished seam. The new F3 store classifies as AS 1940 Class 3 without the PFAS exposure — the duct material can step down to galvanised at 1.2 to 1.6 mm but most operators specify 316L throughout the foam store for consistency and future-proofing.

The PFAS exposure framework for the ARFF station includes specific exposure limits and surveillance protocol. PFOS and PFOA have no formal Australian WES but the operator-breathing-zone exposure is managed through dedicated extract ventilation, operator PPE during foam handling and routine blood serum PFAS surveillance for the firefighter cohort. The training and proficiency drill site (typically a fire training ground adjacent to the ARFF station) is a particularly high PFAS exposure environment because the foam is discharged in volume during training, and the training site soil and groundwater PFAS contamination management is a multi-year remediation programme at most Australian airports.

The ARFF station communication and command room runs as ASHRAE TC 9.9 Class A1 mission-critical with the airport emergency command console, the radio voice communication switch and the network gateway to the ATC tower and the airport central operations centre. Acoustic target inside the command room is NC-30 with the surrounding vehicle bay running at NC-45 to NC-55.

Flight catering Gate Gourmet dnata Qantas Catering FSANZ HACCP — ammonia refrigeration and commercial kitchen

The off-airport flight catering facility at Gate Gourmet Sydney Mascot, dnata Catering Sydney Mascot, Melbourne Tullamarine, Brisbane Hamilton, Perth Jandakot, Qantas Catering Mascot Sydney, LSG Sky Chefs and the smaller Cathay Pacific Catering operation runs a HACCP-controlled cook-chill operation feeding 80,000 to 250,000 meals per day across multiple airlines. The facility is typically located 2 to 5 kilometres from the terminal building face on a separate site connected by a dedicated airside service road for the catering truck fleet.

The cold chain operates on R717 ammonia or R744 carbon dioxide CO2 transcritical refrigerant in the bulk store and IQF blast freezer at minus 25 degrees Celsius, with R32 or R454B HFC-blend in the prep, finishing and assembly rooms at 2 to 8 degrees Celsius and 12 to 16 degrees Celsius. Ammonia refrigeration plant under AS/NZS 5149 operates with the bulk receiver, the high-side compressor and the low-side evaporator in a single mechanical plant room, with ammonia leak detection at every 6 metres of refrigerant pipe and AS/NZS 60079 Class I Zone 2 classification within a 3 metre envelope of any ammonia receiver, compressor or pressure vessel. The ammonia WES is 25 ppm STEL with 35 ppm IDLH, and any leak above 25 ppm in the operator breathing zone triggers immediate evacuation of the plant room.

Ammonia ductwork — the ventilation extract from the ammonia plant room and the make-up air supply — is 316L stainless at 1.5 to 2.0 mm with continuous TIG-welded seams. The SBSF-1525 stitchwelder produces the longitudinal seam stitch welding followed by manual TIG full penetration pass for any joint that contains ammonia vapour-bearing air. The make-up air supply is sized for 6 to 10 ACH of the plant room volume to dilute any small ammonia leak below the WES, and the emergency dump exhaust is sized for 60 ACH to clear the plant room to atmospheric in case of a major ammonia release. The emergency exhaust fan is rated for ammonia service with Ex-d Group IIA gas group certification, and the exhaust stack discharges to atmosphere at a roof level minimum 10 metres above the nearest occupied envelope and 30 metres from any building intake.

The commercial kitchen extract under NFPA 96 runs the grease hood at 0.4 to 0.5 m/s capture velocity with UL 300 wet chemical fire suppression and 316L stainless 1.5 mm gauge supply and exhaust ductwork sized for 1,500 to 4,000 L/s per cook line. The cook line at Gate Gourmet, dnata and Qantas Catering handles wok, char-grill, salamander, deep fryer, combi oven, steam kettle, tilting pan, blast chiller and IQF freezer in a continuous production line layout. The grease hood ductwork is fabricated on the SBAL-V 316L variant with continuous welded seams, and the duct envelope is rated for cleaning access every 1.5 metres per AS 1668.1 commercial kitchen ductwork inspection requirements.

The flight catering production area is divided into hot kitchen, cold kitchen, finishing room, assembly room, dishwash and the loading dock for the catering truck connection. The hot kitchen runs at 30 to 35 degrees Celsius peak with high humidity from cooking vapour, requiring high air change rate at 20 to 30 ACH and dedicated kitchen exhaust. The cold kitchen runs at 12 to 16 degrees Celsius for raw protein handling and sandwich assembly, with ASHRAE 62.1 ventilation at 7.5 to 10 L/s/person and HEPA H13 supply air for the open prep area. The finishing room and assembly room run at 2 to 8 degrees Celsius for chilled meal final assembly before catering truck loading, with low air change rate at 4 to 6 ACH and dedicated cooling supply. The dishwash runs at 30 to 40 degrees Celsius with high humidity from the wash and rinse cycle, with dedicated exhaust to manage the steam and detergent aerosol.

The FSANZ HACCP 4.2.1 (general food safety), 4.2.2 (food safety supervisor training) and 4.2.3 (food service to vulnerable population including airline catering) framework governs the entire flight catering operation. Halal certification (Australian Federation of Islamic Councils), Kosher certification (Kashrut Authority of Australia and New Zealand), Vegan and other dietary requirement certification add additional segregation requirements on the production line. The HVAC duct designer must accommodate the segregation through dedicated AHU and dedicated ductwork serving the Halal cook line and the Kosher cook line, with no cross-contamination of supply or return air between the segregated production zones.

Melbourne Airport Rail Sydney AirTrain Brisbane AirTrain — NFPA 130 fixed guideway rail interchange

The terminal-rail interchange is an emerging design challenge at Australian airports. Sydney Airport Train operates the underground Mascot and Domestic stations connecting Sydney T1 International and T2/T3 Domestic to the Sydney CBD through the Eastern Suburbs and Illawarra line. Brisbane AirTrain operates the elevated airport rail link connecting Brisbane International and Domestic terminals to the Brisbane Citytrain network. Adelaide Airport Bus operates the surface bus rapid transit BRT connection. Melbourne Airport Rail is planned for delivery in 2031 with elevated and underground rail tunnels from Sunshine to Tullamarine T1, T2, T3 and T4. Avalon Airport rail is proposed as part of the Geelong Fast Rail programme.

The rail interchange envelope classifies under NCC Class 9b assembly with NFPA 130 fixed guideway transit rail providing the fire and life safety design framework. NFPA 130 mandates emergency ventilation of the rail tunnel and the underground station platform under a worst-case design fire scenario (typically a 7 to 15 MW heat release rate from a rolling stock fire). The station platform smoke spill exhaust must clear the platform envelope to tenability within 6 minutes of alarm activation. AS 1668.2 mirrors most of the NFPA 130 ventilation rate provisions for the Australian transit rail application.

The ductwork specification for the rail interchange combines the terminal building HVAC envelope with the rail tunnel emergency ventilation. The transition between the terminal envelope and the rail station is treated as a fire compartment boundary with 250 degree Celsius / 2 hour fire-rated dampers per AS 1668.1 and AS 1530.4. The terminal HVAC supply does not feed the rail station — the rail station has its own dedicated supply and return AHU sized for the platform occupant load and the rolling stock heat dissipation. The rail tunnel emergency ventilation is a separate system with smoke spill exhaust fans located at strategic intervals along the tunnel run, sized for the design fire scenario.

Duct material in the rail station platform is galvanised at 1.2 to 1.6 mm with continuous welded seams on the SBAL-V galvanised configuration for the rectangular trunk and the SBFB-1500 for the spiral round riser. The smoke spill duct is heavy-gauge galvanised at 1.6 to 2.0 mm with bolted flange joints rated F300/120. The tunnel emergency ventilation duct, where it crosses the tunnel cross-section, is heavy-gauge galvanised at 2.0 to 3.0 mm with welded seams on the SBSF-1525 stitchwelder and manual finish pass.

The Sydney AirTrain underground station at Mascot and Domestic operates the Australian Rail Track Corporation ARTC and Sydney Trains network interface with dedicated electrical isolation, smoke control and emergency ventilation. The Brisbane AirTrain elevated station operates as an open-platform structure with reduced smoke spill requirement because of natural ventilation through the elevated platform geometry. The Melbourne Airport Rail station design (planned 2031 delivery) is mixed elevated and underground depending on the precinct geometry.

SBKJ machine fleet for the Australian airport terminal project

The Australian airport terminal duct fabrication requirement spans the full SBKJ machine portfolio. The complexity arises from the diversity of materials, gauges and geometries within a single project — galvanised at 0.8 to 2.0 mm for the bulk of the terminal HVAC, 316L stainless at 1.5 mm for the flight catering, commercial kitchen, ammonia refrigeration vent stack, apron Zone 1 jet fuel vent stack and ARFF F3 foam delivery, 304L stainless at 1.0 mm for the ATC tower and the SmartGate biometric processing room, and 309S or 310S heavy-gauge stainless at 3 to 6 mm for the FUEL hydrant pipeline external service envelope.

The SBAL-V auto duct line in galvanised configuration handles the bulk of the terminal HVAC supply and return ductwork at 0.8 to 1.2 mm G90 (Z275) coil. The line uses standard TDF flange dies, normal forming pressure, and galvanised-compatible tooling throughout. Single-shift output is 600 to 900 metres of finished duct per shift on typical terminal sizes (600 to 1,800 mm). The cut, notch, fold and TDF flange forming stations operate in sequence at 8 to 15 metres per minute production rate. The SBAL-V galvanised configuration is the workhorse machine for the project, fabricating the supply and return ductwork for the concourse, check-in hall, gate lounge, arrival hall, baggage carousel hall, retail concourse and the back-of-house plant room.

The SBAL-V auto duct line in 316L stainless configuration handles the flight catering kitchen, commercial kitchen and apron Zone 1 ductwork at 1.5 mm 316L coil. The line uses hardened TDF flange dies for stainless work-hardening, upgraded forming pressure for 316L yield strength (485 MPa versus 280 MPa for galvanised), and stainless-compatible tooling throughout. Single-shift output drops to 350 to 500 metres of finished duct per shift because of slower forming and the manual TIG finish pass required for NFPA 96 commercial kitchen and AS/NZS 60079 hazardous area compliance.

The SBAL-III auto duct line handles the wider 1,800 to 2,500 mm international concourse and arrival hall ductwork that exceeds the standard SBAL-V coil width capacity. The SBAL-III is configured for galvanised at 1.0 to 1.6 mm with TDF flange forming at the wider coil width. Single-shift output is 400 to 600 metres of finished duct per shift on the wider sections.

The SBFB-1500 spiral former handles the round ductwork for carpark jet fan, BHS conveyor-side extract, baggage hall capture hood, apron Zone 1 vent stack, ATC tower equipment room and the commercial kitchen riser. The spiral former produces 250 to 1,500 mm diameter at 0.6 to 2.0 mm wall thickness in galvanised, 304L stainless or 316L stainless coil. SMACNA leakage class 6 (under 1% leakage at 1,000 Pa) is the minimum acceptable seal class, and conductive bonding terminals are installed every 6 metres of run for ESD-safe applications including the BHS conveyor-side extract, the apron Zone 1 jet fuel vent stack and the SmartGate biometric processing room.

The SBTF-1500/1602/2020 spiral tubeformer handles the larger 1,500 to 2,000 mm diameter round trunk for the smoke spill riser, the kitchen exhaust riser and the ammonia refrigeration vent stack. The tubeformer produces heavy-gauge round duct at 1.5 to 3.0 mm wall thickness in galvanised or stainless coil with SMACNA leakage class 6.

The SBSF-1525 stitchwelder produces the longitudinal seam welded riser pipe for the smoke spill 250 degree Celsius / 2 hour fire-rated duct, the ammonia refrigeration vent stack, the ARFF F3 foam delivery vent and the apron Zone 1 jet fuel vent stack. The stitchwelder handles 2 to 6 mm wall thickness in galvanised or stainless coil with continuous longitudinal seam stitch welding and manual MIG/MAG or TIG finish pass. Production rate is 4 to 10 metres of finished riser per shift depending on size and wall thickness, with dye penetrant inspection DPI at every joint and pressure test at 1.5 times design pressure for 30 minutes.

The SBPC1500 plasma cutting table handles the heavy-gauge 309S or 310S stainless plate at 3 to 6 mm wall thickness for the FUEL hydrant pipeline external service envelope. The plasma table cuts the plate at 0.8 to 2.5 metres per minute travel speed depending on plate thickness, with full continuous bevel preparation for the manual TIG welding at every joint. The 309S filler rod and 310S filler rod selection matches the parent material for the hydrant pipeline service envelope.

The SBLR-600 laser cutter handles the precision cut for the access door, the inspection panel and the small duct branch fitting that requires tight tolerance (typically plus or minus 0.2 mm) on the cut edge. The laser cutter handles galvanised, 304L stainless and 316L stainless plate at 0.6 to 6 mm wall thickness, with edge quality suitable for direct welding without additional preparation.

The SB-ZF1500 z-lock former produces the longitudinal seam z-lock for the rectangular galvanised duct trunk where the SBAL-V auto duct line is not the chosen machine (typically for very large one-off duct sections that don't fit the SBAL-V coil width, or for retrofit work where the existing duct envelope requires hand-formed sections). The z-lock former handles 0.8 to 1.6 mm galvanised coil.

SBKJ machine application matrix for the Australian airport terminal portfolio

The application matrix below summarises the SBKJ machine selection across the eight terminal process zones and the apron-side and back-of-house envelopes. The matrix is the same engineering reference our SBKJ application team uses when scoping a new airport terminal project.

Terminal HVAC supply and return ductwork (0.8 to 1.2 mm galvanised, 600 to 1,800 mm rectangular trunk). Primary machine: SBAL-V galvanised configuration. Secondary machine: SBAL-III for the wider 1,800 to 2,500 mm sections. TDF flange forming, SMACNA pressure class 1,500 to 2,500 Pa, seal class A. Production rate 8 to 15 metres per minute, single-shift output 600 to 900 metres of finished duct.

Flight catering kitchen and commercial kitchen ductwork (1.5 mm 316L stainless, 300 to 1,200 mm rectangular trunk). Primary machine: SBAL-V 316L stainless configuration with hardened TDF dies, upgraded forming pressure and stainless-compatible tooling. NFPA 96 grease hood specification, FSANZ HACCP 4.2.1/4.2.2/4.2.3 compliance, UL 300 wet chemical fire suppression. Production rate 4 to 8 metres per minute, single-shift output 350 to 500 metres.

Carpark jet fan, BHS conveyor-side extract, baggage hall capture hood, ATC tower equipment room (1.0 to 1.5 mm galvanised or 316L stainless, 250 to 1,500 mm round spiral). Primary machine: SBFB-1500 spiral former. ESD-safe conductive bonding every 6 metres for the BHS and apron applications. SMACNA leakage class 6 (under 1% at 1,000 Pa). Production rate 12 to 25 metres per minute.

Smoke spill riser, kitchen exhaust riser, ammonia refrigeration vent stack (1.5 to 3.0 mm galvanised or 316L stainless, 1,500 to 2,000 mm round trunk). Primary machine: SBTF-1500/1602/2020 spiral tubeformer. Secondary machine: SBSF-1525 stitchwelder for the smaller 800 to 1,200 mm riser. F300/120 smoke spill rating per AS 1668.1, AS/NZS 5149 ammonia service for the catering vent.

Smoke spill 250 C / 2 hr fire-rated duct, ARFF F3 foam delivery vent, apron Zone 1 jet fuel vent stack (2 to 6 mm 316L stainless, 400 to 1,500 mm round riser). Primary machine: SBSF-1525 stitchwelder with continuous longitudinal seam welding and manual TIG finish pass. Dye penetrant inspection DPI at every joint, pressure test at 1.5 times design pressure for 30 minutes. AS/NZS 60079 hazardous area certification for the apron and the ARFF applications.

FUEL hydrant pipeline external service envelope (3 to 6 mm 309S or 310S heavy-gauge stainless, 600 to 1,200 mm round riser). Primary machine: SBPC1500 plasma cutting table for plate cutting and bevel preparation, manual TIG welding for the assembly. 309S or 310S filler rod matching the parent material. AS/NZS 60079 Zone 1 hazardous area certification for the entire envelope.

ATC tower controller cab and SmartGate biometric processing room (0.8 to 1.0 mm 304L stainless, 400 to 800 mm rectangular trunk and 250 to 600 mm round branch). Primary machine: SBAL-V 304L stainless configuration. Acoustic NC-25 in the ATC controller cab achieved through low-velocity supply, acoustic lining and spring isolation. Mission-critical ASHRAE TC 9.9 Class A1 environment.

Access door, inspection panel and small duct branch fitting (precision cut, 0.6 to 6 mm wall thickness). Primary machine: SBLR-600 laser cutter for the precision cut requirement. Tolerance plus or minus 0.2 mm on the cut edge.

Operator and asset value at risk in the Australian airport portfolio

The Australian airport operator network is the most concentrated and capital-intensive in commercial aviation outside the US, with the major capital city airports operating under private ownership consortia involving global infrastructure investment funds, superannuation funds and trade infrastructure operators. The HVAC duct designer should understand the asset value at risk because the project specifications and the contract liability framework reflect the underlying asset value.

Sydney Kingsford Smith Airport YSSY is operated by Sydney Airport Corporation Limited covering T1 International, T2 Domestic and T3 Domestic. Sydney Airport was Australia's largest at 44 million passengers in 2019, hosting Star Alliance, Oneworld and SkyTeam member airlines. Sydney Airport was privatised in 1998 and listed on the ASX as Sydney Airport Holdings, delisted 2022 after a private acquisition by an IFM Investors and Global Infrastructure Partners consortium. The total asset value at risk is approximately 32 billion Australian dollars.

Melbourne Tullamarine Airport YMML is operated by Australia Pacific Airports Corporation APAC covering T1 Qantas Domestic, T2 International, T3 Virgin Domestic and T4 Jetstar Domestic. Melbourne Airport was Australia's second-largest at 37 million passengers in 2019. Ownership is split between IFM Investors and APG (Stichting Pensioenfonds ABP) under the Australia Pacific Airports Corporation banner.

Brisbane Airport YBBN is operated by Brisbane Airport Corporation BAC covering T1 Domestic and T2 International. Brisbane Airport was Australia's third-largest at 24 million passengers in 2019. Ownership is split between Schiphol Group, IFM Investors and Marubeni Corporation.

Perth Airport YPPH is operated by Perth Airport Pty Ltd covering T1 International, T2 International, T3 Domestic and T4 Domestic. Perth Airport handled 14 million passengers prior to the iron ore commodity cycle peak. Ownership is split between IFM Investors and AustralianSuper.

Adelaide Airport YPAD operated by Adelaide Airport Limited handled 5.6 million passengers prior to 2020. The terminal opened in 1995 with subsequent expansions covering T1 International and Domestic plus a general aviation precinct. Cairns Airport YBCS operated by Cairns Airport Pty Ltd under North Queensland Airports NQA covers international, domestic and general aviation. Darwin International Airport YPDN operated by Northern Territory Airports covers international, domestic and a joint-use defence interface with RAAF Tindal. Hobart International Airport YMHB operated by Hobart Airport Pty Ltd under Macquarie Group ownership covers domestic and limited international. Canberra Airport YSCB operated by Capital Airport Group covers domestic, limited international and defence cross-over with RAAF Fairbairn and the Air Canberra GA precinct. Avalon Airport YMAV is Linfox-owned, located in Geelong VIC, operating as a Jetstar and AirAsia LCC base plus secondary GA and low-cost carrier operations.

The general aviation airport network at Bankstown YSBK, Camden, Essendon YMEN, Moorabbin YMMB and Archerfield YBAF operates as training school, flying club, helicopter base and corporate jet operation hubs. These airports operate with smaller terminal envelopes and reduced ARFF coverage, but the same regulatory framework applies under CASA CASR Part 139 (with reduced category coverage for the GA-only operations).

The airline operator network includes Qantas Airways ASX:QAN (the flag carrier and largest international and domestic operator), Jetstar Group (Qantas low-cost subsidiary), Virgin Australia (Bain Capital-owned following the 2020 administration and restructure), Rex Airlines Regional Express (regional operator), and Bonza Airlines (closed 2024). The international airline alliance partner network at Sydney, Melbourne, Brisbane and Perth includes Star Alliance (Singapore Airlines, ANA All Nippon Airways, Lufthansa, Air New Zealand, United Airlines, Asiana, Turkish Airlines), Oneworld (Cathay Pacific, Qantas, Qatar Airways, Iberia, Royal Jordanian, British Airways, Alaska Airlines, American Airlines AA), and SkyTeam (KLM, Air France, Delta, Korean Air, ITA Airways, Vietnam Airlines, Garuda Indonesia).

The ground handling and cargo operator network includes Menzies Aviation, dnata Airport Services, Aerocare, Australian Air Express, Australian Customs, Border Force, AFP, the Department of Home Affairs, and AQIS Biosecurity. The cargo and courier operator network includes DHL, FedEx, TNT (now part of FedEx Express following the 2016 acquisition), UPS, Toll IPEC, StarTrack (Australia Post), and Quantum Aviation.

The construction and major contractor network includes Lendlease, Multiplex, Watpac, Hutchinson Builders, John Holland, Acciona, Built, Mirvac Property, and Dexus. The HVAC duct subcontractor on a major terminal expansion typically sits two to three tiers below the head contractor, with the project superintendent and the building services engineer providing the daily interface during fit-out.

Standards stack for Australian airport terminal HVAC ductwork

The full standards stack for Australian airport terminal HVAC ductwork is the most extensive of any commercial sector. The duct designer cross-references the following standards on every project.

AS 1668.1 Smoke spill systems for buildings, sections 5, 6 and 7 covering smoke spill system design, smoke spill duct fire rating and F300/120 smoke spill fan rating. AS 1668.2 Mechanical ventilation in buildings, section 4 covering carpark CO ventilation and section 3 covering general ventilation rates. AS 1668.3 Zoned smoke control covering the open-volume concourse and check-in hall. AS 4254 Ductwork construction for HVAC, AS 4254.1 flexible ductwork and AS 4254.2 medium-pressure galvanised ductwork. AS 1530.4 Fire resistance tests of elements of construction covering the 250 C / 2 hr and 250 C / 4 hr smoke spill duct rating.

AS/NZS 60079.10.1 Hazardous area classification covering the apron Zone 1 jet fuel envelope, fuel farm Zone 0/1/2 envelope and the Li-ion BESS thermal runaway Zone 2 envelope. AS/NZS 60079.14 Electrical installations in hazardous areas covering the equipment certification and installation requirements. AS 1940 Storage and handling of flammable and combustible liquids covering jet fuel, AVGAS, diesel and propane storage. AS 4332 Specialty gas handling covering oxygen, nitrogen and acetylene at the fuel servicing and maintenance interface.

AS 1428.1 Design for access and mobility, general requirements covering passenger accessibility and the DDA Disability Discrimination Act compliance. AS 1428.2 Wheelchair accessible cubicle. AS 1428.4 Wayfinding tactile indicator. AS 1735 Lift, travelator, moving walkway and escalator covering the vertical transport interface, with AS 1735.16 specifically covering the escalator dimensioning.

NFPA 415 Aircraft fuel servicing ramps and drainage covering the apron fuel servicing zone. NFPA 416 Aircraft fueling vehicle covering the refueller tanker. NFPA 418 Aircraft refuelers at heliports. NFPA 409 Aircraft hangar (where the terminal building includes an adjacent hangar element). NFPA 13 Standard for sprinkler systems. NFPA 14 Standard for standpipe systems. NFPA 70 National Electrical Code NEC. NFPA 75 Information technology equipment. NFPA 96 Standard for commercial cooking facility ventilation. NFPA 130 Fixed guideway transit rail covering the terminal-rail interchange at the Sydney AirTrain, Brisbane AirTrain and the planned Melbourne Airport Rail.

ICAO International Civil Aviation Organization Annex 14 Aerodrome. ICAO Annex 17 Security. ICAO Annex 18 Dangerous goods by air. ICAO Doc 9137 Airport Services Manual. ICAO Doc 9981 Airport Master Plan. CASA Civil Aviation Safety Authority CASR Part 139 aerodrome certification covering the obstacle limitation surface, visual aids, runway, taxiway, apron and terminal building access.

NCC National Construction Code Class 9b assembly (terminal concourse, check-in, gate lounge, arrival hall, baggage carousel), Class 5 office (back-of-house airline office and Border Force office), Class 6 retail (duty free and concession retail), Class 7a carpark (terminal carpark and park+ride+priority+valet), Class 7b storage (BHS baggage hall and cargo terminal), Class 8 industrial (flight catering and ARFF station), Class 9a healthcare (medical clinic and first aid).

AS/NZS 1158 Lighting for roads and public spaces (apron and taxiway lighting interface). AS/NZS 3666.1, 3666.2 and 3666.3 Microbial control of air handling and water systems including Legionella prevention. ASHRAE 62.1 Ventilation for acceptable indoor air quality (8 L/s/person passenger area, 15 L/s/person concourse, 12 L/s/person check-in, 7.5 L/s/person retail). ASHRAE 90.1 Energy standard for buildings. NABERS National Australian Built Environment Rating System for terminal energy and indoor environment quality. Green Star and WELL Building Standard for the major terminal expansion projects. ASHRAE 170 Ventilation of healthcare facilities (medical clinic and first aid). AS/NZS 2107 Acoustics target ranges (NC-25 prayer room and ATC controller, NC-30 SmartGate biometric and airline crew, NC-35 concourse and retail, NC-45 baggage hall, NC-55 plant room).

Aviation Transport Security Act 2004 and Aviation Transport Security Regulations 2005 covering ASIC Aviation Security Identification Card and the airside access framework. AQIS Biosecurity Act 2015 covering biosecurity inspection, quarantine zoning and HEPA exhaust requirements. Privacy Act 1988 and APPs Australian Privacy Principles covering the Border Force, SmartGate and surveillance camera data handling. FSANZ Food Standards Australia New Zealand 4.2.1, 4.2.2 and 4.2.3 covering food court, duty free food retail, catering and flight catering operations.

AS 4587 Anti-vandal envelope covering the public-side and secure-side boundary. AS 5132 Indoor air quality covering the terminal operating indoor air quality framework. AS 4187 Sterile reprocessing covering the medical clinic and first aid sterile equipment handling. AS 4326 Refrigerated transport (the airside catering truck and refueller tanker refrigeration interface).

Workplace Exposure Standards WES across the terminal envelope

The Workplace Exposure Standards WES applicable to the airport terminal envelope are the most diverse of any commercial sector. The HVAC duct designer must understand the WES exposure framework because the ventilation rate design and the local capture specification all back-calculate from the WES.

Jet fuel JP-8 and AVTUR Jet A-1 kerosene at 200 ppm with benzene at 1 ppm STEL as the killer aromatic exposure (apron, ramp, fuel servicing zone, apron stand, aerobridge connection). Petroleum hydrocarbon as decane 200 ppm with nC9 to nC16 paraffin contributing to the total hydrocarbon load. AVGAS 100LL lead inorganic at 0.05 mg/m cubed for the legacy general aviation and piston aircraft service at Pearce WA, Edinburgh SA, Avalon, Bankstown, Essendon, Moorabbin and Archerfield. Particulate diesel exhaust at 0.1 mg/m cubed elemental carbon DPM, with ultrafine particulate and PM2.5 at 10 mg/m cubed acute exposure (ground support equipment GSE, tug, tow bar, air-start, power-up, refueller, baggage tug, catering truck, ambulance lift, ramp vehicle).

CO carbon monoxide at 30 ppm STEL and NO2 nitrogen dioxide at 5 ppm STEL (vehicle exhaust at apron and ramp, commercial kitchen and commercial KP). CO2 carbon dioxide at 5000 ppm TWA (passenger respiration in the high-density concourse, retail, commercial kitchen and catering during peak passenger density and peak meal service). Particulate PM2.5 10 mg/m cubed, PM10 20 mg/m cubed and inhalable 50 mg/m cubed (jet engine exhaust, vehicle exhaust, apron tyre wear, bushfire smoke during the Australian fire season and the dust storm episodes affecting Adelaide, Newcastle and Sydney typically September to November).

Refrigerant exposures include R32 and R454B (HFC blends used in chiller plant and split-system air conditioning), R744 carbon dioxide CO2 transcritical refrigerant (the emerging low-GWP alternative for commercial refrigeration), and R717 ammonia at 25 ppm STEL (the bulk store refrigerant at flight catering, vaccine fridge, blood bank, commercial kitchen and chilled water plant where ammonia is selected over HFC). Formaldehyde at 1 ppm STEL (preservative chemistry, new fit-out, MDF and laminate, duty free perfume and packaging). VOC general (duty free perfume, alcohol, cosmetic, retail, paint, adhesive, aerosol). NH3 ammonia at 25 ppm STEL (refrigeration plant, commercial kitchen, flight catering, ASHRAE 62.1 baseline).

Cl2 chlorine at 0.5 ppm, peracetic acid at 0.4 ppm, ClO2 chlorine dioxide at 0.1 ppm and ozone at 0.1 ppm STEL (commercial pool spa adjacent rare, COVID disinfection, UV and HVAC sanitisation post-COVID). HF hydrogen fluoride at 1.8 ppm STEL (Li-ion BESS thermal runaway, ULD unit load device container fire, aircraft lithium-ion battery cargo fire). HCN hydrogen cyanide at 5 ppm STEL (rare emergency fire scenario, aircraft interior fire, baggage fire, ULD fire). CH4 methane at 1.25% LEL (LPG kitchen, propane, natural gas heating, flight kitchen LPG).

Aircraft de-icing fluid ADAF Type I, II, III and IV ethylene glycol and propylene glycol contributes a runoff RDF residual de-icing fluid load at the limited Australian de-icing operations — Hobart YMHB, Canberra YSCB and occasionally Adelaide YPAD during the rare winter frost conditions. The de-icing operation is not a year-round Australian airport issue (unlike the European and North American airports where de-icing dominates winter operations), but the duct designer must accommodate the seasonal de-icing run-off and the deluge wash-down of the apron in the de-icing capable airports.

Commissioning and handover for the Australian airport terminal HVAC ductwork

The commissioning sequence for the Australian airport terminal HVAC ductwork is among the most complex in commercial building practice because of the parallel security, biosecurity and operational tempo constraints. The HVAC duct contractor cannot freely access the airside envelope during commissioning — ASIC clearance is required for the installation team and the commissioning team, and the airside access is subject to the airport operations centre and the airline schedule.

The commissioning sequence typically starts with air-balance per AS/NZS 5443 to within plus or minus 5% of design flow on the terminal supply and plus or minus 10% on the exhaust. The smoke spill system commissioning includes a hot-smoke test at the worst-case fire scenario, verifying the zoned smoke control performance against the AS 1668.3 tenability brief. The hazardous area inspection to AS/NZS 60079.14 covers every electrical penetration through the apron-side ductwork, the fuel farm ductwork, the BHS ESD-safe ductwork, the flight catering ammonia plant ductwork and the ARFF station ductwork.

The fire engineering brief verification covers the AS 1668.1 250 C / 2 hr smoke spill duct rating, the F300/120 smoke spill fan rating, the AS 1530.4 fire resistance level of the duct construction and insulation, and the AS 4254 ductwork construction class. The DDA AS 1428.1 verification covers every wall-mounted diffuser, return grille and access panel within reach range of a passenger.

The handover documentation includes as-built drawings, weld procedure qualification records WPQR for every welded section of the smoke spill riser and the apron Zone 1 ductwork, pressure test certificates for every welded vessel, dye penetrant inspection DPI reports for every smoke spill duct joint, hazardous area inspection certificates per AS/NZS 60079.14, ASIC-cleared installation contractor records per Aviation Transport Security Regulations 2005, and the operating and maintenance manual covering the duct cleaning schedule per AS 1668.1 commercial kitchen inspection requirements (typically 1.5 metre access intervals along the kitchen exhaust ductwork).

The operational tempo constraint means that most major terminal HVAC ductwork installation work is performed during the overnight curfew window (typically 11pm to 6am at Sydney YSSY under the Sydney Airport Curfew Act 1995, with similar curfew arrangements at Adelaide YPAD and Essendon YMEN). The duct contractor cannot perform noisy or disruptive work during the peak passenger hours, and the work must be completed and the work area cleared before the early morning departure push. This constraint extends the project duration significantly compared with a non-airport commercial fit-out, and the HVAC duct contractor must factor the curfew constraint into the project programme.

Lead time and the SBKJ engineering support model

For a greenfield airport terminal expansion or refurbishment, the SBKJ machine fleet lead time is 18 to 24 weeks from purchase order to commissioning of duct fabrication on site. The SBAL-V auto duct line in galvanised configuration ships 12 to 14 weeks. The SBAL-V in 316L stainless variant for flight catering and apron Zone 1 jet fuel ships 14 to 16 weeks. The SBAL-III for the wider 1,800 to 2,500 mm international concourse duct ships 14 to 16 weeks. The SBFB-1500 spiral former for carpark jet fan, BHS and apron exhaust ships 10 to 12 weeks. The SBTF-1500/1602/2020 spiral tubeformer for the larger 1,500 to 2,000 mm diameter round trunk ships 10 to 12 weeks. The SBSF-1525 stitchwelder for smoke spill 250 C / 2 hr riser, ammonia refrigeration vent stack and ARFF F3 foam delivery ships 12 to 14 weeks. The SBPC1500 plasma table for heavy gauge 309S/310S FUEL hydrant pipeline external service envelope ships 8 to 10 weeks. The SBLR-600 laser cutter for precision access door and inspection panel cut ships 8 to 10 weeks. The SB-ZF1500 z-lock former for hand-formed retrofit sections ships 6 to 8 weeks.

Add 4 to 6 weeks ocean freight to Australian ports and 1 to 2 weeks for installation, mechanical commissioning and operator training by SBKJ engineers from our Box Hill North VIC service base. The Australian engineering support team operates from the Box Hill North office covering Melbourne metropolitan and Victorian regional projects, with field service capability to all Australian capital city airports and regional GA airports through our project mobilisation team.

ARBS 2026 May Sydney is the practical venue for live demonstration of the SBKJ machine families with our application team available for project scoping discussions. We will exhibit the SBAL-V auto duct line, the SBFB-1500 spiral former, the SBSF-1525 stitchwelder and the SBPC1500 plasma table at the stand, with the SBAL-III, SBTF, SBLR and SB-ZF available for separate demonstration on request. The ARBS show floor is the most practical opportunity for the Australian airport operator HVAC procurement team to see the machines running, discuss the project scoping with the SBKJ engineering team, and review the application matrix against the specific airport terminal project requirements.

Contact SBKJ Group for Australian airport terminal HVAC ductwork project scoping

The SBKJ Group is an Australian-positioned HVAC duct fabrication machinery specialist based at Box Hill North VIC, supplying the airport terminal, passenger processing, BHS baggage handling, air traffic control, Border Force, AQIS biosecurity, duty free retail, flight catering and ARFF aircraft rescue fire fighting ductwork market across Australia and the wider Asia-Pacific region. Our SBAL-V, SBAL-III, SBSF-1525, SB-ZF1500, SBFB-1500, SBPC1500, SBLR-600 and SBTF-1500/1602/2020 machine families cover the full Australian airport terminal duct fabrication requirement from passenger concourse galvanised through flight catering 316L stainless to the apron Zone 1 jet fuel and ARFF F3 foam delivery hazardous-area service envelope.

For project scoping, machine specification, lead time confirmation and engineering support across the Australian airport terminal HVAC ductwork project portfolio, contact our sales and application engineering team.

SBKJ Group — Box Hill North VIC
Email: sales@sbkjduct.com
Phone: +61 435 074 994
Web: sbkjduct.com
ARBS 2026 May Sydney — live machine demonstration and project scoping discussion at the SBKJ stand.

All specifications in this guide reference Australian Standards (AS, AS/NZS) and NFPA where Australian Standards mirror the international reference. The SBKJ engineering team is available to review specific project requirements and confirm the machine selection against the project HVAC ductwork specification.