Why roadside infrastructure is the densest HVAC scope in the Australian market
Roadside infrastructure looks deceptively simple from the passenger seat — a row of fuel dispensers under a steel canopy, a small convenience store, a brick amenity block at the edge of the carpark, an EV charging cabinet on a fresh patch of bitumen, and on long-haul routes a sprawling roadhouse with motel rooms and a kitchen open until midnight. Engineer the HVAC ductwork inside and around any of these footprints and the complexity reveals itself quickly. A single 1,500 m² service station combined with an EV charging hub stacks five distinct hazardous-area classifications, three independent ventilation regimes, a fire-rated grease exhaust system, an accessible-toilet exhaust, a forecourt vapour recovery line, an LPG cylinder cage exhaust, and — if hydrogen refuelling is on the masterplan — a fourth hazardous area an order of magnitude wider than any of the others. A remote roadhouse on the Stuart or Eyre Highway adds a commercial kitchen running ten hours a day, a 12–30 room motel, a laundry, a beer garden, and a primary diesel-generator power station. A council-operated public toilet at a Surf Coast carpark looks straightforward until you map the AS 1428.1 accessibility envelope, the parents’ room baby-change exhaust, the corrosive sea-air specification for the duct material, and the 24/7 unmanned operation that drives reliability ahead of cost.
The HVAC duct contractor or fabricator who walks onto any of these footprints without a structured grasp of the overlapping codes — AS 1668.2 for ventilation rates, AS/NZS 60079 for hazardous areas, AS 1940 for flammable liquid storage, AS 1596 for LPG, AS 1428.1 for accessibility, AS/NZS 5139 for lithium battery storage, AS 1668.1 for kitchen exhaust, and the layered NFPA 30A and NFPA 855 reference codes that almost every multinational operator drops into their head-office specification — will burn weeks in clarification requests and risk rework that delays site reopening. For a fuel retail operator every day a forecourt is closed costs the operator direct retail margin; for a public toilet operator the cost is reputational; for a roadhouse operator on the Eyre Highway between Norseman and Border Village the cost is safety, as there is no second roadhouse to switch traffic to.
This guide consolidates what SBKJ engineers have learned across two decades of HVAC duct machinery and ductwork fabrication work supporting Australian roadside infrastructure projects. The audience is HVAC contractors, sheet-metal fabricators and design consultants tendering or pricing roadside work, plus asset managers and project leads inside Australian fuel retail majors, EV charging networks, hydrogen pilot operators, motorway service plaza concessionaires and local government authority public-toilet programmes. ARBS 2026, the Air Conditioning, Refrigeration and Building Services trade show running at the International Convention Centre Sydney from May 19–21, 2026, is the single most concentrated meeting point for this sector — SBKJ exhibits as Stand 236 under the Australia Ducting Pty Ltd entity.
Section 1 — The Australian roadside-infrastructure landscape in 2026
The Australian roadside infrastructure market in 2026 sits at the intersection of three structural shifts. First, fuel-retail consolidation has left eight branded networks accounting for roughly 90 percent of the country’s 6,800 service stations. Second, the EV-charging rollout is now in its first credible build-out phase, with Chargefox, Tesla Supercharger, Evie Networks, NRMA EV Fast Chargers, JOLT, Ampol AmpCharge and BP Pulse all running multi-site programmes that have moved Australia from roughly 600 public DC fast charge points in 2022 to a target above 5,000 by 2030. Third, the highway and rest-stop refurbishment cycle — driven by Transport for NSW, VicRoads, Queensland TMR, Department for Infrastructure and Transport SA, Main Roads WA, DSG Tasmania, DIPL NT, and Transport Canberra and City Services ACT — is delivering upgraded amenity blocks at every driver-reviver site, every certified truck driver fatigue facility and every reconstructed motorway service plaza on the Pacific, Hume, Newell, Eyre, Stuart and Bruce highways.
Public toilet and amenity block operators
Public toilets in Australia are predominantly operated by local government authorities (LGAs), with a long tail of national park, state forest, beach trust, surf life saving club, sports club, school, shopping centre and church operators. The 537 LGAs listed by the Australian Local Government Association each operate between 5 and 200+ public toilets, totalling above 20,000 amenity blocks nationally. National Parks & Wildlife Services in each state operate a further 4,000+ blocks at trailheads, picnic grounds and campsites. Beach trusts operate coastal amenity blocks at Bondi, Bronte, Coogee, Manly, Cronulla, Wollongong, Newcastle, Byron, Noosa, Surfers Paradise, Glenelg, Cottesloe, Scarborough, Burleigh Heads and St Kilda. Department of Transport rest stops and motorway service plazas add another 800+ blocks along major highways.
The HVAC scope on a council-operated amenity block is constrained by 24/7 unmanned operation, vandal-resistance, the AS 1428.1 accessibility envelope, the AS 1428.2 ambulant cubicle, parents’ room with baby change, all-gender or family bathroom design, and cultural appropriateness consultation for indigenous community use. For a coastal amenity block within 5 km of salt-air atmosphere the duct material specification jumps from galvanised G275 to 304 stainless or aluminised steel.
Petrol and diesel service station chains
Ampol Limited (ASX:ALD) operates roughly 1,900 sites and is the largest branded network, owns the Lytton refinery in Brisbane, and runs AmpCharge EV charging on a growing subset of metro and highway sites. BP Australia operates approximately 1,500 sites under the BP and BP Reddy Cafe convenience banner, with BP Pulse EV fast-charging rolling out at metro sites. 7-Eleven Australia is the largest convenience-store chain with around 720 forecourt-and-convenience sites. Viva Energy (ASX:VEA), an integrated refiner-marketer owning the Geelong refinery, operates the Shell Coles Express network of around 700 sites and bought out the Coles Group retail tenancy in 2023. United Petroleum (around 500 sites) is an Australian-owned independent with a strong franchise model in regional Victoria, NSW and SA. Liberty Oil (around 350 sites) is concentrated in regional Australia with a higher diesel mix. Mobil Australia exited retail in 2021 with the Altona refinery converting to import terminal operations.
Puma Energy Australia (owned by Trafigura, around 350 sites) has a strong mining and commercial-customer presence in WA, NT and Queensland. Reliance Petroleum is a privately held regional operator. Costco Wholesale operates member-only fuel stations colocated with warehouse stores in Sydney, Melbourne, Brisbane, Adelaide and Perth. IGA Express operates a small number of independent grocer co-located sites. Z Energy has a limited Australian presence. The peak body for independent service stations is the Australasian Convenience and Petroleum Marketers Association (ACAPMA).
Truck stops and roadhouses
Truck stop and roadhouse infrastructure ranges from BP Truck Stop and Shell Truck Stop sites along the Hume, Pacific, Newell, Bruce and Stuart highways through to remote Eyre Highway roadhouses crossing the Nullarbor — Norseman, Balladonia, Caiguna, Cocklebiddy, Madura, Eucla, Border Village, Nullarbor, Yalata, Nundroo, Penong, Ceduna. The Stuart Highway between Adelaide and Darwin adds Pimba, Coober Pedy, Marla, Kulgera, Erldunda, Stuarts Well, Aileron, Ti Tree, Wycliffe Well, Wauchope, Renner Springs, Three Ways, Banka Banka, Larrimah, Daly Waters, Mataranka, Adelaide River and Hayes Creek. The Great Northern Highway, Outback Way, Tanami Track, Strzelecki Track and Birdsville Track add more single-operator roadhouses where one diesel-generator power source serves fuel, food, motel, laundry, shower and emergency services.
The HVAC scope on a remote roadhouse is significantly larger than a metro service station: commercial kitchen exhaust to AS 1668.1 running 12–14 hours a day, a 10–30 room motel section, laundry handling combustion-appliance flues and dryer venting, beer garden or licensed bar smoke management zone if enclosed, separate male and female public showers, B-Triple truck parking with a separate driver fatigue amenity block, and underground fuel storage with full Zone 1 vapour recovery. The Eucla, Cocklebiddy, Border Village, Penong, Marla, Coober Pedy, Renner Springs, Three Ways, Banka Banka, Daly Waters, Mataranka, Borroloola and Roper Bar roadhouses all run primary diesel-generator power.
Motorway service plazas, rest stops and driver fatigue facilities
Motorway service plaza concessions in Australia are limited compared to the European model. HMSHost Australia (subsidiary of Autogrill) runs Sydney Airport food retail and selected highway service centres; NewRest Australia and SSP Australia operate other motorway service plaza tenancies. Highway rest stops operated by state main roads agencies add another 800+ unmanned amenity blocks along major highways. Heavy vehicle driver fatigue facilities certified under the National Heavy Vehicle Regulator (NHVR) Heavy Vehicle National Law require a 15-minute break every 5 hours, a 30-minute break every 7 hours, and a 7-hour continuous rest break every 24 hours for solo drivers. The 200+ certified facilities include B-Triple parking, separate male and female amenity blocks, shower facility, kitchen and dining area, and a sleeping pavilion.
EV charging hubs and networks
Tesla Supercharger Australia is the fastest-growing premium network with over 100 station sites and 700+ charge stalls, V3 (250 kW) and V4 (350 kW). Chargefox (Carsales-acquired) is the largest public network by site count with 1,000+ charge points across 400+ sites including ultra-rapid 350 kW hubs on the Hume, Pacific and Eyre highways. Evie Networks (St Baker Energy Group) operates 300+ charge points across 100+ sites focused on Pacific, Hume, Bruce and Sturt highways. NRMA EV Fast Chargers (NSW NRMA member-benefit) operates 70+ sites in NSW and the ACT. JOLT runs a free-charging model offering 7 kWh per session at 80+ sites. Ampol AmpCharge (50+ sites) and BP Pulse (30+ sites) are growing forecourt-colocated networks. Tritium DCFC is the largest Australian-headquartered DC fast charger manufacturer; Evnex, ChargePoint Australia, Schneider Electric EV and EV Power Australia operate smaller networks. The Electric Vehicle Council is the peak industry body.
HVAC scope on an EV charging hub is modest. The fast-charging equipment cabinet is supplied with integrated liquid cooling by the OEM (Tritium, ABB, Kempower, Schneider, Hitachi ABB Energy, Tesla). The surrounding hub requires equipment-building HVAC for transformer and switchgear, optional waiting-area ventilation if a driver lounge is enclosed, and increasingly a BESS battery-support cabinet for peak shaving (see the SBKJ EV charging and BESS guide for focused reference).
Hydrogen refuelling stations
Hydrogen refuelling station (HRS) infrastructure is in pilot scale, with fewer than ten operating public stations. Coregas Hydrogen operates a 350 bar and 700 bar HRS at Yennora NSW. ATCO operates the Jandakot WA pilot. Fortescue operates a demonstration HRS at Williamtown NSW. Toyota Mirai Australia draws hydrogen from Coregas Yennora and Toyota Centre Altona. BP Hydrogen and Shell Hydrogen have announced planned pilots. Hyzon Motors and H2X (Australian hydrogen vehicle manufacturer at Port Kembla NSW) operate development HRS infrastructure for fleet testing.
HVAC scope on a HRS is the most demanding in the roadside category. Hydrogen has ignition energy roughly an order of magnitude lower than petrol vapour, a 4–75 percent flammable range, and a Zone 1 envelope of 6 m horizontal and 3 m vertical from the dispenser nozzle — significantly wider than the 4.5 m and 1.2 m envelope around a petrol dispenser. SBKJ specifies 304 stainless steel duct for all HRS vent and purge lines, IECEx Ex-d ATEX motors and spark-resistant aluminium impeller fans throughout, nitrogen purge connections before commissioning, and continuous H2 leak detection at high level. See the SBKJ hydrogen production, electrolyser, ammonia and H2 refuelling HVAC duct guide for the production-side scope.
Section 2 — The regulatory stack: which Australian standard applies where
The HVAC duct contractor on a roadside-infrastructure project operates inside a layered regulatory envelope. The following stack applies to every Australian scope — toilet, forecourt, roadhouse, EV hub, hydrogen station — in descending order of severity.
AS/NZS 60079 series — Electrical installations in hazardous areas
The AS/NZS 60079 family (adopted from IEC 60079) is the governing code for hazardous-area classification. AS/NZS 60079.10.1 covers explosive gas atmospheres and is used to draw Zone 0, Zone 1 and Zone 2 envelopes around fuel dispensers, vent stacks, tank fills, breather risers, LPG cylinder cages, hydrogen dispensers and generator exhaust manifolds. AS/NZS 60079.0 covers general Ex-rated equipment requirements; AS/NZS 60079.1 (flameproof), .2 (pressurised), .7 (increased safety) and .11 (intrinsic safety) cover the protection methods. Any fan motor, control device or junction box in Zone 1 or Zone 2 must be IECEx Ex-d ATEX-rated, every duct passing through a hazardous zone must be electrically continuous and bonded to earth, and any spark-producing tool requires a documented hot-work permit.
Zone 0 is continuous-presence (interior of an underground fuel storage tank or vapour recovery line). Zone 1 is normal-operation (within 4.5 m horizontal and 1.2 m vertical of a fuel dispenser, the interior of an enclosed LPG cage, and within 6 m horizontal of a hydrogen dispenser). Zone 2 is abnormal-operation (from the Zone 1 boundary out to 7.5 m horizontal of a fuel dispenser, around vent risers extended by 1.5 m, within 1.5 m of a tanker offload point during delivery, and around generator exhaust manifolds). SBKJ specifies 304 stainless ductwork for any duct passing through Zone 0 or Zone 1; galvanised mild steel is acceptable in Zone 2 only where continuous earthing is verified at commissioning.
AS 1940 — Storage and handling of flammable and combustible liquids
AS 1940 covers petrol, diesel, ethanol blends (E10, E85, E100), AdBlue and other flammable liquids. It governs setbacks, bunding, vent riser heights, tank fills and forecourt layout. For HVAC, AS 1940 establishes the geometric envelopes that AS/NZS 60079.10.1 classifies as hazardous zones, and specifies a 3 m setback minimum between any vent riser and any building opening — a hard requirement that HVAC outdoor-air intake placement must respect. The fuel oil truck offloading area is transient Zone 1 within 1.5 m of any tanker connection during delivery; HVAC intakes closer than 6 m must be capable of BMS-interlocked shutdown during delivery.
AS 1596, AS 4564, AS 5601, AS 4332 — LPG and gas storage
AS 1596 covers LPG storage. For convenience-store BBQ-cylinder swap cages, AS 1596 requires mechanical ventilation at a minimum 6 air changes per hour, ducted from low level (LPG vapour is heavier than air), with the exhaust discharge at least 3 m above ground and 3 m from any building opening. Duct material is stainless steel (304 minimum, 316 coastal), continuously bonded and earthed. AS 4564 covers general gas installation, AS 5601 covers gas pipework, AS 4332 covers specialty gases including welding shielding gas at workshop bays.
NFPA 30A and NFPA 30 — US references for motor fuel dispensing
NFPA 30A is the US code for motor fuel dispensing, referenced informally in Australian fuel retail engineering particularly for multinational operators (Tesla colocation, Costco, Caltex legacy). NFPA 30A treats a 4.6 m / 1.2 m envelope around a dispenser as Class I Division 2 (equivalent to Zone 2 under IEC/Australian classification). NFPA 30 covers broader flammable liquids; NFPA 88A covers parking structures (relevant for service plaza covered parking).
AS 1668.1 and AS 1668.2 — Mechanical ventilation in buildings
AS 1668.1 covers kitchen exhaust, smoke control, stair pressurisation and zone smoke control. For roadhouse and service plaza scope AS 1668.1 is the controlling kitchen code — hood capture velocity 0.4–0.5 m/s, galvanised duct for non-grease-laden and 304 stainless or black steel for grease-laden, slope back to hood at 1:50 minimum, cleanout doors at every direction change, discharge at least 3 m above any roof level and 3 m horizontal from any intake.
AS 1668.2 (2012) is the governing ventilation code for retail, public toilet and amenity scope. Rates are: convenience retail at 5 L/s per person at design occupant density; customer toilets at 25 L/s per WC and 25 L/s per urinal continuous extract (or 10 ACH whichever is greater); public showers at 30 L/s per head; staff rooms and offices at 10 L/s per person; food preparation at the AS 1668.1 kitchen rate; enclosed canopy at 12 ACH mechanical exhaust. For a 250 m² convenience store total fresh-air supply lands in 800–1,200 L/s; for a typical rest stop amenity block with four WCs, two urinals and one accessible shower the exhaust runs to 175 L/s minimum.
AS 4254.1 and AS 4254.2 — Ductwork for air-handling systems
AS 4254.2 is the Australian rectangular-duct construction standard, harmonised with SMACNA in many respects. It specifies sheet-metal gauge by duct dimension and pressure class, reinforcement spacing, joint type (TDF, Pittsburgh seam, snap-lock), and sealant class (A, B, C). Most roadside retail ductwork is specified to Class B leakage with 250 Pa pressure rating. AS 4254.1 covers flexible duct, limited to 1.5 m maximum length per connection and prohibited in concealed plenums.
AS 1428.1 and AS 1428.2 — Disability access
AS 1428.1 (2009) and AS 1428.2 (1992) specify the dimensional requirements for accessible toilet cubicles, ambulant cubicles, accessible showers and circulation space. Ceiling-mounted exhaust grilles and supply diffusers must not encroach on the minimum 2,250 mm vertical clearance over the cubicle, access doors for cleaning must be positioned outside the cubicle envelope, exhaust grilles must be located directly over the WC pan (not over the basin) to capture odour at source, and the 950 mm minimum outward door swing must not be obstructed. The Disability Discrimination Act 1992 (DDA) is the federal legal basis; the National Construction Code (NCC) Volume One Part D3 references AS 1428.1 as the prescriptive compliance pathway. Non-compliance triggers both NCC and potential DDA action — LGAs and main roads agencies are particularly sensitive to this exposure.
AS 1742, AS 3000, AS/NZS 5139, NFPA 855, AS 1530.4, AS 1851, FSANZ, AS 4326, Privacy Act 1988, ACMA
AS 1742 covers traffic signage and pavement marking (relevant for kerb cut and EV charging signage). AS/NZS 3000 (Wiring Rules) governs fan motor termination, BMS panel earthing, hazardous-area conduit and emergency shutdown logic. AS/NZS 5139:2019 covers battery storage up to 200 kWh; NFPA 855 and IEC 62933 govern utility-scale and forecourt-colocated BESS. AS 1530.4 covers fire resistance testing of fire dampers; AS 1851 covers routine service every 12 months. FSANZ 3.2.2 (food safety) and 3.2.3 (food premises) apply to every roadhouse kitchen, convenience hot food display and coffee counter; AS 4326 covers HACCP cold chain. The Privacy Act 1988 (Cth) and ACMA telecommunications standards apply to modern fuel dispensers, EV chargers and BMS-linked HVAC controllers connected to operator IT networks.
Section 3 — Public toilet and amenity block HVAC: the most demanding small-footprint scope
A public toilet looks small. Its HVAC scope is anything but. The block must operate 24/7 unmanned, resist vandalism, deliver continuous ventilation to AS 1668.2, meet the AS 1428.1 accessibility envelope with no compromise to clearance or door swing, accommodate a parents’ room with baby change, in some cases meet cultural appropriateness consultation for indigenous community design, and survive corrosive sea-air, alpine cold-air or red-dust outback environments without maintenance call-outs for the first ten years of asset life. SBKJ has supplied galvanised G275 and 304 stainless duct for public amenity block programmes across more than half the Australian LGA territories and a significant share of the national parks and state main roads rest stop scope.
The duct route inside a typical amenity block
For a 60–120 m² block: outdoor air supply is drawn from a high-level intake on the windward face, ducted through a small AHU or in-line fan, distributed to a low-level supply diffuser in the male, female, accessible and ambulant cubicle vestibules. Exhaust is taken from a high-level grille located directly over each WC pan and urinal stall, ducted to a low-noise centrifugal extract fan in the ceiling void or on the roof, and discharged through a weatherproofed roof terminal at least 3 m horizontal from the intake. The accessible shower stall has its own 30 L/s exhaust and a moisture-resistant diffuser supply. The parents’ room with baby change has a 30 L/s exhaust over the change table.
Duct material is galvanised G275 for inland and most metro and rural locations, switching to 304 stainless or aluminised steel for coastal sites within 5 km of salt-air atmosphere on the East Coast, South Coast NSW, Surf Coast Victoria, and the entire coastal perimeter of WA, Queensland, NT and Tasmania. The SBAL-V automatic duct line fabricates both galvanised and 304 stainless rectangular sections in the same machine envelope; the SBFB-1500 spiral tubeformer produces round duct from 80 mm to 1,500 mm diameter for the exhaust riser.
AS 1428.1 accessibility envelope constraints
Accessible cubicle minimum dimensions are 1,900 mm wide and 2,300 mm deep, WC centreline 450–460 mm from the side wall and 700–750 mm from the rear wall, side-wall grab rail at 800–810 mm AFL, 950 mm minimum outward door swing, 1,500 mm wheelchair turning circle, 2,250 mm minimum vertical clearance. The ceiling-mounted exhaust grille is positioned over the WC pan at minimum 2,400 mm AFL clear of the grab rail; the supply diffuser sits in the vestibule outside the wheelchair turning circle. The ambulant cubicle is 900 mm wide and 1,600 mm deep, grab rails on both side walls, exhaust at the back wall or directly above WC. The accessible shower stall is 1,160 mm by 1,160 mm minimum with folding seat and handheld hose; the exhaust grille is positioned at the ceiling outside the shower spray zone.
Cultural appropriateness, coastal spec and vandalism resistance
Where a block serves a community with significant indigenous representation — remote NT, WA and Far North Queensland communities, plus Coober Pedy, Lake Mungo, Uluru-Kata Tjuta, Kakadu, eastern Pilbara — cultural appropriateness consultation may dictate separation between male and female sections beyond the standard 1.5 m partition, separate access points with physically separate duct routes, and adjustments to cubicle layout, mirrors and grab rails. SBKJ recommends engagement with the relevant Indigenous Land Use Agreement (ILUA) holder or Local Aboriginal Land Council (LALC) at the design stage; the HVAC contractor takes a position behind this consultation rather than driving it.
Coastal blocks (Bondi, Burleigh Heads, Cottesloe, Surfers Paradise) switch to 304 stainless duct on exhaust and aluminised mild steel on supply. SB-ZF1500 stitchwelder runs the longitudinal seam on 304 stainless drum sections; SBLR-600 handles custom stainless fittings. Vandalism design responses: stainless steel grilles bolted from above, tamper-evident screws, recessed light fittings, smashproof cubicle locks with external override, and oversized ductwork allowing a single grille blockage without compromising extract rate. Continuous 24/7 fan duty (rather than occupancy-based switching) raises parasitic energy consumption but eliminates the failure mode where vandalism to the occupancy sensor leaves the amenity unventilated.
Section 4 — Service station forecourt: Zone 1 vapour recovery and the benzene problem
Walk onto an Australian service station forecourt and the immediate impression is open air, steel canopy, painted bollards, clean pavement. The HVAC engineering reality is a layered envelope of hazardous-area classification within which the wrong choice of duct material, fan motor or earthing strap is a documented ignition source. The Workplace Exposure Standard for benzene — the most demanding inhalation hazard — is 1 ppm short-term exposure limit and 1 ppm 8-hour TWA. Australian unleaded petrol contains 1–3 percent benzene by volume. Toluene WES is 50 ppm, xylene 50 ppm, ethylbenzene 100 ppm, naphtha 100 ppm, n-hexane 50 ppm, n-pentane 600 ppm. The HVAC ductwork specification must support a vapour recovery system that captures dispensed vapour at source and returns it to the underground tank ullage without leakage.
Vapour recovery Stage I and Stage II
Stage I vapour recovery captures vapour displaced from the underground storage tank during tanker delivery and returns it to the tanker through a 75–100 mm flexible hose — sealed system, no direct HVAC duct involvement. The HVAC scope is surrounding tanker offload bay ventilation, transient Zone 1 within 1.5 m of the connection during delivery, reverting to Zone 2 between deliveries. SBKJ specifies a 12 ACH offload bay extract with IECEx Ex-d ATEX motor mounted at least 4.5 m clear of the tanker connection, 304 stainless duct bonded and earthed.
Stage II captures vapour displaced from the vehicle tank during refuelling via a coaxial hose internal to the dispenser (Gilbarco, Wayne Dresser, Tatsuno OEM-supplied). The forecourt-wide HVAC contribution is canopy ventilation — open-sided canopies rely on natural cross-ventilation; enclosed or three-sided canopies require mechanical exhaust at 12 ACH minimum with 304 stainless duct, bonded and earthed, IECEx Ex-d ATEX fans. The SB-ZF1500 stitchwelder is the production tool for the stainless seams. Stage II is mandated in some Australian states (notably Victoria) and not in others — confirm with the local EPA before specifying.
Underground tank vent stack and LPG cylinder swap cage
The UST breather vent stack discharges at least 4 m above ground and 3 m horizontally from any building opening (AS 1940). The Zone 1 envelope extends 1.5 m sphere around the discharge point. No air intake or exhaust grille within the Zone 1 envelope; any building close to the vent stack has its intake oriented away from the discharge.
LPG cylinder swap cages (BBQ refill swap) at convenience-store forecourts are Zone 1 throughout the cage interior. AS 1596 requires 6 ACH mechanical ventilation, ducted from low level (LPG vapour is heavier than air and pools at floor level), exhaust discharge at least 3 m above ground and 3 m from any building opening. SBKJ specifies 304 stainless duct, continuously bonded and earthed, IECEx Ex-d ATEX motor on a centrifugal fan mounted outside the cage envelope, 1.6 mm wall thickness minimum machine-formed on SBAL-V with Pittsburgh seam.
Ethanol blend, automotive LPG and hydrogen H2 forecourts
E10, E85 and E100 ethanol blend forecourts (at selected United, Liberty and 7-Eleven sites) have the same Zone 1 envelope as conventional petrol, with the added complication that ethanol vapour has a lower flash point and wider flammable range. SBKJ specifies the same 304 stainless and IECEx Ex-d ATEX scope, with aluminium fan impeller alloys (5052 or 6061) checked for ethanol compatibility. Automotive LPG (forklift cylinder swap, caravan refill) at United, Liberty, Puma and selected Ampol/BP sites is Zone 1 throughout the dispenser envelope; HVAC scope is canopy ventilation as above.
Hydrogen H2 refuelling at 350 bar (heavy vehicle) and 700 bar (passenger car) is in pilot scale at Coregas Yennora NSW, ATCO Jandakot WA, Fortescue Williamtown NSW and Toyota dealer demonstration sites. The Zone 1 envelope is 6 m horizontal and 3 m vertical from the nozzle — significantly wider than petrol. SBKJ specifies 304 stainless duct for all HRS vent and purge lines, IECEx Ex-d ATEX motors and spark-resistant aluminium impeller fans throughout, nitrogen purge connections before commissioning, continuous H2 leak detection at high level (hydrogen is lighter than air, opposite to petrol and LPG which sink), and HVAC shutdown logic on H2 detection above 25 percent of LEL (LEL is 4 percent in air for H2, so trigger is 1 percent H2 in air). The HRS dispenser, compressor and storage equipment is OEM-supplied (Nel ASA, McPhy, Plug Power, Linde Engineering, Air Products, Cummins HyDrive); HVAC contractor scope is canopy ventilation, control room HVAC, cooling tower exhaust and integration with leak detection and emergency shutdown logic.
Section 5 — Convenience store and forecourt retail HVAC
The convenience store is where the fuel retail operator earns most of its retail margin. The HVAC design has to keep customers comfortable, control humidity for refrigeration efficiency, and meet the AS 1668.2 fresh-air rate, all while minimising the duct footprint inside a tight ceiling void. The store is non-hazardous under AS/NZS 60079.10.1 provided entry doors are outside the Zone 2 envelope around forecourt dispensers — the 7.5 m horizontal setback is built into every modern forecourt site plan.
Internal set point is 22–24 °C summer and 20–22 °C winter, RH 40–60 percent, NC-40 acoustic target. AS 1668.2 outdoor air rate at 5 L/s per person at design occupant density (one person per 4 m²) yields 250 L/s for a 200 m² store. Customer toilets add 25 L/s per WC and 25 L/s per urinal; staff rooms add 10 L/s per person; food preparation adds the AS 1668.1 kitchen exhaust rate. Total fresh-air supply for a typical 250 m² store is 800–1,200 L/s.
Hot food display cabinets (pies, sausage rolls, hot dogs) and barista coffee stations are minor extract loads at 50–150 L/s per cabinet and 100–200 L/s for coffee — non-grease-laden hoods under AS 1668.1 with galvanised mild-steel duct and separate roof discharge. Where a forecourt store includes a full QSR tenancy (Hungry Jack’s, KFC, Subway, Oporto, Domino’s, Krispy Kreme, Guzman y Gomez, Zambrero, Boost Juice, Schnitz, Roll’d, Sushi Sushi, Chatime, Gong Cha, Mad Mex) the scope expands to a full AS 1668.1 / NFPA 96 kitchen exhaust with stainless internal lining on grease-laden runs, 1:50 minimum slope back to hood, cleanout doors at every direction change, and discharge at least 3 m above roof level and 3 m from any intake. See the SBKJ cafe and quick-service restaurant HVAC duct guide. OTR is the most aggressive convenience format because it routinely co-locates QSR tenancy plus Tesla Supercharger and EV fast charging.
The walk-in cool room (drinks, dairy, grab-and-go) is typically 8–15 m² at 2–4 °C with RH 80–90 percent — galvanised duct with closed-cell elastomeric insulation, vapour barrier intact, condensate drainage to a floor waste outside the cool room envelope. AS 4326 cold chain HACCP applies with temperature monitoring on the BMS. Walk-in freezers operate at −18 to −22 °C, typically reach-in cabinets. ATM enclosure is 18–28 °C internal. The forecourt office/POS/CCTV room has 24/7 thermal load from server equipment requiring a dedicated AC unit with UPS-backed emergency air supply.
Section 6 — EV charging hub HVAC: minor scope, major coordination
An EV charging hub has no fuel vapour, no hazardous-area classification under any DC charging canopy, no vapour recovery requirement and no underground storage tank. HVAC scope is limited to equipment cabinet thermal management (OEM-supplied), optional waiting-area shelter ventilation if enclosed, and any colocated BESS battery support cabinet. But coordination scope is significant: charger placement, canopy clearance, transformer location, BESS cabinet, driver lounge, food retail tenancy and fuel-forecourt colocation all influence duct layout.
A 50–350 kW DC fast charger dissipates 4–42 kW of waste heat at peak load (94–96 percent conversion efficiency). Tritium DCFC, ABB Terra HP, Kempower C-series, Schneider EVlink, Tesla Supercharger V3/V4 and Hitachi ABB Energy fast chargers integrate liquid cooling internal to the cabinet. The HVAC contributing scope is the equipment building where multiple cabinets are housed indoors (typical of Evie or Chargefox ultra-rapid hubs), at 50–100 L/s of forced ventilation per 50 kW installed charger capacity, galvanised mild-steel duct to AS/NZS 4254, separate insulated discharge stack.
Grid-constrained EV hubs increasingly colocate a BESS battery support cabinet (100 kWh to 2 MWh, supplied by Tesla Megapack, Sungrow PowerStack, Fluence Gridstack, Wartsila Quantum, Powin Stack, GE Vernova FlexInverter or Hyundai HD) for peak shaving. Cabinet HVAC is OEM-integrated with NFPA 855 explosion control. HVAC contractor scope is the surrounding building, with AS/NZS 5139 alignment for behind-the-meter systems up to 200 kWh and NFPA 855 reference for larger systems. See the SBKJ EV charging hub and BESS HVAC duct guide. Premium hub models (Tesla Supercharger V4, Chargefox ultra-rapid, Evie ultra-rapid) integrate driver lounges with AS 1668.2 retail rate at 5 L/s per person, galvanised duct, full AC at 22–24 °C and NC-40.
Section 7 — Highway rest stop, motorway service plaza and truck driver fatigue facility
Highway rest stops along Australian motorways — Pacific, Hume, Newell, Bruce, Western, Princes, Eyre, Stuart, Great Northern, Calder, Sturt, Mid Western, Olympic, Riverina — deliver the most distributed amenity-block infrastructure in the country. Transport for NSW operates 200+ rest stops, VicRoads 150+, Queensland TMR 200+, DIT SA 80+, MRWA 150+, with similar networks in Tasmania, NT and ACT adding another 100+. The driver reviver volunteer programme operates over 220 designated sites where free tea and coffee are offered during peak holiday periods.
The typical rest stop amenity block is 40–100 m² single-storey concrete or steel-framed with male, female, accessible and ambulant toilets, parents’ room with baby change, accessible shower, unmanned 24/7 operation, tank-fed potable water where reticulated water is unavailable. HVAC follows Section 3 public toilet design plus parents’ room exhaust at 30 L/s, accessible shower at 30 L/s, optional B-Triple driver shower at 30 L/s per head on certified driver fatigue sites. Duct material is galvanised G275 inland, 304 stainless or aluminised steel coastal.
NHVR-certified driver fatigue facilities require a sleeping pavilion, kitchen and dining area, hot-water shower facility, separate male/female amenity, B-Triple parking. HVAC scope expands to sleeping pavilion at 10 L/s per person, AS 1668.1 kitchen exhaust, laundry with dryer venting and combustion flue separation, and shower exhaust at 30 L/s per head. Motorway service plaza concessions on the Hume (Marulan, Pheasants Nest, Goulburn, Albury), Pacific (Tuggerah, Maitland, Coffs Harbour, Macksville, Ballina), Newell (Forbes, Coonabarabran, Moree), Bruce (Bald Hills, Glasshouse Mountains, Cooroy, Mackay) and Western (Bacchus Marsh, Ballarat, Horsham, Nhill, Bordertown) highways operate under concessions with HMSHost Australia, NewRest Australia, SSP Australia and independents. The scope combines retail, kitchen, fuel forecourt and accessible toilet plus a full QSR tenancy, food court with multiple QSR brands sharing back-of-house, convenience store, coffee tenancy, pharmacy or general retail, and integrated EV charging on newer sites.
Section 8 — Remote roadhouse HVAC: the Eyre and Stuart highway scope
A remote roadhouse on the Eyre or Stuart Highway is functionally a self-contained village delivering fuel, food, motel accommodation, laundry, shower and amenity services, often with single diesel-generator power and bore water supply. The HVAC scope expands accordingly: AS 1668.1 commercial kitchen exhaust, 12–30 room motel section, laundry handling combustion-appliance and dryer venting, beer garden or licensed bar with smoke management zone if enclosed, separate male/female public showers at 30 L/s per head, and underground fuel storage with full Zone 1 vapour recovery. The roadhouse must accommodate ambient temperatures regularly exceeding 45 °C in summer and 0 °C overnight on inland routes, driving evaporative cooling on the kitchen and refrigerative split systems on the motel with insulated supply ductwork.
Eyre and Stuart Highway roadhouses
The Eyre Highway between Norseman WA and Ceduna SA is the longest unbroken straight road in Australia — the 90 Mile Straight between Caiguna and Balladonia is 146.6 km. The 18 roadhouses across the 1,200 km route (Eucla, Mundrabilla, Madura, Cocklebiddy, Caiguna, Balladonia, Norseman, Nullarbor, Penong, Border Village, Yalata, Nundroo, Ceduna) are spaced 80–150 km apart and each is operationally critical. Duct material is galvanised G275 with 304 stainless on kitchen exhaust and forecourt vapour recovery.
The Stuart Highway between Port Augusta SA and Darwin NT traverses 2,720 km of outback through Coober Pedy, Marla, Kulgera, Erldunda, Stuarts Well, Alice Springs, Aileron, Ti Tree, Wycliffe Well, Wauchope, Renner Springs, Three Ways, Banka Banka, Newcastle Waters, Daly Waters, Larrimah, Mataranka, Katherine, Pine Creek, Adelaide River and Hayes Creek. HVAC scope adds extreme thermal environment (Coober Pedy summer regularly exceeds 45 °C), red-dust intrusion (Plenty Highway, Tanami Track, Outback Way), and limited maintenance availability. The Daly Waters Pub, Renner Springs Hotel, Banka Banka Station, Three Ways Roadhouse at the Stuart-Barkly junction, Mataranka Homestead, Borroloola Hotel, Curtin Springs Cattle Station (Lasseter Highway), and the heritage-listed Old Dunmarra Roadhouse all combine bar, kitchen, motel, laundry, public shower and amenity.
Diesel-generator primary power, carwash and vacuum bay
Remote roadhouses on the Eyre and Stuart highways operate primary diesel-generator power. HVAC plant must accept higher frequency drift (typically ±1 percent versus ±0.05 percent on grid) and voltage variability (±5 percent versus ±1 percent on grid). SBKJ recommends high-efficiency centrifugal fans with VSD drive, fan motor rated for harmonic distortion, and duct sizing margin (20 percent oversize on cross-section, 30 percent oversize on fan capacity). The generator room is Zone 2 around the exhaust manifold, requires 80–120 ACH forced ventilation during operation with combustion air intake separate from cooling air, and the diesel particulate filter exhaust routes at least 3 m above roof and 3 m from any building opening. SBKJ specifies aluminised mild steel duct for the generator exhaust path; SBSF-1525 handles plate cutting for hood and elbow fabrication, SBLR-600 runs custom stainless drum cut-outs.
Single-bay drive-through carwash or self-serve bay is common; HVAC scope is limited to worker amenity and the payment kiosk. Carwash chemical and wet process is OEM-supplied (Tammermatic, Istobal, Washtec, Karcher). Truck wash bays at roadhouses add wet ductwork and chemical sump exhaust. Vacuum and detailing bays have no HVAC scope.
Section 9 — Workplace Exposure Standards and forecourt worker safety
The forecourt worker exposure profile is the determining factor in the HVAC specification on a service station forecourt. The Workplace Exposure Standards (WES) published by Safe Work Australia cover every air contaminant the forecourt worker may inhale. The most demanding is benzene at 1 ppm 8-hour time-weighted average and 1 ppm short-term exposure limit (STEL). Australian unleaded petrol contains 1 to 3 percent benzene by volume, and the WES for benzene was tightened from 5 ppm to 1 ppm in 2018. Toluene WES is 50 ppm TWA, xylene 50 ppm TWA, ethylbenzene 100 ppm TWA, naphtha (petroleum solvent) 100 ppm TWA, n-hexane 50 ppm TWA, n-pentane 600 ppm TWA. Methyl tert-butyl ether (MTBE) is rarely used as an additive in Australian petrol and has a WES of 50 ppm TWA. Propane WES is 1,000 ppm, methane (LPG/CNG) 1,000 ppm asphyxiant. Oxygen must be maintained between 19.5 and 23.5 percent.
Carbon dioxide WES is 5,000 ppm TWA — relevant in an overcrowded rest stop or roadhouse where natural ventilation is insufficient. Carbon monoxide WES is 30 ppm TWA — relevant for vehicle exhaust accumulation under enclosed canopies and from gas appliance combustion in roadhouse kitchens and motel rooms. Nitrogen dioxide STEL is 5 ppm — relevant from vehicle exhaust. Refrigerant exposure (R32, R410A, R744 CO2) is handled separately under the refrigeration installation code. Formaldehyde STEL is 1 ppm — relevant in new-build amenity blocks with curing concrete and new MDF cabinetry. VOC general (cleaning chemical, air freshener) is handled with general dilution ventilation. Chlorine STEL is 0.5 ppm — relevant for toilet cleaning operations. Ozone WES is 0.1 ppm TWA — relevant for UV sterilisation systems in some public amenity blocks. Methane (CH4) lower explosive limit is 1.25 percent for some monitoring devices — relevant for LPG and CNG alternative fuel sites.
Benzene control hierarchy
The control hierarchy for benzene exposure on a service station forecourt is, in order of preference: elimination (not possible — benzene is intrinsic to Australian petrol), substitution (not currently available at commercial scale), engineering controls (vapour recovery Stage I and Stage II, mechanical canopy ventilation where required, no air intake within 6 m of a dispenser), administrative controls (worker rotation, shift duration limits, training, signage), and personal protective equipment (PPE — respirators are the last line of defence). The HVAC duct contractor sits squarely in the engineering controls layer. The duct schedule, the vapour recovery routing, the canopy ventilation design and the air intake placement are all part of the documented control measures that the operator presents to Safe Work Australia and the relevant state work health and safety regulator (SafeWork NSW, WorkSafe Victoria, Workplace Health and Safety Queensland, SafeWork SA, WorkSafe WA, WorkSafe Tasmania, NT WorkSafe, WorkSafe ACT) at site licensing and during periodic audit.
Section 10 — Operator-by-operator specification notes
Each major Australian operator carries its own head-office HVAC specification on top of the regulatory baseline. The duct contractor must read both layers before tendering.
Fuel retail majors
Ampol (ASX:ALD, ~1,900 sites): Foodary and Star Mart sites use galvanised mild steel to AS/NZS 4254 for retail, 304 stainless for any duct routed through or terminating in a hazardous zone, NC-40, 22 °C set point, AS 1668.1 kitchen exhaust, Ex-rated LPG cage exhaust, AmpCharge EV colocation on metro and highway sites.
BP Australia (~1,500 sites): Reddy Cafe sites use fully sealed Class C ductwork to AS 4254.2 with low-VOC sealant, AS 1668.1 kitchen hoods with stainless internal lining on grease-laden runs, BP Pulse EV fast charging at 150–350 kW colocated on metro sites.
Viva Energy Shell Coles Express (ASX:VEA, ~700 sites): Shell global retail standard plus Australian regulatory overlay, 23 °C, NC-40, galvanised supply with insulated returns. Enclosed-roof canopy variant on some sites requires mechanical extraction over the dispenser island, triggering Ex-rated duct and fan specification.
7-Eleven Australia (~720 sites): Galvanised mild steel to AS/NZS 4254, packaged rooftop unit feeding ceiling supply, low-level return through ceiling grilles, stainless internal toilet exhaust discharging above the canopy line.
United Petroleum (~500 sites): Higher proportion of refurbishment work with constrained ceiling voids. Higher share of E10, E85 and LPG forecourts than the majors.
Liberty Oil (~350 sites), Puma Energy (~350 sites): Higher diesel mix and workshop or service-bay components; mining and commercial customer presence in WA, NT and Queensland.
OTR On The Run (Peregrine, ~170 sites): Most demanding format. New-build sites run two independent rooftop AHUs (convenience store plus QSR tenancy), dedicated AS 1668.1 kitchen exhaust, and Tesla Supercharger or other EV charging colocation.
EV charging networks
Tesla Supercharger (100+ sites): OEM-supplied; HVAC contractor scope is the surrounding equipment building or canopy where Tesla’s site delivery contractor is engaged. Chargefox (400+ sites): driver lounge, equipment building, toilet block, optional retail, galvanised mild steel throughout. Evie Networks (100+ sites): St Baker Energy Group spec favours stainless detailing on visible duct termination. NRMA EV Fast Chargers (70+ sites): NSW/ACT member-benefit destinations, HVAC integrated with host facility. JOLT (80+ sites): kerbside model, no associated building HVAC. Ampol AmpCharge, BP Pulse: see fuel majors above.
Hydrogen and public infrastructure operators
Coregas Yennora NSW: 350 and 700 bar HRS, 304 stainless throughout purge envelope, IECEx Ex-d ATEX motors, nitrogen purge, continuous H2 leak detection at high level, HVAC shutdown logic on detection above 25 percent of LEL. ATCO Jandakot WA: coastal environment requires 316 stainless on exposed runs. Fortescue Williamtown NSW: colocated with electrolyser pilot. Toyota Mirai dealer demonstration sites (Altona, Sydney): smaller dispenser footprint.
Local government authority public toilet programmes: Largest LGAs (City of Sydney, City of Melbourne, City of Brisbane, City of Adelaide, City of Perth, Sunshine Coast, Gold Coast, Wollongong, Newcastle, Geelong) carry detailed in-house specifications. Smaller regional councils reference AS 1668.2 and AS 1428.1 minima with site-specific adjustments. State main roads authorities (Transport for NSW, VicRoads, Queensland TMR, DIT SA, MRWA, DSG Tasmania, DIPL NT) carry their own asset standards for highway rest stop amenity blocks.
Section 11 — SBKJ machine specification for the full roadside infrastructure scope
The SBKJ machine catalogue covers the complete fabrication scope for Australian roadside infrastructure HVAC.
SBAL-V automatic duct line — SBKJ’s flagship automatic rectangular duct line, fabricating galvanised G90, 304 stainless and aluminised steel up to 1.5 mm thickness in the same machine envelope. Produces TDF or Pittsburgh-seam joints, accepts coil stock up to 1,500 mm width. Covers public toilet and amenity galvanised duct, convenience store retail, EV equipment building, roadhouse motel section, plus 304 stainless rectangular runs for vapour recovery, LPG cage, hydrogen refuelling purge and commercial kitchen grease-laden exhaust. See the SBKJ SBAL-V product page.
SBSF-1525 servo plasma cutter — plate cutting up to 1,500 mm by 2,500 mm for hood fabrication, elbow throat cutting, end-cap, kitchen hood plate, vapour recovery hood and hydrogen purge enclosure plate.
SBFB-1500 spiral tubeformer — round duct from 80 mm to 1,500 mm diameter in galvanised G90 and 304 stainless. Used for waiting areas, retail showrooms, kitchen exhaust risers, toilet exhaust risers, vapour recovery riser stacks, hydrogen purge risers. Spiral duct’s helical seam is widely accepted as a design feature in modern convenience store fitouts.
SB-ZF1500 stitchwelder — production tool for 304 stainless seams on vapour recovery, hydrogen purge, LPG cage and commercial kitchen grease-laden exhaust. Continuous fillet weld with controlled heat-affected zone and smooth interior surface for cleaning and inspection.
SBPC1500 plasma cutter — smaller-footprint table for fitting plate, joint plate, TDF tabs, Pittsburgh seam reinforcement angle, fire damper and access door cut-outs.
SBLR-600 longitudinal seam welder — high-spec stainless drum cut-outs for custom tee, wye, elbow and transition fittings on vapour recovery, hydrogen purge, LPG cage and grease-laden kitchen exhaust.
Machine selection by scope: a metro service station with convenience store, EV charging and accessible toilet uses SBAL-V (90 percent of rectangular fabrication), SBFB-1500 (exhaust risers and visible round duct), and SB-ZF1500 (vapour recovery and LPG cage seams). A remote roadhouse adds SBSF-1525 (kitchen hood), SBPC1500 (fitting plate) and SBLR-600 (custom stainless fittings). A hydrogen refuelling station is dominated by SB-ZF1500 and SBLR-600 because every duct is 304 stainless. See the SBKJ full machine list.
Section 12 — Worked example: a Hume Highway combined service centre
Take a hypothetical 4,500 m² combined service centre at a Hume Highway interchange between Sydney and Melbourne. The site combines a 12-pump petrol/diesel forecourt with LPG cylinder swap cage, 200 m² convenience store with barista coffee and hot food display, 150 m² QSR tenancy (Hungry Jack’s), 8-stall Tesla Supercharger V4, 6-stall Chargefox ultra-rapid, covered driver lounge, accessible public toilet block, truck driver fatigue facility with showers and sleeping pavilion, and a small workshop. The site operates 24/7 with full convenience and forecourt staffing 6 am to midnight.
Hazardous zone mapping and HVAC rates
Hazardous zone mapping identifies twelve separate envelopes: six Zone 1 around each fuel dispenser (4.5 m horizontal, 1.2 m vertical), one Zone 1 inside the LPG cage, one transient Zone 1 at the tanker offload point during delivery, two Zone 2 around the underground tank vent risers, one Zone 2 around the generator exhaust manifold, plus Zone 2 envelopes extending from the Zone 1 boundaries out to 7.5 m. The Tesla Supercharger, Chargefox, convenience store, QSR, accessible toilet, driver lounge and truck driver fatigue facility are all non-hazardous provided AS 1940 minimum setbacks are met (6 m clear of any dispenser, 3 m clear of any vent riser).
Total HVAC outdoor air: convenience store at 5 L/s per person for 60 people = 300 L/s, plus 25 L/s per WC and per urinal for 2 WCs and 1 urinal = 75 L/s, plus 30 L/s shower = 30 L/s, plus AS 1668.1 kitchen exhaust at 0.5 m/s face velocity across a 3 m by 0.6 m QSR hood = 900 L/s, plus hot food display 100 L/s and barista coffee 150 L/s, plus accessible toilet block 4 WCs and 2 urinals = 150 L/s, plus truck driver fatigue 4 showers = 120 L/s plus 4 WCs = 100 L/s, plus LPG cage at 6 ACH for 5 m³ = 30 L/s. Total approximately 2,000 L/s supply and 1,500 L/s exhaust.
Duct schedule and SBKJ machine load
Duct schedule: approximately 280 lineal metres of rectangular duct (180 m galvanised G275 across convenience, QSR, EV equipment building and motel; 100 m 304 stainless across QSR kitchen, vapour recovery, LPG cage and coastal-spec accessible toilet). 120 lineal metres of round duct (80 m galvanised across convenience and EV waiting area exhaust risers; 40 m 304 stainless across tank vent risers and kitchen risers). 38 fire dampers. 4 IECEx Ex-d ATEX motors on LPG cage, vapour recovery extract and two enclosed-canopy extract fans. 12 access doors at every direction change of the kitchen exhaust. Total duct fabrication labour approximately 320 machine-hours.
SBKJ machine load: SBAL-V approximately 220 lineal metres of rectangular fabrication (galvanised and stainless), SBFB-1500 approximately 120 lineal metres of round duct, SB-ZF1500 approximately 40 lineal metres of stainless seam, SBSF-1525 approximately 80 hood and elbow plate cut-outs, SBPC1500 approximately 120 fitting tab cut-outs, SBLR-600 approximately 20 custom stainless drum sections. The full load fits within a single SBKJ Australian fabrication shop production cycle.
Section 13 — Procurement, commissioning and maintenance
Procurement of HVAC ductwork for an Australian roadside infrastructure project follows a four-stage sequence: design, fabrication, installation, commissioning. The integrated duct schedule lists every run by zone (toilet, retail, kitchen, forecourt, LPG, hydrogen, EV, motel, generator), material (galvanised G275, 304 stainless, 316 stainless coastal, aluminised, black mild steel for kitchen), gauge (0.55–1.6 mm depending on dimension and pressure class), joint type (TDF, Pittsburgh seam, slip-coupling, stitchwelded longitudinal seam), insulation, sealant class (A, B or C to AS 4254.2), IECEx certification number where applicable, and bonding/earthing requirement for any duct in or crossing a hazardous zone.
Factory Acceptance Test and installation
Every SBKJ-fabricated duct package is subject to FAT before site delivery: dimensional check against drawing tolerances (typically ±2 mm rectangular, ±1.5 mm round), seam integrity (visual and tactile inspection), pressure test where specified (leakage to AS 4254.2 Class B or C), and a documentation pack with material test certificate, gauge, seam type, FAT sign-off and Certificate of Origin. The FAT pack forms part of the operator’s commissioning documentation and is required by every Tier-1 Australian operator. Installation sequence is civil works first, then mechanical rough-in, then electrical, then fit-out, then commissioning — with main spine runs delivered first and diffuser drops, branch lines and final connections delivered as fit-out approaches completion. Coordination with the fire engineer, BMS contractor, kitchen tenant and OEM equipment suppliers (Tritium DCFC, Tesla Supercharger, Coregas Hydrogen) is critical.
Commissioning and ongoing maintenance
Commissioning follows the AS 1668.2 air balance protocol with measured flow rates at every supply diffuser and exhaust grille, validated against the design schedule and adjusted by damper position to match design intent within ±10 percent. For hazardous-area scope, commissioning includes a final check of IECEx Ex-d ATEX equipment certification, duct bonding and earthing measurements, and leak detection and HVAC shutdown logic on hydrogen and LPG sites. See the SBKJ HVAC commissioning and air balancing guide.
Asset life expectation is 15–25 years for the duct, 5–10 years for fan motor and BMS controls. AS 1851 covers annual fire damper testing, periodic fan motor service, duct cleaning (every 5–7 years for retail and kitchen, every 3 years for grease-laden kitchen, every 2–3 years for hazardous-area duct in vapour recovery and LPG cage scope), and kitchen hood cleaning (every 3 months for high-volume QSR). Forecourt vapour recovery, hydrogen refuelling and LPG cage maintenance follow written hot-work permit procedures with the system isolated, purged and ventilated before any intrusive work; IECEx motor certification is verified annually, duct bonding and earthing measured annually, and the H2 leak detection sensor calibrated quarterly. Roadhouse kitchen grease-laden exhaust is cleaned every 3–6 months depending on volume, with the duct interior steam-cleaned annually and the fire suppression system serviced under AS 1851.
Section 14 — Future direction and conclusion
The Australian roadside infrastructure market is on a clear trajectory toward multi-energy combined sites — a single forecourt offering petrol, diesel, LPG, EV fast charging, hydrogen refuelling, BESS battery support and a full convenience and food retail programme under one canopy. Ampol Foodary EV and BP Pulse colocation are early examples; OTR with Tesla Supercharger and full QSR tenancy is more advanced. The Coregas Yennora hydrogen demonstration and the Fortescue Williamtown hydrogen pilot point toward a future where hydrogen refuelling becomes a standard adjacent service. Capex per square metre on a multi-energy site is significantly higher than a single-fuel site — an Ampol Foodary EV site at AU$8–12 million versus a traditional Ampol site at AU$3–5 million, and an OTR-style multi-energy combined site approaching AU$15–20 million. The HVAC duct contractor’s share is in the 1–3 percent range — AU$150,000–AU$450,000 on a AU$15 million site — a meaningful share of any contractor’s annual revenue.
Three near-term drivers will shape HVAC duct demand. EV charging hub densification is moving from sub-50 kW destination chargers to ultra-rapid 350 kW hubs along all major highway corridors, each adding an equipment building, driver lounge, public toilet and colocated retail tenancy. Hydrogen refuelling expansion supported by ARENA, the CEFC and the National Hydrogen Strategy 2024 update will scale particularly along heavy-vehicle freight corridors as Hyzon Motors and H2X commercial vehicle programmes need refuelling infrastructure to operate. BESS battery support cabinet integration on grid-constrained EV charging hubs is already widespread and will scale further as more highway hubs come online in grid-weak regional and outback locations.
Roadside infrastructure is the densest small footprint in the Australian HVAC market. A 1,500 m² combined service centre stacks more regulatory complexity, more material specifications, more hazardous-area envelopes and more operator interfaces than a 20,000 m² CBD office tower. The HVAC duct contractor who masters the AS 1668.2, AS/NZS 60079, AS 1940, AS 1596, AS 1428.1, AS/NZS 5139, AS 1668.1 and AS 4254 regulatory stack — and who can deliver fabrication on time, on specification and with a complete FAT documentation pack — will win repeat work across Ampol, BP, Viva Energy, 7-Eleven, United, Liberty, Puma, OTR, Tesla, Chargefox, Evie, NRMA, JOLT, BP Pulse, Coregas Hydrogen, ATCO, Fortescue, BIG4, Discovery Parks, the state main roads agencies and the LGA public toilet programmes for the next decade.
SBKJ Group’s scope on this market is HVAC duct fabrication machinery — SBAL-V automatic duct line, SBSF-1525 plasma cutter, SBFB-1500 spiral tubeformer, SB-ZF1500 stitchwelder, SBPC1500 plasma cutter, SBLR-600 longitudinal seam welder — supported by engineering consultation, FAT documentation and field service from the SBKJ Australian engineering office in Box Hill North, Victoria. ARBS 2026 at the International Convention Centre Sydney from May 19–21, 2026 is the next concentrated meeting point — SBKJ exhibits as Stand 236 under the Australia Ducting Pty Ltd entity with the full machine catalogue on demonstration.
Get an SBKJ duct machine quote for Australian roadside infrastructure work →
FAQ
What ventilation rate does an Australian public toilet require under AS 1668.2?
AS 1668.2 (2012) requires continuous mechanical extract at 25 L/s per WC pan and 25 L/s per urinal stall, with a separate 30 L/s extract per shower head where showers are present. For a typical highway rest stop amenity block with four WC pans, two urinals and one accessible shower, total exhaust runs to 175 L/s minimum, sized up to 220–250 L/s in practice to handle peak loading.
Why is a service station forecourt classified as Zone 1 hazardous area?
AS/NZS 60079.10.1 classifies the envelope within 4.5 m horizontal and 1.2 m vertical of any fuel dispenser, vent stack, tank fill or breather as Zone 1 because petrol vapour is present under normal operating conditions during refuelling. Australian petrol contains 1–3 percent benzene, with a Workplace Exposure Standard short-term exposure limit of 1 ppm.
How does AS 1428.1 DDA accessibility affect public toilet HVAC duct design?
Ceiling-mounted exhaust grilles, supply diffusers and ducted services must not encroach on the minimum 2,250 mm vertical clearance over the cubicle, the 950 mm minimum cubicle door swing, or the 1,500 mm wheelchair turning circle. Exhaust extraction is taken from a high-level grille located directly over the WC pan, not over the basin, to capture odour at source.
What HVAC scope sits inside the canopy of an EV charging hub versus a petrol forecourt?
An EV charging canopy has no fuel vapour, no Zone 1 hazardous classification and no vapour recovery requirement. The HVAC scope is limited to equipment cabinet thermal management (OEM-supplied), optional waiting-area ventilation if enclosed, and any colocated BESS battery support cabinet. A petrol forecourt has Zone 1 around every dispenser, Zone 2 around the canopy envelope, a Zone 0 underground tank, vapour recovery Stage I and Stage II ductwork, an LPG cylinder swap cage at Zone 1, and a generator exhaust path classified Zone 2.
What ductwork material is required for hydrogen refuelling station HVAC?
Hydrogen vapour has an ignition energy roughly an order of magnitude lower than petrol vapour, a flammable range from 4–75 percent in air, and a Zone 1 envelope around 350 bar and 700 bar dispensers of 6 m horizontal and 3 m vertical from the nozzle. SBKJ specifies 304 stainless steel duct for all hydrogen refuelling station vent and purge lines, IECEx Ex-d ATEX motors and spark-resistant fans throughout.
How does a remote roadhouse on the Eyre or Stuart Highway differ from a metro service station HVAC design?
A remote roadhouse is functionally a self-contained village with full commercial kitchen, motel section, laundry, public showers, beer garden, fuel forecourt and amenity block. Primary diesel-generator power introduces higher frequency drift and voltage variability, requiring oversized duct cross-section and higher specification fan motors. Ambient temperature regularly exceeds 45 °C in summer and 0 °C overnight on inland routes.
Which SBKJ machines fabricate ductwork for the full roadside infrastructure scope?
SBAL-V auto duct line for galvanised and 304 stainless rectangular fabrication, SBSF-1525 plasma cutter for hood and elbow plate, SBFB-1500 spiral tubeformer for round duct, SB-ZF1500 stitchwelder for stainless seams on hazardous-area scope, SBPC1500 plasma cutter for fitting plate, SBLR-600 longitudinal seam welder for custom stainless fittings. Every machine is built and supported from the SBKJ Australian engineering office in Box Hill North, Victoria.
