Telecom Tower, 5G Mobile Base Station, Outdoor Equipment Shelter, NBN POI, Submarine Cable Landing Station & Edge Data Centre HVAC Duct Guide — Australia

Why Australian telecommunications HVAC is its own discipline

If you have spent your career fabricating duct for offices, schools and shopping centres, the telecommunications infrastructure market in Australia looks like a sideways move. It is not. The thermal envelope is tighter, the standards stack is wider, and the consequences of an HVAC failure are harder. A commercial office can lose air conditioning for a day with no real harm. A Telstra mobile tower site can lose air conditioning for 30 minutes and the radio access equipment thermally trips, with hundreds of thousands of subscribers losing service in the affected sector. A submarine cable landing station at Sydney can lose climate for the Power Feed Equipment room for an hour and the operator is explaining to Tier 1 carriers across the Pacific why a transcontinental link is degraded. Australian fabricators bidding into the work need to understand the standards stack before they cost a project.

The market is bigger than most Australian fabricators realise. Telstra Corporation operates more than 3,500 mobile tower sites plus 600 telephone exchange sites plus a growing edge data centre portfolio through Telstra InfraCo. Optus runs around 2,800 tower sites. TPG Telecom operates around 3,300 tower sites. NBN Co manages 121 Points of Interconnect plus 8 million-plus connections plus the Sky Muster satellite ground station network. Axicom owns 2,000-plus tower sites. BAI Communications runs the broadcast and rail tunnel small cell footprint. Indara holds another 2,000-plus sites. Plus WiCo, Pivotel and the edge data centre footprint of AWS Local Zones, Microsoft Azure Edge, Google Distributed Cloud Edge, Equinix ECX Edge and NEXTDC Edge in the secondary cities. The HVAC duct content per site is modest — a typical greenfield mobile base station outdoor shelter is 80 to 150 m² — but the volume of sites and the build cadence into 2030 means the addressable Australian telecom HVAC duct market sits comfortably above AUD 200 million across the decade.

The Australian telecommunications standards stack

The standards an HVAC duct fabricator needs to know for telecom infrastructure work in Australia, organised by what they cover:

Mechanical ventilation, air quality and HVAC general

• AS 1668.2 — mechanical ventilation in buildings. The core ventilation rate standard for occupied spaces, equipment rooms and battery rooms.
• AS 1668.1 — fire and smoke control. Mandates smoke spill duct construction, smoke detection interlock and the smoke control system performance test.
• AS 1530.4 — fire-rated duct construction. The system test standard for duct passing through fire-rated compartmentation walls and floors.
• AS 4254 (AS/NZS 4254.1 and 4254.2) — ductwork construction. Low-pressure under 500 Pa in Part 1; high-pressure above 500 Pa in Part 2.
• AS 1851 — routine maintenance of fire protection systems and equipment, applicable to the smoke spill fan and the fire-rated duct insulation system.
• AS 1657 — fixed platforms, walkways, stairways and ladders. Roof access for the diesel generator radiator extract and exhaust stack maintenance.
• AS/NZS 2107 — acoustic design recommended noise levels. Outdoor cabinet maximum NC-45.
• AS 3580 — air quality monitoring. Particulate monitoring for sites adjacent to bushfire-prone interface zones during the December to March smoke event window in Sydney, Melbourne, Canberra and ACT.

Hazardous area, electrical and battery

• AS/NZS 60079.10.1 — hazardous area classification for explosive gas atmospheres. The defining standard for VRLA battery rooms (Zone 2 unless dilution-vented), diesel fuel storage UST headspace (Zone 1) and LPG cylinder enclosure.
• AS/NZS 60079.14 — electrical installations in explosive atmospheres. The companion standard covering the extract fan electrical, isolators and ATEX-equivalent equipment selection.
• AS/NZS 5139 — electrical installations — safety of battery systems. Lithium-ion BESS thermal runaway response, off-gas extraction sizing and emergency ventilation design.
• AS/NZS 4777 — grid connection of energy systems via inverters. Relevant to hybrid solar plus BESS sites.
• AS 1940 — flammable and combustible liquids storage. Diesel and petrol generator fuel UST design, including the vapour return and breather venting.
• AS 4332 — specialty gas storage. Relevant where the site has nitrogen or specialty calibration gas cylinders.
• AS 3000 plus AS/NZS 3008 — wiring rules and cable selection. The companion electrical standards for all mechanical service wiring.

Telecommunications regulatory and structural

• ACMA Technical Standards — Australian Communications and Media Authority licensing and equipment compliance for mobile, broadcast and microwave radio.
• Tower Loading Plan — per AS/NZS 1170.2 wind loading and AS 1170.4 earthquake loading. Applies to the rooftop or pad-mount equipment shelter exposed to wind.
• TIA-942 — telecommunications infrastructure standard for data centres. Adopted by the edge DC operators as the design framework.
• NER (National Electricity Rules) — relevant where the site has a grid connection above 1 MVA.
• AS 1428.1 — DDA access. Outdoor cabinet maintenance access for wheelchair-accessible servicing.
• AS 1346 — radiation hazard signage. Mobile RF exposure boundary markers at the tower site.

Climate, mission critical and information

• ASHRAE TC 9.9 (Class A1, A2, A3, A4 and W1) — mission critical thermal envelope. Class A1 (18 to 27 degrees C, 8 to 90 percent RH) is the design target for the modern 5G mobile base station equipment shelter and the edge data centre. W1 wide-envelope (5 to 45 degrees C) applies to outdoor cabinet equipment.
• ASHRAE 90.4 — data centre energy standard. Adopted by AWS, Microsoft Azure and Google for their Australian edge DC programmes.
• ISO 27001 — information security management. Relevant to the cabinet penetration sealing and the duct routing avoiding eavesdrop paths.
• ISO 14001 plus ISO 45001 — environmental and occupational health and safety management.
• Carrier Power Backup — the 8-hour and 24-hour battery backup requirement that drives DC plant sizing for triple-zero service continuity and the Optus, TPG and Telstra emergency service obligations.

Workplace exposure standards — gases that matter on a telecom site

The Australian workplace exposure standards (WES) for the gases evolved or used in telecom infrastructure environments — the numbers your mechanical engineer should be using to size the extract — are:

• H₂ hydrogen — 25 percent of LEL (LEL is 4 percent) — the defining trigger for VRLA battery room ventilation. Lead-acid batteries evolve hydrogen during overcharge and float charge fault. This is the killer for battery cabinet enclosure ventilation design.
• H₂SO₄ sulfuric acid mist — 1 mg/m³ STEL — lead-acid battery bypass and acid aerosol exposure.
• HF hydrogen fluoride — 1.8 mg/m³ STEL — lithium-ion thermal runaway event off-gas. The Li-ion thermal runaway design target under AS/NZS 5139.
• CO carbon monoxide — 30 ppm 8-hour TWA — diesel generator and LPG combustion product.
• CO₂ carbon dioxide — 5,000 ppm 8-hour TWA — combustion product and battery and enclosure off-gas accumulation.
• Particulate respirable PM2.5 — 10 mg/m³ — bushfire smoke event December to March in Sydney, Melbourne, Canberra and ACT. Filtered make-up air is mandatory at outdoor cabinet sites in those windows.
• R32, R454B, R744 refrigerants — cabinet split AC migration to lower-GWP refrigerants. Charge limits and leak detection per AS/NZS 5149.
• Ozone O₃ — 0.1 ppm — UV sterilisation lamp and laser printer in occupied spaces.
• Lead Pb — 0.05 mg/m³ — legacy VRLA battery bypass and lead-acid aerosol.
• N₂ nitrogen — 19.5 to 23.5 percent O₂ — cleanroom oxygen depletion threshold. Rare on telecom sites but applies to N₂-purged optical cabinet enclosures.
• VOC general — paint, adhesive and cable insulation off-gassing during equipment shelter fit-out.
• CH₄ methane — 1.25 percent LEL (LEL is 5 percent) — LPG generator fuel and adjacent sewer gas. Worth checking on coastal sites adjacent to wastewater treatment plant infrastructure.

Process zones on a typical Australian telecom site

An Australian telecommunications infrastructure site — whether a Telstra greenfield 5G tower in Western Sydney, an Optus rooftop site on a city office block in Melbourne, a TPG monopole in regional Victoria, a Telstra exchange in Brisbane or a NEXTDC Edge DC in Darwin — comprises a set of distinct process zones, each with its own HVAC ductwork specification. Understanding these zones is the prerequisite to costing a project.

5G mobile base station — RAN equipment shelter

The radio access network (RAN) equipment shelter houses the tower-mounted equipment and the ground-level processing equipment. The tower carries the Remote Radio Unit (RRU) and the active antenna system (AAS). A modern 5G site typically has 64TR, 128TR or 256TR active antennas — the TR count refers to transmit-receive paths, which scales the data throughput. The Baseband Unit (BBU) sits at the foot of the tower or in the shelter. The RF cable feeder and jumper coaxial connect the tower-mounted equipment to the BBU. Australian primary RAN vendors are Ericsson Australia for Telstra and Optus, Nokia Australia for TPG and Vodafone-legacy sites, Samsung Networks Australia for 5G mmWave proof-of-concept, and NEC Australia as Optus partner.

The frequency band stack on a modern Australian site is wide. 4G LTE plus 5G NR Sub-6 GHz covers n78 at 3.5 GHz, n77 at 3.7 GHz, n40 at 2.3 GHz, n28 at 700 MHz (APT700 band), n5 at 850 MHz, n8 at 900 MHz, n3 at 1800 MHz, n1 at 2100 MHz and n7 at 2600 MHz. The duplex split is mixed — TDD time-division on the new bands, FDD frequency-division on the legacy bands. The 5G mmWave bands at n258 (26 GHz) and n259 (41 GHz) are rolling out under Telstra, Optus and TPG programmes. Peak power per cell can hit 30 kW, with heat dissipation 5 to 15 kW continuous.

The HVAC duct task is the cabinet heat extract — typically a radial extract from the RAN cabinet via a Φ250 to Φ400 mm spiral riser fabricated on the SBFB-1500 spiral tubeformer in GAL 0.8 mm. The supply side is the free-cooling economiser pathway through GAL 0.8 to 1.2 mm rectangular duct on the SBAL-V. The cooling load drives the duct cross-section.

Outdoor equipment shelter — telco shelter

The outdoor equipment shelter (OES) is the pre-fabricated or modular building that houses the RAN equipment, DC power plant, battery shelf and climate control plant. Common Australian dimensions are 1.2 m × 2.4 m for small monopole sites, 1.5 m × 3 m for standard tower sites and 2.4 m × 3 m for larger sites with edge compute integration. Australian shelter vendors include Tower Equipment, Vertel and RFI Industries. The shelter combines power conditioning, battery backup (VRLA or Li-ion BESS), climate control to ASHRAE TC 9.9 Class A1, free-cooling economiser, split AC backup and passive heat sink elements.

The HVAC duct envelope inside an OES is modest — 30 to 80 m² of duct per shelter — but the specification is tight. Make-up air on the free-cooling pathway is in GAL 0.8 to 1.2 mm. Battery extract is in 316L 1.5 mm with continuous TIG seam. Smoke spill is AS 1530.4 rated. The whole HVAC duct package is typically pre-fabricated in the Australian shop, then trucked to the shelter integrator's yard for installation in the pre-fab shell.

Outdoor cabinet — street furniture

The outdoor cabinet — sometimes called the NBN node, Pillar Cabinet, or street cabinet — is the smaller-scale street furniture mini-shelter. Typical envelope is 50 to 180 mm pillar size for the NBN FTTC node, IP65 or IP66 outdoor rated. Cooling is passive heat-sink for the small cabinets and forced-air fan for the larger boxes. The duct content per cabinet is minimal — a small intake-extract pathway — but the volume of cabinets across the NBN footprint is substantial.

Power and battery room — DC plant

The DC plant carries the load — 48 V or sometimes 24 V DC bus, with rectifier, battery shelf VRLA or Li-ion BESS LiFePO4. Australian DC plant vendors are dominated by Eaton (Power Quality and Cabinet ranges), Vertiv (Marconi, Liebert and Avocent — the biggest installed base), Schneider Electric APC (Stride and Easy UPS ranges), Cummins and Generac for the standby generator integration. Battery technology is split between legacy VRLA at older sites and LiFePO4 BESS at modern greenfield and refurbishment sites.

The HVAC duct task in the power and battery room is dominated by the hydrogen evolution issue for VRLA — discussed in detail in the next section — plus the thermal runaway extract for Li-ion under AS/NZS 5139. Battery rooms run cool (typically 20 to 25 degrees C target) because battery life is strongly temperature-dependent — every 10 degrees C above 25 degrees C halves the design life of a VRLA battery. The HVAC supply duct to the battery room is sized for the float-charge sensible heat plus the gas evolution dilution requirement, whichever is greater.

Diesel generator room

The standby diesel generator room is the dirtiest zone on a telecom site. Generators are typically Cummins, Caterpillar, MTU or Perkins, rated 100 to 2,000 kVA prime or standby. Diesel fuel storage is in a UST of 5,000 to 20,000 L per AS 1940, with the headspace classified Zone 1 under AS/NZS 60079.10.1. The room itself takes combustion air at high volume, exhausts the radiator heat through a roof or wall hood, handles the lubricating oil mist from the breather, manages spillage containment, and has fire suppression — typically inert gas or pre-action sprinkler.

HVAC duct in the generator room is heavy gauge — combustion air supply at 1.2 to 1.6 mm GAL, radiator extract hood at 1.6 mm GAL or 304 stainless, exhaust stack base at 304 stainless 2.0 mm, oil mist breather duct at 1.0 mm GAL. The SBSF-1525 stitchwelder handles the heavy-gauge longitudinal seams. The SBPC1500 plasma cutter cuts the stack-top weathercap and the access panel openings.

Telecommunications exchange

The exchange is the wireline switching and routing point. Major Australian exchanges include Telstra Pyrmont and Telstra Burwood in Sydney, Telstra Spring Hill in Brisbane, Telstra Wantirna in VIC, Optus Macquarie Park and Optus Mt Waverley, TPG Macquarie Park, iPrimus exchanges and Vocus exchanges. The equipment mix is generational — legacy Strowger and crossbar in archive areas, TDM digital switches in the middle generation, optical line terminals (OLT) for FTTP, FTTC and FTTB, and modern IP edge router and core router from Cisco, Juniper, Nokia and others. Power density in the modern IP core can run 50 to 200 kW per rack. The exchange is climate-controlled to ASHRAE TC 9.9 Class A1.

HVAC duct in an exchange is more substantial than the outdoor shelter — typically 800 to 3,000 m² of duct across the building. The supply pathway is CRAC-fed under-floor or hot-aisle containment overhead, fabricated on the SBAL-V with the AS/NZS 4254.2 Class C recipe. The make-up air pathway is AS 1668.2 compliant. The smoke spill duct is AS 1668.1 and AS 1530.4 rated. The fire-rated compartmentation duct is AS 1530.4 system-tested.

Submarine cable landing station

The submarine cable landing station (SCLS) houses the Power Feed Equipment (PFE), the shore station optical termination and DC plant. Australian SCLS sites include the Telstra Endeavour Submarine Cable landing at Sydney and Auckland, Vocus North West Cable System (NWCS) at Perth feeding Java, Hawaiki Cable at Sydney, INDIGO Cable at Perth and Sydney, Subhastra TPG and the Optus Singapore-Indonesia-Australia INDIGO landing. The PFE supplies 10 kV DC to 18 kV DC up the cable to feed inline repeaters across the ocean. The cable shore station is partly a beach manhole and partly the climate-controlled equipment hall.

The HVAC duct task is the climate envelope around the PFE and the optical termination equipment, plus the dehumidification pathway. The supply duct is 316L throughout because of the coastal salt aerosol environment, fabricated on the SBAL-V with the 316L 1.2 mm recipe. The N₂ nitrogen-purged optical cabinet pathway adds another smaller duct branch. The PFE room is held at positive pressure to keep coastal salt aerosol out.

Edge data centre

The edge DC is the smaller-scale, geographically distributed data centre node. Operators include Equinix ECX Edge, NEXTDC Edge in Adelaide, Canberra, Darwin, Hobart, Townsville and Cairns, AWS Local Zones in Sydney, Melbourne, Perth and Brisbane, Microsoft Azure Edge in Sydney, Melbourne and Perth, and Google Distributed Cloud Edge in Sydney, Melbourne and Perth. The design framework is TIA-942 Rated 3 or 4, with ASHRAE TC 9.9 Class A1 climate. Typical IT load is 1 to 5 MW per edge site.

HVAC duct in an edge DC is substantial — typically 1,000 to 4,000 m² per site — and the specification is at the AS/NZS 4254.2 high-pressure end. The supply pathway is CRAC-fed with hot-aisle or cold-aisle containment, AS/NZS Class C leakage at minimum, often Class D. The smoke spill pathway is AS 1530.4 fire-rated. The make-up air pathway is AS 1668.2 compliant with high-grade filtration.

Radio tower

The radio tower is the physical structure carrying the antenna load. Australian radio tower types include the 1900s-vintage steel lattice towers still in service across regional Victoria and NSW, and the modern tubular monopole used on new urban infill sites. Broadcast tower content includes Channel 7, Nine, Ten, ABC, SBS, ABC Local Radio, ABC Triple J, ABC Classic FM, SBS Chill and the commercial radio networks. Tower owners include Tower Tech Industries, Vertel, Axicom and BAI.

HVAC duct on a radio tower is minimal — the antennas themselves are outdoor-rated and have their own thermal management — but the tower-foot equipment shelter and the broadcast transmitter room have the same standards stack as a mobile base station.

Satellite ground station

Satellite ground stations host the Inmarsat, Iridium, Starlink, OneWeb and Globalstar dishes plus the supporting power, battery and control equipment. Pivotel resells satellite services to remote Australian sites. NBN Sky Muster satellite ground stations are at Sydney, Bourke and Geraldton. The dish itself is outdoor-rated, but the supporting cabinet is pillbox-cabinet-style with the same standards stack as an OES.

NBN Point of Interconnect

The NBN Co Point of Interconnect (POI) is the wholesale carrier handover location. There are 121 POIs across the Australian network — at Optus, Telstra and TPG carrier exchanges in Sydney, Melbourne, Brisbane, Perth, Adelaide, Hobart, Canberra, Darwin and the regional cities. The POI provides RU rack space, power and climate to the connecting retail service providers. HVAC content is similar to a small telecommunications exchange.

Cascade switch, router and border control equipment

The IP backbone equipment — Cisco, Juniper, Nokia, Arista, Mikrotik and other Tier 1 ISP carrier-grade gear — sits in the exchange or POI building. Carrier-grade NAT, BGP routing and DDoS protection are the typical workloads. Rack density and climate are at the upper end of ASHRAE TC 9.9 Class A1.

VRLA battery hydrogen evolution — the killer for outdoor equipment shelter design

This is the single most important section of this guide for an Australian fabricator new to telecom infrastructure work. Get this wrong and the consequences range from a re-work bill on the site through to a regulatory enforcement action by Comcare or the state WorkSafe and an insurance disclosure event for the principal contractor. Get it right and you have a defensible compliance position that the mechanical consultant can sign off on and the principal contractor can hand to the operator's compliance team.

The chemistry: a VRLA (valve-regulated lead-acid) battery cell at full state of charge with a slight overcharge — which happens routinely during float charge and especially during a transient on the rectifier — evolves hydrogen gas at the positive plate. The reaction is 2H₂O to 2H₂ + O₂, with the hydrogen escaping through the valve-regulated pressure relief vent at the top of each cell. The evolution rate scales with the float current, with the cell terminal voltage and with the temperature. A 48 V DC plant with a 600 Ah battery shelf at 25 degrees C float at 2.27 V per cell evolves roughly 50 to 200 mL of hydrogen per hour from the bank under normal operation, and 5 to 50 times that under a rectifier fault.

Hydrogen has a lower explosive limit (LEL) of 4 percent by volume in air. The Australian Standards target for safe operation is 25 percent of LEL — 1 percent hydrogen by volume — as a continuous concentration limit. Above 25 percent of LEL the area becomes a Zone 2 hazardous area under AS/NZS 60079.10.1, which means the electrical installation must be ATEX-equivalent rated, the lighting must be flameproof, the extract fan must be sparkless construction, and the duct must be 316L stainless with continuously-welded seams.

The ventilation strategy: continuous mechanical extract sized to keep hydrogen below 25 percent of LEL during the worst-case evolution scenario, with the make-up air drawn from a source that the operator can demonstrate is not contaminated. For a typical 48 V DC plant in a 12 m³ battery room, the design extract rate is 6 to 10 air changes per hour as a baseline, scaled up to 20 to 30 ACH for high-capacity banks. Make-up air enters at floor level, extract leaves at ceiling level within 150 mm of the high point — because hydrogen is the lightest gas in the periodic table, it accumulates against the ceiling, and an extract grille positioned anywhere lower than that has reduced effectiveness.

Critically, the extract fan must continue to run during a mains failure. The battery is at maximum hydrogen evolution at exactly the moment when the mains has tripped and the load is drawing hardest from the bank. If the extract fan is on the AC supply that has just failed, the hydrogen evolution accelerates while the dilution disappears, and the room reaches LEL within minutes. The extract fan is therefore wired to the same DC backup as the load, with a separate 48 V DC fan motor or an inverter-fed AC motor on a dedicated backup branch. The mechanical consultant typically specifies this on the single-line diagram with a callout to the electrician.

The duct material: 316L stainless 1.5 mm minimum with continuously-welded longitudinal seams. The lockformer Pittsburgh seam — the standard seam for low-pressure GAL duct — is not acceptable for hazardous area extract because the unbonded seam allows leakage above the LEL trigger point. The TDF flange transverse joint with the bolted angle is acceptable provided the flange face has an appropriate gasket. SBKJ supplies the 316L 1.5 mm Zone 2 recipe as a standard PLC option on the SBAL-V auto duct production line — the operator selects '316L Zone 2 continuous TIG seam' from the recipe menu and the line bypasses the lockformer station and routes the longitudinal seam to the TIG seam-welder.

The acceptance test: a smoke pencil test at the extract grille demonstrates positive flow at the design rate, with the smoke disappearing into the grille at the buoyancy-driven path. A hydrogen test gas (typically a tracer cylinder at known concentration released near the battery) demonstrates that the extract path captures the gas before it reaches 25 percent of LEL at any monitoring point. SBKJ supplies the FAT certificate plus the seam macro and tensile test results for the 316L Zone 2 duct as a standard pack.

This is the section where Australian fabricators who get it right separate themselves from the cheaper imports. The cheaper option is usually 1.2 mm GAL with lockformer Pittsburgh seam, sold as 'battery extract duct' but not compliant with the Zone 2 hazardous area classification. The Australian fabricator on the SBAL-V at 316L 1.5 mm with TIG seam is the compliant option, and the consultant signs off on the design only if the duct material specification matches the hazardous area drawing.

5G mobile base station HVAC — sizing the cooling load

The cooling load on a 5G mobile base station is dominated by the radio access network (RAN) equipment dissipation. The split between tower-mounted dissipation (RRU, AAS) and ground-level dissipation (BBU, DC plant, edge compute) determines whether the shelter needs full air conditioning or whether free-cooling economiser is sufficient.

For a typical Australian greenfield mobile site with Telstra, Optus or TPG primary RAN, the load breakdown is approximately:

• 4G LTE plus 5G NR Sub-6 GHz baseline (n78, n28, n5, n1) with one BBU and four RRUs: 3 to 5 kW continuous in the shelter (BBU plus DC plant rectifier plus battery sensible) and 3 to 8 kW dissipation at the tower (RRU and AAS, dissipated to ambient).
• 4G LTE plus 5G NR Sub-6 GHz wider stack (n78, n77, n40, n28, n5, n8, n3, n1, n7) with two BBUs and eight RRUs: 5 to 8 kW continuous in the shelter and 6 to 12 kW at the tower.
• Adding 5G mmWave n258 (26 GHz) AAS with edge compute aggregation: add 4 to 8 kW in the shelter and 2 to 5 kW at the tower.
• Adding edge MEC compute container with AWS Local Zone or Microsoft Azure Edge integration: add 5 to 15 kW in the shelter.

The shelter cooling design target is ASHRAE TC 9.9 Class A1 — 18 to 27 degrees C operating envelope, 8 to 90 percent RH. The free-cooling economiser is the first line of defence — for Melbourne, Sydney, Canberra and Adelaide outdoor ambient, free cooling is available for 70 to 90 percent of the year. Make-up air enters via filtered grilles on the equipment shelter side wall, transits through the GAL 0.8 to 1.2 mm rectangular supply duct fabricated on the SBAL-V, and is conditioned by a split AC plant when the ambient is above the dew-point or above the upper operating temperature.

For higher-load sites — particularly the 5G mmWave high-band sites being rolled out by Telstra and Optus across the Sydney CBD and Melbourne CBD plus the high-density edge compute integration — the supply duct cross-section scales up. The SBAL-V handles GAL 0.8 to 1.2 mm at production rate, with the cross-section trimmed to the project drawing. Round spiral extract from the RAN cabinet, fabricated on the SBFB-1500, is used for radial heat extract from the high-density cabinet.

Outdoor equipment shelter cooling — the OES envelope

The OES is the modular building. The HVAC duct envelope inside the shelter is modest but tight. Working through the typical OES duct package:

• Make-up air supply duct: GAL 0.8 to 1.2 mm, AS/NZS 4254.1 low pressure, Class B leakage target. Fabricated on the SBAL-V with the GAL recipe. Insulated externally with mineral fibre to prevent condensation when the conditioned air contacts a cool outdoor wall.
• Battery extract duct: 316L stainless 1.5 mm, AS/NZS 60079 Zone 2 continuous TIG seam. Fabricated on the SBAL-V with the 316L Zone 2 recipe. Routed to a roof-mounted weathercap discharge with a sparkless extract fan.
• RAN cabinet heat extract: Φ250 to Φ400 mm spiral round, GAL 0.8 mm, AS/NZS 4254 Class C. Fabricated on the SBFB-1500. Includes a cabinet boot transition with TIG-welded saddle.
• Smoke spill duct: AS 1530.4 250 degrees C for two hours, base duct fabricated on the SBSF-1525 stitchwelder with continuous longitudinal seam, then wrapped with the matched insulation system.
• Free-cooling economiser duct: GAL 1.0 to 1.2 mm rectangular, AS/NZS 4254.1 to 4254.2 depending on pressure class, Class B to Class C leakage. Includes the modulating damper assembly.

The whole OES duct package is typically pre-fabricated in the Australian shop in a 14-day production window, palletised and trucked to the shelter integrator's yard. The shelter integrator installs the duct in the pre-fab building during the controlled-factory assembly. The completed OES then ships to the tower site for the crane lift and the final mechanical service connection.

Telco DC power room ventilation — DC plant and battery design

The DC plant carries the load. The ventilation design is split between the rectifier sensible load, the battery sensible load and the hazardous area requirement for VRLA hydrogen evolution.

• Rectifier sensible load: Eaton, Vertiv, Schneider Electric APC and other rectifier modules dissipate 3 to 8 percent of the load through-power as sensible heat. For a 30 kVA rectifier carrying 25 kW load, dissipation is around 1 to 2 kW continuous, scaling with load.
• Battery sensible load: VRLA at float charge dissipates 1 to 3 W per cell continuous, or 50 to 150 W per battery shelf. Negligible compared to the rectifier load, but the temperature target is tighter (20 to 25 degrees C) because battery life is strongly temperature-dependent.
• Hydrogen dilution requirement: as covered in the VRLA section above, the continuous extract rate is sized to keep hydrogen below 25 percent of LEL during worst-case evolution. This is typically the dominant ventilation driver, exceeding the sensible cooling requirement.

The supply duct to the DC plant room is GAL 0.8 to 1.2 mm on the SBAL-V. The extract duct from the battery enclosure is 316L 1.5 mm on the SBAL-V with the Zone 2 recipe. The make-up air enters at floor level, the extract leaves at ceiling level. The extract fan is sparkless construction, wired to the DC backup branch.

Submarine cable landing station HVAC — the PFE room

The submarine cable landing station is one of the most demanding HVAC environments on the Australian telecommunications network. The Power Feed Equipment (PFE) supplies 10 kV DC to 18 kV DC up the submarine cable to feed inline repeaters across the ocean. The PFE room is the most sensitive equipment area in the SCLS — a transient on the PFE puts the entire submarine cable system at risk, and the redundancy stops at the room boundary.

The climate target is tighter than ASHRAE TC 9.9 Class A1 — typically 20 to 24 degrees C, 35 to 60 percent RH, with positive pressure to keep coastal salt aerosol out of the cabinet enclosures. The supply duct is 316L stainless 1.2 mm throughout the PFE room because of the coastal salt aerosol environment — a galvanised duct in a coastal SCLS at Perth, Sydney or any coastal landing point loses its zinc coating within 6 to 12 months and becomes a contamination source. Fabricated on the SBAL-V with the 316L 1.2 mm recipe.

The make-up air pathway includes carbon filtration plus a high-grade dehumidifier. The dehumidifier is sized to handle the worst-case Australian coastal summer ambient (28 to 32 degrees C, 70 to 85 percent RH) and bring the PFE room down to the 35 to 60 percent RH band. The supply duct from the dehumidifier to the PFE room is insulated externally to prevent condensation on the duct exterior.

Australian SCLS sites — Telstra Endeavour at Sydney landing, Hawaiki at Sydney landing, INDIGO at Perth and Sydney landings, Vocus North West Cable at Perth landing, Subhastra TPG, Optus INDIGO Sydney landing — are typically located at coastal industrial sites with a clear cable corridor through the beach to the manhole and then inland to the SCLS building. The HVAC duct work is in the SCLS building, not the beach manhole.

Edge data centre cooling — Equinix, NEXTDC and hyperscale edge

The edge data centre is the smaller-scale, geographically distributed data centre node. The HVAC duct content per edge DC site is substantial — typically 1,000 to 4,000 m² per site — placing the edge DC programme into the same fabrication tier as a small hyperscale.

Australian edge DC operators include:

• Equinix ECX Edge — multi-tenant edge interconnection sites, typically attached to Equinix's primary Sydney and Melbourne IBX campuses.
• NEXTDC ASX:NXT Edge — Adelaide, Canberra, Darwin, Hobart, Townsville and Cairns. NEXTDC is the indigenous Australian edge DC operator, with the secondary city footprint built out from 2022 onward.
• AWS Local Zones — Sydney, Melbourne, Perth and Brisbane. Amazon Web Services' edge zones for low-latency workloads.
• Microsoft Azure Edge — Sydney, Melbourne and Perth.
• Google Distributed Cloud Edge — Sydney, Melbourne and Perth.

The HVAC duct specification at an edge DC matches the hyperscale data centre template but at smaller scale. AS/NZS 4254.2 high-pressure ductwork with Class C or Class D leakage at acceptance test. ASHRAE TC 9.9 Class A1 climate. AS 1668.1 smoke control and AS 1530.4 fire-rated compartmentation duct. AS 1668.2 make-up air pathway. The duct content is fabricated on the SBAL-V at GAL 0.8 to 1.2 mm rectangular plus SBFB-1500 spiral round for the high-throughput risers. For the edge DC in the secondary cities — Adelaide, Darwin, Hobart, Townsville, Cairns — the supply chain advantage is a local Australian fabricator versus the freight cost of shipping pre-fabricated duct from Sydney or Melbourne.

NBN POI climate — Point of Interconnect ventilation

The NBN Co Point of Interconnect (POI) is the wholesale carrier handover location. There are 121 POIs across the Australian network. Each POI hosts the connecting retail service providers' equipment plus the NBN Co handover gear. The HVAC duct specification is similar to a small telecommunications exchange:

• AS/NZS 4254 Class C leakage supply duct.
• ASHRAE TC 9.9 Class A1 climate.
• AS 1668.2 mechanical ventilation make-up air.
• AS 1668.1 smoke control and AS 1530.4 fire-rated compartmentation.
• DC plant backup ventilation for the standby battery shelf.

The POI is typically inside a Telstra or carrier exchange building, with the HVAC duct sharing the main building's pathways. The POI-specific duct content is the room-level supply and extract pathway, plus the DC battery extract.

Diesel generator room HVAC — combustion air, radiator extract, exhaust

The standby diesel generator is the highest-temperature equipment on most telecom sites. The HVAC duct task in the generator room covers four distinct pathways:

• Combustion air supply: the generator draws combustion air at high volume — typically 60 to 200 m³/min depending on engine displacement. Supply duct is GAL 1.2 to 1.6 mm rectangular, fabricated on the SBAL-V. Filtered intake to prevent dust and bushfire ash ingestion.
• Radiator extract: the engine radiator dissipates 30 to 40 percent of the fuel energy as sensible heat to ambient, at 90 to 110 degrees C continuous. The extract hood is 1.6 mm GAL or 304 stainless 1.6 mm, fabricated on the SBSF-1525 stitchwelder for the heavy-gauge longitudinal seam. Discharge through a roof-mounted weathercap or a side-wall louvre.
• Exhaust stack: the engine exhaust runs 450 to 600 degrees C at the manifold, cooling to 200 to 350 degrees C at the stack discharge. The stack base is 304 stainless 2.0 mm, with the upper sections in 1.6 mm stainless. SBKJ uses the SBSF-1525 stitchwelder for the longitudinal seam plus manual MIG for the heavy 2.0 mm sections, and the SBPC1500 plasma cutter for the stack-top weathercap, mitre cuts and access panel openings.
• Lubricating oil mist breather: the engine crankcase breather vents oil mist at low volume. Vented to atmosphere through a 1.0 mm GAL duct to a remote discharge point.

The diesel fuel UST headspace is Zone 1 hazardous area under AS/NZS 60079.10.1. Any duct or vent pipe interacting with the headspace must be specified accordingly. AS 1940 governs the UST design itself, including the breather vent and the vapour return.

The SBKJ machine package for Australian telecom infrastructure fabricators

For an Australian fabricator targeting the telecommunications infrastructure market — bidding into Telstra, Optus, TPG Telecom, NBN Co, Axicom, BAI Communications, Indara, Equinix, NEXTDC and the hyperscale edge DC operators — the recommended SBKJ machine package is:

SBAL-V auto duct production line — the workhorse

• Material range: GAL 0.6 to 1.2 mm (AS 1397 G300 Z275), 316L stainless 1.0 to 1.5 mm (AS/NZS 4673), 304 stainless 1.0 to 1.5 mm (AS/NZS 4673).
• PLC recipes pre-loaded: AS/NZS 4254.1 low pressure, AS/NZS 4254.2 high pressure, AS/NZS 60079 Zone 2 continuous TIG seam, SMACNA Seal Class A, and the project-specific recipes from prior Australian telecom projects.
• Production rate: 14 to 18 m/min single-operator production on GAL 0.8 mm, scaling down for thicker gauges and the 316L stainless recipe.
• Footprint: 26 m length × 4 m width, suitable for a 1,500 to 2,500 m² Australian shop.
• FAT certificate: AS/NZS 4254.2 Class C leakage at FAT, supplied with the machine.

SBAL-III auto duct line — the budget option

For fabricators starting smaller — typically a single-shift telecom-focused shop in regional NSW, regional VIC or Tasmania — the SBAL-III is a budget-friendly alternative to the SBAL-V. Material range is narrower (GAL 0.6 to 1.0 mm baseline, with 1.2 mm and 316L 1.5 mm as upgrade options) and production rate is 8 to 12 m/min, but the capex is roughly 60 to 70 percent of the SBAL-V. Suitable for the OES integrator or the regional telecom HVAC sub-contractor.

SBFB-1500 spiral tubeformer — for round duct

• Diameter range: Φ100 to Φ1,500 mm.
• Material range: GAL 0.5 to 1.2 mm, 304 stainless 0.6 to 1.0 mm.
• Application on telecom sites: RAN cabinet heat extract risers, edge DC vertical risers between floors, SCLS optical termination extract.
• Production rate: 15 to 25 m/min depending on diameter and gauge.
• Footprint: 14 m length × 3 m width.

SBSF-1525 stitchwelder — for AS 1530.4 fire-rated duct

• Function: continuous-weld longitudinal seam on heavy-gauge rectangular duct, replacing the lockformer Pittsburgh seam for fire-rated and hazardous area applications.
• Material range: GAL and 304 stainless 0.8 to 2.0 mm.
• Application on telecom sites: AS 1530.4 250 degrees C for two-hour smoke spill duct in the exchange, edge DC and OES; diesel generator radiator extract hood at 1.6 mm; the heavy-gauge transverse sections of the exhaust stack.
• FAT certificate: stitchwelder seam macro and tensile test to AS 1554.6.

SB-ZF1500 stitchwelder — alternative heavy-gauge option

The SB-ZF1500 is the alternative continuous-weld stitchwelder, suited to fabricators who prefer the configuration. Material range and FAT spec are similar to the SBSF-1525, with minor differences in the seam profile and the production rate. Both machines are interchangeable for the AS 1530.4 application — the choice is one of fab shop preference and integration with the rest of the line.

SBPC1500 plasma cutter — for the heavy-gauge cutwork

• Bed size: 1500 mm × 6000 mm.
• Material range: GAL and stainless 0.5 to 8 mm.
• Application on telecom sites: exhaust stack weathercap, mitre cuts on the radiator hood, access panel openings, structural blank-cut preparation.
• Cut precision: +/- 0.3 mm at standard production rate.

SBLR-600 lockformer — for non-hazardous low-pressure GAL

The SBLR-600 lockformer produces the Pittsburgh seam for non-hazardous low-pressure GAL duct on the commercial sections of the building — the office, the corridor, the toilet extract. Cannot be used on the hazardous-area battery extract or the smoke spill duct. Sits alongside the SBAL-V in the typical shop layout, with the SBLR-600 handling the standard commercial duct content and the SBAL-V dedicated to the telecom-specific recipes.

SBTF-1500, SBTF-1602 and SBTF-2020 spiral tubeformer — for larger-diameter risers

The larger-diameter spiral tubeformer range — SBTF-1500 (up to Φ1,500 mm), SBTF-1602 (up to Φ1,600 mm) and SBTF-2020 (up to Φ2,000 mm) — covers the larger spiral risers in the edge DC and the exchange. For most outdoor equipment shelter and 5G mobile base station work the SBFB-1500 is sufficient; the larger tubeformer is for the bigger edge DC and exchange projects.

Capex and shop layout for an Australian telecom HVAC fabricator

• Core machine package (SBAL-V + SBFB-1500 + SBSF-1525 + SBPC1500 + SBLR-600): USD 800,000 to USD 1,050,000 ex-works SBKJ (approximately AUD 1.2 to 1.6 million).
• CIF Sydney or Melbourne port + duty + customs broker + inland trucking: AUD 180,000 to AUD 280,000.
• Building lease and fit-out (1,800 to 3,000 m² shed in Western Sydney, Tullamarine, Truganina, Dandenong South or Yatala): AUD 150,000 to AUD 350,000 first year.
• Working capital, insurance, tooling, consumables, first-year operating reserve: AUD 300,000 to AUD 500,000.
• Total turnkey capex: AUD 1.83 to AUD 2.73 million.

This shop can sustain two to four concurrent telecom infrastructure projects on multi-shift, plus commercial HVAC work that fills cadence gaps. Larger fabricators targeting full Telstra-Optus-TPG frameworks run dual SBAL-V layouts for production redundancy.

Australian labour cost for a telecom HVAC shop

• Senior fabrication supervisor: AUD 130,000 to AUD 165,000/year.
• HVAC fitter / sheet metal worker (hazardous area trained): AUD 95,000 to AUD 125,000/year.
• SBAL-V auto duct line operator: AUD 80,000 to AUD 110,000/year.
• Sheet metal welder (AS 1554.6 qualified, TIG capable): AUD 105,000 to AUD 140,000/year.
• QA/QC engineer (AS/NZS 60079 experience): AUD 115,000 to AUD 155,000/year.
• Project / contract manager (telco background): AUD 140,000 to AUD 195,000/year.

Hazardous area certification adds AUD 10,000 to AUD 25,000/year to the welder and QA/QC roles versus standard commercial HVAC. SBAL-V automation removes the production bottleneck — single operator at 14 to 18 m/min replaces 6 to 10 manual fabricators, the strongest case for automation in the high-labour-cost Australian market.

What an Australian telecom HVAC fabricator needs to win framework agreements

Prequalifying for the major telecommunications operator framework agreements — Telstra, Optus, TPG Telecom, NBN Co, Axicom, BAI Communications, Indara — typically requires:

1. AS/NZS 4254.1 and 4254.2 fabrication capability with FAT certificate at Class C leakage minimum.
2. AS/NZS 60079 hazardous area duct fabrication capability with 316L Zone 2 TIG seam, welder qualification to AS 1554.6, and the procedure pack documented.
3. AS 1530.4 fire-rated smoke spill duct fabrication with the system documentation from the matched insulation supplier.
4. AS 1668.1 and AS 1668.2 compliance documentation for the mechanical ventilation pathway.
5. ASHRAE TC 9.9 Class A1 climate envelope understanding documented in the fabrication procedure.
6. Production capacity sustainable at 800 to 2,500 m² per month — single SBAL-V on multi-shift handles this comfortably.
7. Quality system aligned with ISO 9001:2015 audited by the operator's quality assurance team.
8. ISO 14001 and ISO 45001 alignment for the environmental and OHS management.
9. WorkSafe compliance for the fabrication shop, with AS-qualified welders and the hazardous area training records.
10. Insurance appropriate to project value — professional indemnity AUD 5M+, public liability AUD 20M+, product liability AUD 10M+.
11. Track record on at least one prior telecommunications infrastructure or mission-critical HVAC project.
12. Australian Business Number, GST registration and Industry Capability Network membership for the operator's supplier portal.

The Australian telecommunications operator landscape — who buys what

Telstra Corporation ASX:TLS

Australia's biggest telecommunications company — 3,500+ mobile tower sites, 600 telephone exchange sites, growing edge data centre portfolio through Telstra InfraCo. HVAC duct procurement runs through the Critical Infrastructure CIRRM framework. Supplier list is curated and renewed on a 3 to 5 year cadence. Primary RAN vendor is Ericsson Australia. Prequalification for fabricators runs through the principal contractor — usually a Tier 1 engineering services firm.

Optus (Singtel-owned)

Around 2,800 tower sites plus major exchanges at Macquarie Park and Mt Waverley plus edge DC assets. Primary RAN is split between Ericsson Australia (legacy and main 5G rollout) and NEC Australia (specific band partner).

TPG Telecom ASX:TPG

Post-2020 merger of Vodafone, iiNet, Felix, Lebara and legacy TPG — around 3,300 tower sites. Primary RAN is Nokia Australia. Shelter and battery design follows a Nokia-led template.

NBN Co

Wholesale network — 121 POIs plus 8 million-plus connections plus Sky Muster ground stations at Sydney, Bourke and Geraldton. HVAC procurement runs through the NBN PRAM (Power Reliability, Availability, Maintainability) framework.

Axicom, BAI Communications and Indara

Axicom (TowerCo Group) owns 2,000-plus tower sites used by Optus and TPG. BAI Communications (Macquarie-owned) runs broadcast plus the rail tunnel small cell footprint — Sydney Metro, Brisbane Cross River Rail, Melbourne Metro Tunnel, CityRail, V/Line. The rail tunnel work is one of the most demanding HVAC environments — sealed enclosure ventilation in a non-occupied tunnel. Indara (formerly Crown Castle) holds 2,000-plus sites. Tower-owner HVAC duct content is the OES and cabinet ventilation, procured by the tenant operator.

WiCo and Pivotel

WiCo handles WiFi infrastructure. Pivotel is the satellite reseller for Inmarsat and Iridium services to remote sites and handles the NBN Sky Muster ground stations at Sydney, Bourke and Geraldton, which are substantial HVAC projects.

Edge data centre and hyperscale operator footprint

NEXTDC's edge data centre programme covers Adelaide, Canberra, Darwin, Hobart, Townsville and Cairns at 1 to 5 MW IT load with TIA-942 Rated 3 design. Equinix ECX Edge sits attached to the primary Sydney and Melbourne IBX campuses. AWS Local Zones cover Sydney, Melbourne, Perth and Brisbane. Microsoft Azure Edge and Google Distributed Cloud Edge cover Sydney, Melbourne and Perth. For an Australian fabricator the freight and lead-time advantage versus overseas-fabricated duct into the secondary cities is the commercial wedge.

Submarine cable landing station programme

SCLS are a specialist niche — Hawaiki, SubCom INDIGO, Telstra Endeavour, Vocus North West Cable, TPG Australia-Singapore. HVAC duct content per station is 600 to 2,000 m², with 316L coastal salt aerosol specification and PFE room positive pressure. The SBAL-V 316L 1.2 mm recipe is the workhorse, SBFB-1500 for round risers, SBSF-1525 for smoke spill. Lead time 9 to 18 months from award.

ARBS 2026 — meet the SBKJ team in Sydney

ARBS 2026 is the Australian Refrigeration, Building Services and Building Automation trade show, running in Sydney in May 2026. The SBKJ Group team will be at the show, presenting the SBAL-V auto duct production line, the SBFB-1500 spiral tubeformer and the SBSF-1525 stitchwelder configured for Australian telecom infrastructure work. The Australia Ducting Pty Ltd booth is at exhibitor ID 236.

If you are an Australian fabricator bidding into telecommunications infrastructure work — Telstra, Optus, TPG Telecom, NBN Co, Axicom, BAI Communications, Indara, Equinix, NEXTDC, AWS, Microsoft Azure or Google — ARBS 2026 is the natural venue to walk through the SBKJ machine specification, see the AS/NZS 4254.2 PLC recipes running on the demo line, and discuss the FAT certificate pack and the AS/NZS 60079 Zone 2 fabrication procedure.

What SBKJ Group brings to Australian telecom HVAC projects

• AS/NZS 4254.1 and 4254.2 PLC recipes pre-loaded on the SBAL-V auto duct production line.
• AS/NZS 60079 Zone 2 continuous TIG seam recipe for 316L stainless 1.5 mm battery extract duct.
• AS 1530.4 system documentation pack for fire-rated smoke spill duct with the matched insulation supplier.
• AS 1554.6 welder qualification records and weld procedure qualification reports.
• FAT certificate at AS/NZS 4254.2 Class C leakage minimum, with Class D available on request.
• SMACNA Seal Class A recipe overlay for projects designed by US-led consultants on the hyperscale edge DC programmes.
• Australian 415V/50Hz electrical wiring on the machine package, with HRC fuses to AS standards.
• WorkSafe-compliant safety guarding and emergency stop circuit on the line.
• ISPM-15 fumigated crating for Australian quarantine compliance.
• 72-hour WhatsApp response from the SBKJ Australia office in Box Hill North VIC during Australian business hours.
• English-speaking after-sales coordination with same time zone — no overnight delay on weekday support.
• 14 to 18 week lead time from order confirmation to commissioning in a Melbourne or Sydney shop.

Request an Australian telecom-ready SBKJ quotation →

FAQ

What ventilation standard applies to a VRLA battery room in an Australian telecom outdoor equipment shelter?

AS/NZS 60079.10.1 hazardous area classification. The battery room is Zone 2 unless dilution ventilation keeps hydrogen below 25 percent of LEL. Extract duct must be 316L stainless 1.5 mm continuous-weld TIG seam — not lockformer Pittsburgh. The extract fan is sparkless construction and wired to the DC backup so it keeps running during mains failure.

What cooling load should a 5G mobile base station outdoor equipment shelter be sized for?

5 to 15 kW continuous. Baseline 4G LTE plus 5G NR Sub-6 GHz site is 5 to 8 kW. High-density site with mmWave AAS plus edge compute pushes past 12 kW. ASHRAE TC 9.9 Class A1 (18 to 27 degrees C, 8 to 90 percent RH) is the target. SBKJ GAL 0.8 to 1.2 mm rectangular duct on the SBAL-V handles the free-cooling and supply pathway.

How is hydrogen vented from a lead-acid battery room and why does duct material matter?

Hydrogen is the lightest gas — extract grilles at ceiling level within 150 mm of the high point. Make-up air at floor level. Extract fan sparkless construction. Duct is 316L stainless 1.5 mm continuous TIG seam under AS/NZS 60079. GAL Pittsburgh seam is not acceptable. SBKJ supplies the 316L Zone 2 recipe pre-loaded on the SBAL-V.

What climate control does a telecommunications exchange require?

ASHRAE TC 9.9 Class A1 — 18 to 27 degrees C, 8 to 90 percent RH. CRAC plus raised-floor supply or hot-aisle containment. Redundant N+1 cooling. AS 1668.2 make-up air. AS 1668.1 smoke control. AS 1530.4 fire-rated compartmentation duct. AS/NZS 4254.2 Class C leakage supply duct. Power density 50 to 200 kW per rack in the IP core.

What duct gauge is required for a telco diesel generator radiator exhaust hood?

1.6 to 2.0 mm GAL or 304 stainless. The radiator extract hood is 1.6 mm. The exhaust stack base is 304 stainless 2.0 mm. SBKJ uses the SBSF-1525 stitchwelder for the heavy-gauge longitudinal seam plus the SBPC1500 plasma for the weathercap and access panel cutwork. AS 1530.4 250 degrees C for two-hour rating applies on the smoke spill pathway.

How is a submarine cable landing station climate-controlled?

Tighter than ASHRAE TC 9.9 Class A1 — typically 20 to 24 degrees C, 35 to 60 percent RH, positive pressure. PFE room is the tightest. Supply duct is 316L stainless 1.2 mm throughout because of coastal salt aerosol. Make-up air through carbon filtration plus high-grade dehumidifier. SBKJ supplies on the SBAL-V at 316L 1.2 mm recipe.

What is the lead time for SBKJ machines into an Australian telecom HVAC project?

14 to 18 weeks from order to commissioning. Breakdown: 8 to 10 weeks SBKJ production and FAT, 4 to 5 weeks sea freight, 1 to 2 weeks customs and trucking, 1 to 2 weeks site installation and commissioning. Box Hill North VIC office covers Australian business hours support.

Can SBKJ machines fabricate AS 1530.4 fire-rated smoke spill duct?

Yes. SBSF-1525 or SB-ZF1500 stitchwelder for the continuous-weld longitudinal seam, TIG-welded transverse joints, matched fire-rated insulation system on assembly. SBKJ supplies the AS/NZS 4254.2 plus AS 1530.4 system documentation pack for the fire engineering report. Pittsburgh seam is not acceptable for smoke spill.

What ductwork is needed for a Li-ion BESS battery enclosure at a telco site?

Lithium-iron-phosphate BESS sits below the hydrogen evolution threshold during normal operation, but AS/NZS 5139 requires thermal runaway extract. Off-gas is HF, CO and electrolyte vapours. Extract sized for 30 to 60 ACH during the runaway event. Duct is 316L stainless 1.5 mm, direct to atmosphere, no recirculation. Same SBAL-V 316L recipe as VRLA hydrogen venting.

Which SBKJ machine is best for an Australian fabricator targeting telecom infrastructure projects?

The SBAL-V auto duct line is the flagship, with GAL plus 316L recipes pre-loaded for AS/NZS 4254 and AS/NZS 60079. Add SBFB-1500 spiral for round duct on RAN cabinet extract. Add SBSF-1525 stitchwelder for AS 1530.4 fire-rated smoke spill. Add SBPC1500 plasma for the heavy-gauge generator stack cutwork. This quadrant covers 95 percent of the project work envelope.

How to fabricate AS/NZS 60079 and ASHRAE TC 9.9 compliant outdoor telco shelter HVAC ductwork — 8-step procedure

1. Site survey and zone classification — walk the site with the mechanical and electrical consultants. Identify each zone — RAN equipment room, DC battery room, diesel generator room, smoke spill path. Confirm hazardous area classification per AS/NZS 60079.10.1. Battery room is Zone 2 unless dilution-vented; generator fuel UST headspace per AS 1940 is Zone 1; battery acid bypass area is general atmosphere. Document the boundaries on the drawings before any fabrication starts.
2. Material schedule per zone — GAL 0.8 to 1.2 mm AS 1397 G300 Z275 for general office, equipment room supply and free-cooling economiser duct. 316L stainless 1.5 mm continuous-weld seam for the Zone 2 battery extract. 304 stainless 1.6 mm for the diesel generator radiator hood and exhaust stack base. Confirm the smoke spill duct rating per the project fire engineering report — typically 250 degrees C for two hours AS 1530.4 — and order the matched insulation system from a tested supplier.
3. SBAL-V setup for GAL rectangular duct — load 0.8 mm GAL coil onto the SBAL-V. Select 'AS/NZS 4254.1 low pressure GAL' from the PLC. The line auto-configures shear, lockformer Pittsburgh seam, TDF flange profile and corner mounting. Verify the first three pieces against the project drawing, then run continuous production. For the equipment room supply and free-cooling pathway, target Class B or better leakage at FAT.
4. SBAL-V setup for 316L Zone 2 hazardous duct — change the coil to 316L 1.5 mm. Select 'AS/NZS 60079 Zone 2 316L 1.5 mm continuous TIG seam' from the PLC. The line bypasses the lockformer (Pittsburgh seam is NOT acceptable for hazardous area duct) and routes the longitudinal seam to the TIG seam-welder station. Argon shielding 99.99 percent purity, current 90 to 110 A, travel 250 mm/min. Verify the seam against AS 1554.6 acceptance criteria — no porosity, full penetration, no undercut.
5. SBFB-1500 spiral round for RAN cabinet heat extract — set up the SBFB-1500 spiral tubeformer for the radial heat extract riser from the RAN cabinet. Typical diameter is Φ250 to Φ400 mm in GAL 0.8 mm for standard sites, or Φ500 to Φ800 mm for high-density 5G mmWave plus edge compute sites. The spiral seam is gas-tight to AS/NZS 4254 Class C at standard production rate. Add the cabinet boot in 1.0 mm GAL with TIG-welded saddle.
6. SBSF-1525 stitchwelder for smoke spill duct — for AS 1530.4 250 degrees C for two-hour smoke spill duct, fabricate the base duct on the SBSF-1525 stitchwelder. Weld the longitudinal seam continuously, then assemble the transverse joint with TIG-welded angle flanges. The Pittsburgh seam is NOT acceptable for smoke spill — confirm with the fire engineering report. Wrap the assembled duct with the matched insulation system on site, with the duct identifier tag visible through the wrap.
7. SBPC1500 plasma cutter for the diesel generator exhaust stack — for the diesel generator exhaust stack weathercap, mitre transitions, access panels and instrument penetrations, use the SBPC1500 plasma cutter. The stack base is in 304 stainless 1.6 mm (or 2.0 mm for high-temperature continuous-duty installations), cut from 1500 mm sheet on the plasma bed. The mitres are fabricated as separate segments then TIG-welded for the inline joints. Hot-side seams use full-penetration TIG with backing argon.
8. FAT testing, certification and AS/NZS 4254 Class C documentation — conduct factory acceptance testing on a representative production sample. AS/NZS 4254.2 Class C leakage at design pressure for the supply duct. AS 1530.4 system documentation for the smoke spill duct (the system, not the bare duct, is fire-rated). 316L Zone 2 seam macro and tensile test certificates. AS 1554.6 weld procedure qualification and welder qualification records. Issue the FAT certificate pack to the project mechanical consultant before delivery. Box Hill North VIC office reviews and counter-signs the pack within Australian business hours.

Closing — speak to the SBKJ Australia team

Australian telecommunications infrastructure is one of the most demanding HVAC environments on the continent. The standards stack is wider than commercial office work and the operator-side compliance audit is unforgiving. An Australian fabricator with the right SBKJ machine package, welder qualification, FAT certificate pack and hazardous-area training records is the supplier the Tier 1 mechanical and electrical contractor wants on their tender shortlist for Telstra, Optus, TPG, NBN Co, Axicom, BAI, Indara, Equinix, NEXTDC and the hyperscale edge DC operators.

SBKJ Group's Australia office is at Box Hill North VIC, with 72-hour WhatsApp response and ARBS 2026 in Sydney in May — Australia Ducting Pty Ltd booth, exhibitor ID 236.