Solar PV Cell, Module, Perovskite, Tracker & Recycling Manufacturing HVAC Duct Guide

Why this guide treats four facility types in one document

Solar photovoltaic manufacturing is not one industry — it is a vertically-stacked set of four distinct industrial verticals, each with its own HVAC ductwork problem, but each sharing enough engineering DNA that an Australian mechanical contractor pricing one project is almost certainly pricing the next. A working silicon PV cell line in the Sun Drive Solar or Tindo Solar pattern is at one extreme a near-semiconductor cleanroom and at the other a heavy-chemical wet bench. A perovskite research lab at ANU or UNSW is a lab-scale operation but handles lead at a workplace exposure standard tighter than any silicon process. A solar tracker assembly shop building Nextracker, Array Technologies or 5B Maverick units is a steel fabrication workshop with welding fume and paint booth scope. And a PV recycling plant — Reclaim PV Recycling in Adelaide, the Lotus Energy ANU pilot in Canberra — is a hybrid of mechanical processing dust extraction and chemical recovery wet bench scope. Across all four, the duct material schedule, the seal class, the hazardous area classification and the SBKJ machinery configuration repeat with minor variations.

This guide is the working reference SBKJ engineers hand to the mechanical contractor, the process engineer and the procurement lead before they specify a single metre of duct for any of these four facility types. It is written from the Box Hill North, Victoria bench — Australian standards (AS 1668.2, AS 4254, AS 1530.4, AS/NZS 60079, AS 1851, AS 4332, AS 1604, AS 1940, AS/NZS 4836, AS 1715, AS/NZS 4509, AS/NZS 5033) first, with ASHRAE, ISO, IEC, SEMI and ANSI references where they add precision the Australian set does not. The numbers, materials and tolerances are real and current. The SBKJ machine references are the production catalogue, not aspirational. Where SBKJ ductwork machinery is the right tool, we say so. Where the project needs FRP from a specialist plastic fabricator or HEPA-grade housings from a filter vendor, we say so as well.

Across the four facility types the common engineering thread is the duct material schedule. Galvanized G90 carbon steel to ASTM A653 or AS 1397 Z275 is the workhorse for everything that is not chemistry-loaded — module assembly, tracker workshop supply and return, PV recycling shred hall general air, perovskite lab supply, warehouse and amenities. The 316L stainless steel switch-over point is consistent: any duct downstream of a hot caustic bath (KOH or NaOH wafer texturing), any duct between an acid wet bench enclosure and the inlet of a scrubber unit, any duct downstream of a silane PECVD chamber and upstream of the thermal oxidiser, any duct in an ammonia toxic-gas zone, any duct in a chemical recovery wet bench on the recycling line. The hydrofluoric acid wet bench primary extract — the path from the HF dip tank hood to the inlet of the fluoride scrubber — is the one place where SBKJ does not have a duct material answer, and the project must specify FRP with vinyl-ester or furan resin or polypropylene from a specialist plastic fabricator. 304L stainless is acceptable but rarely justified — the 316L upgrade is small in absolute cost and removes the second-tier chloride concern in coastal sites like Adelaide, Newcastle, Brisbane and the Pilbara that increasingly host PV manufacturing.

The hazardous gas profile is the strongest single argument for treating these four verticals together. Silane (SiH4), phosphine (PH3), diborane (B2H6), ammonia (NH3) and chlorine (Cl2) all appear at industrial concentration somewhere across the solar manufacturing stack — silane in PECVD anti-reflection coating, phosphine and diborane in cell doping, ammonia in SiNx PECVD and in some recycling chemistries, chlorine in POCl3 diffusion exhaust. Each has a Safe Work Australia workplace exposure standard, each demands AS/NZS 60079.10.1 zoning, each requires multi-gas detection, each requires spark-resistant fans and ATEX or IECEx motors. The HVAC duct system is the primary engineered control between a credible gas release and a workplace exposure or a deflagration. Get the duct scope wrong and the safety case will not approve, and the line will not start.

Australian context — Sun Drive, Tindo, 5B, ANU and the manufacturing pivot

Australia's position in the global PV value chain has been almost entirely upstream — silicon mineral, polysilicon refining demand from the WA gas fields, and at the downstream end residential and commercial installation at world-leading per-capita rates. Australian solar cell and module manufacturing has been a small industry for two decades, but the past three years have shifted decisively. The Federal Government's Solar Sunshot Program, announced in 2024 with ARENA administering up to $1 billion in production credits and capital grants, has triggered the most concentrated round of Australian PV manufacturing announcements since the 1990s.

The leading Australian operators we see on duct enquiries fall into four groups. The first group is the silicon PV cell + module manufacturers. Sun Drive Solar at Lugarno in southern Sydney, NSW, leads the technology pack — their copper-plated silicon cell technology held the world efficiency record for commercial-format heterojunction cells and they raised over $500 million in 2024 with ARENA, AGL Energy and Blackbird VC backing for a multi-gigawatt commercial scale-up. Tindo Solar at Mawson Lakes in Adelaide, SA, is Australia's only Tier 1 PV module manufacturer and currently the only meaningful domestic module producer at any scale, running a 60 MW per year line that is set to expand significantly. Vulcan Energy through Vulcan Manufacturing has signalled cell line ambitions. SunPower Australia, now operating primarily as a distribution channel, was historically a manufacturer and remains a benchmark for module-level engineering standards.

The second group is solar tracker manufacturers and assembly partners. 5B Solar, Sydney-headquartered, designs and assembles the Maverick prefabricated solar array — folding ground-mount units that ship globally and deploy in hours. Nextracker and Array Technologies are US-domiciled but maintain Australian assembly and supply partners for large utility tenders. PV Hardware, Spanish-origin, has Australian tracker assembly through partner workshops. Sun Drive Solar additionally assembles a proprietary single-axis tracker. Tigo Energy, US-domiciled with Australian sales presence, supplies module-level power electronics that integrate at the module assembly station.

The third group is the perovskite and cell research community. ANU Solar Research in Canberra, ACT, holds the world tandem perovskite-silicon cell efficiency record across multiple generations under Professor Andrew Blakers and colleagues. UNSW Solar at Sydney, the Martin Green Lab and Scientia line, was the institution that invented the Passivated Emitter Rear Contact (PERC) cell architecture now dominant in global production and continues to lead the next generations. Monash Solar at Melbourne is the Australian academic centre for perovskite-tandem and solid-state PV chemistry. UQ Solar at the University of Queensland, supported by Halocarbon Capital, conducts encapsulant and module reliability research. CSIRO Energy at Newcastle, NSW, and Clayton, VIC, conducts industrial-scale PV research with a particular focus on perovskite stability, module reliability and recycling chemistry. ARENA funding underwrites large segments of this research.

The fourth group is the PV recycling sector. Reclaim PV Recycling in Adelaide, SA, is the Australian industry's primary panel takeback and recycling operator, processing end-of-life modules through delamination and recovery. Lotus Energy ANU in Canberra, ACT, conducts pilot-scale PV recycling research focused on silver and silicon recovery chemistry. Resource Recovery Australia handles broader e-waste streams with PV as one fraction. Sims Lifecycle Services covers the wider e-waste regulated streams under WEEE Australia rules.

The industry bodies and standards setters round out the picture. The Clean Energy Council (CEC) sets the Approved Products Lists that any module sold in Australia must appear on, with CEC accreditation now demanding IEC 61730 (PV module safety qualification) and IEC 61215 (performance qualification). The Smart Energy Council represents the installer and dealer channel. The Australian PV Institute (APVI) maintains industry-wide data and benchmarks. The Australian Renewable Energy Agency (ARENA) is the funding instrument. The Solar Cleaning and Maintenance Industry Code covers the operational side. And the large EPC and utility-scale developers — AGL Energy (ASX:AGL), Origin Energy (ASX:ORG), Genex Power (ASX:GNX), Neoen Australia, BBE BlackRock, Lyon Group, Beyond Solar — buy the modules and trackers that come out of these factories, generating the pull-demand that justifies the manufacturing investment.

Silicon PV cell manufacturing — process flow and HVAC consequences

A modern Australian silicon PV cell line in the Sun Drive Solar or Tindo Solar pattern is a sequence of approximately ten major process steps, each with its own HVAC consequence. The dominant chemistry is the wet bench (caustic and acid), the dominant hazard is the silane PECVD bay, and the dominant cleanliness driver is the screen printing and metallisation line. The duct schedule across the line is approximately 40 to 55 percent stainless (304L and 316L), 10 to 15 percent FRP or PP (HF exhaust to scrubber, refer to plastic fabricator), and the remainder galvanized.

Wafer incoming and saw damage etch

Incoming silicon wafers — typically 156 to 210 millimetre square, M10 or M12 format — arrive with saw damage from upstream wire-saw cutting that must be removed before cell processing can begin. The first wet bench operation is a hot caustic etch in 5 to 10 percent potassium hydroxide or sodium hydroxide at 70 to 85 degrees Celsius, removing 5 to 10 micrometres of damaged silicon. The bath generates a caustic mist — KOH or NaOH droplets suspended in saturated water vapour — that must be extracted at the wet bench enclosure hood and routed through a caustic mist eliminator to a 316L scrubber. The duct from the bench enclosure to the scrubber inlet is 316L stainless because 304L galvanized and aluminium are all attacked by hot caustic mist within months. Capture velocity at the wet bench hood is 0.5 m/s minimum to AS/NZS 1715 standard. The scrubber housing is 316L with FRP or PP packed bed internals; discharge is to a stack typically 5 to 7 metres above roof.

Alkaline texturing — pyramid etch

The same hot caustic bath, often with a chemical additive to give random pyramid texturing rather than planar etch, creates the cell front surface texture that reduces reflection by trapping incident light. The HVAC scope is identical to the saw damage etch — 316L stainless duct to a 316L scrubber. Many modern Australian lines combine saw damage etch and texturing in a single bench module with shared exhaust.

Acid wet bench — phosphosilicate glass and oxide removal

After diffusion (see below) the wafer carries a layer of phosphosilicate glass (PSG) that must be removed by a dip in dilute hydrofluoric acid, typically 5 to 10 percent HF, sometimes mixed with hydrochloric acid (HCl) to also strip metallic contamination. This is the single most aggressive duct corrosion problem on the cell line, and the only operation where SBKJ does not supply the primary extract duct. The path from the HF dip tank enclosure hood to the inlet of the fluoride-specific scrubber is fibreglass-reinforced plastic (FRP) with vinyl-ester or furan resin, or polypropylene (PP), fabricated by a specialist plastic ductwork shop. Capture velocity 0.5 m/s minimum. The fluoride scrubber is a packed-bed type with caustic recirculation that neutralises the HF to calcium fluoride or similar precipitate. The scrubber housing is 316L stainless with FRP internals (or all-FRP); the post-scrubber discharge duct is 316L stainless to the stack.

SBKJ supplies the 316L stainless scrubber housing fabrication via the SB-ZF1500 stitchwelder and the discharge stack via the SBAL-V auto duct line. The intermediate FRP scope sits outside the SBKJ catalogue and is referred to specialist plastic fabricators — Ducon Plastics, Trans-Plastic and similar Australian vendors handle this scope routinely. The cost split is approximately 60 percent FRP/specialist, 40 percent SBKJ stainless on the fluoride circuit.

POCl3 phosphorus diffusion furnace

The n+ emitter is formed by diffusing phosphorus into the rear of the cell using phosphorus oxychloride (POCl3) as the dopant source, typically at 800 to 900 degrees Celsius in a tube furnace. POCl3 is toxic and corrosive — Safe Work Australia treats POCl3 as a Class 6.1 toxic substance with WES set conservatively against phosphine (PH3) at 0.3 ppm TWA and 1 ppm STEL because POCl3 decomposes to release PCl3 and PH3 on contact with moisture. The furnace exhaust must therefore be:

• 316L stainless duct from the furnace exhaust manifold through to the acid scrubber. Continuous welded seams. Capture velocity 0.5 m/s at the furnace door during loading/unloading.
• Acid scrubber with caustic recirculation neutralising PCl3 and HCl byproducts to phosphate and chloride salts. Scrubber housing 316L, internals FRP.
• Multi-gas detection for phosphine (0.3 ppm alarm 1, 1 ppm alarm 2) and PCl3 at the furnace cabinet and the bay ceiling, integrated with the furnace control system to interlock the dopant flow on detected alarm.
• Dilution ventilation in the diffusion bay at 15 to 25 ACH to manage worst-case credible leak.

Silicon nitride (SiNx) PECVD anti-reflection coating

The silicon nitride anti-reflection coating that gives a solar cell its characteristic blue colour is deposited by plasma-enhanced chemical vapour deposition (PECVD) using silane (SiH4) and ammonia (NH3) precursors at 350 to 450 degrees Celsius. This is the single most demanding HVAC zone on the entire silicon PV cell line because silane is pyrophoric — it auto-ignites in air at concentrations above approximately 1 percent without an ignition source, and at lower concentrations a static spark is sufficient to ignite a hydrogen flame. Safe Work Australia sets the silane WES at 5 ppm TWA and 10 ppm STEL.

The HVAC consequences are categorical:

• AS/NZS 60079.10.1 Zone 1 classification inside every silane gas cabinet enclosure, with Zone 2 in the surrounding bay. The cabinet exhaust runs continuously at 8 to 12 m/s capture velocity through dedicated ducts to the silane thermal oxidiser.
• Dilution ventilation in the PECVD bay sized to dilute the worst-case credible silane leak below 25 percent of LFL (treated as 1 percent v/v threshold for silane in air). For a typical 100 to 300 sccm leak from a gas cabinet manifold, this translates to 6,000 to 20,000 cubic metres per hour of dilution per cabinet.
• 316L stainless ductwork from the PECVD chamber pump exhaust to the thermal oxidiser inlet, with continuous welded seams. Insulation to maintain duct skin temperature above 80 degrees Celsius to prevent the silicon dust byproduct from depositing on cool surfaces — accumulated silicon dust in cool sections is a fire risk if disturbed.
• Spark-resistant exhaust fans with non-sparking aluminium-bronze impellers, ATEX or IECEx Zone 1 certificates, Ex-d flameproof motors, and ATEX-rated motor cable glands. The fan certificate number is recorded on the project schedule and verified against the AS/NZS 60079.14 register.
• Multi-gas detection for silane (5 ppm alarm 1, 10 ppm alarm 2), ammonia (25 ppm alarm 1, 35 ppm alarm 2) and hydrogen (0.4 percent alarm 1, 1 percent alarm 2) at the gas cabinet, the bay ceiling and the exhaust riser, integrated with the silane manifold isolation valve and the bay evacuation alarm.
• Earthing of every duct section, every flange and every penetration to the building equipotential reference per AS/NZS 60079.14. Resistance below 1 ohm between adjacent sections, verified at commissioning and annually thereafter.
• Thermal oxidiser at the end of the silane exhaust train, combusting the silane to silicon dioxide and water at 800 to 1000 degrees Celsius. The combustion products are non-toxic and the silicon dioxide is captured on a downstream baghouse filter before atmospheric discharge.

The TOPCon, PERC and HJT (Heterojunction) cell architectures all use silane PECVD in some form. HJT lines additionally use silane in amorphous silicon (a-Si) buffer layer deposition at lower temperatures (around 200 degrees Celsius) and add atomic layer deposition (ALD) chambers with separate exhaust requirements. The duct scope and zoning principles are identical to the SiNx PECVD case above.

Aluminium back surface field (BSF) and screen printing

The aluminium back surface field is a screen-printed paste applied to the rear of the cell that creates the back contact and additional electrical isolation. The line passes through screen printing (silver paste front, aluminium paste rear), a drying oven and a co-fire furnace at 700 to 900 degrees Celsius where the pastes sinter to bonded metal. The HVAC consequence is solvent vapour extraction from the screen printing area and the drying oven — typical solvents are terpineol, IPA (isopropyl alcohol, WES 400 ppm TWA), butyl carbitol and similar oxygenated solvents. The extract duct is 304L stainless or galvanized depending on the solvent loading, with capture velocity 0.5 m/s and a regenerative thermal oxidiser (RTO) or activated carbon abatement before discharge.

The screen printer itself runs at cleanroom Class 7 to 8 cleanliness to prevent particle inclusion in the metallisation tracks. Silver dust generation during paste handling is captured at source with HEPA-filtered local exhaust. Personnel exposure to silver is monitored against the Safe Work Australia WES of 0.1 mg/m³.

The co-fire furnace exhaust handles solvent vapour, organic binder pyrolysis products and trace metallic fume from the silver and aluminium sintering. 304L stainless duct, RTO abatement, capture at the furnace door during loading.

Cell testing, sorting and binning

Each completed cell is electrically characterised by an I-V curve test (typically under simulated AM 1.5G illumination) and an electroluminescence (EL) image for defect detection. This is a clean climate-controlled environment, ISO 14644 Class 7, but no significant exhaust or hazardous gas scope. Galvanized supply and return is sufficient.

Module assembly — tabbing, stringing, laminating, framing

The module assembly line takes finished cells and integrates them into the finished PV module. The line is much less HVAC-intensive than cell manufacturing — cleanliness is typically ISO Class 7 to 8 or controlled non-classified, hazardous gases are absent, and the dominant duct scope is solder fume capture and EVA encapsulant lamination extract.

Tabbing and stringing

Individual cells are connected in series using ribbon wire (typically copper coated with tin-lead or tin-silver solder) and the strings are interconnected to form the module circuit. The process generates solder flux fume that must be captured at source per AS/NZS 1715. Older lines using tin-lead (Sn63/Pb37) solder generate lead-containing fume that is regulated to the Safe Work Australia WES of 0.05 mg/m³ TWA — at this level dedicated HEPA-filtered local exhaust is mandatory at every tabbing/stringing station and personnel breathing zone monitoring is required. Modern lines using lead-free (Sn-Ag-Cu) solder relax the lead constraint but the tin and silver fume still requires source capture.

The duct from the local capture hood is 304L stainless or galvanized depending on the flux chemistry — rosin-based fluxes are acceptable on galvanized, water-soluble fluxes on 304L. HEPA filtration on the discharge.

Module lay-up and EVA encapsulant lamination

The cell string is sandwiched between front glass, encapsulant (typically EVA — ethylene vinyl acetate, or POE — polyolefin elastomer) and a backsheet (Tedlar or polyolefin). The sandwich is passed through a heated vacuum laminator at 140 to 150 degrees Celsius and approximately 14 bar for 25 to 30 minutes. The laminator is a sealed cycle, so steady-state extract is minor — galvanized duct sized for occasional purge cycles is sufficient. Some EVA formulations release acetic acid on degradation; if the project material data sheet shows this, upgrade to 304L stainless for the laminator extract.

Framing, junction box and final test

Aluminium frames are mechanically clinched or bonded to the module edges with butyl seal tape. The junction box is bonded to the rear of the module with silicone potting and the cell strings are terminated to the junction box bus bars. The high-pot insulation test, the flash test (I-V curve under simulated AM 1.5G), and the electroluminescence (EL) test verify module performance per IEC 61215 (performance) and IEC 61730 (safety) — the standards underpinning Clean Energy Council Approved Products List qualification. HVAC is conventional galvanized supply and return; clean climate controlled to ISO Class 8.

Perovskite cell research — the lead-controlled lab

Perovskite cell research in Australia is concentrated at four academic institutions and one industrial research lab: ANU Solar Research, UNSW Solar, Monash Solar, UQ Solar and CSIRO Energy. The scale is laboratory rather than industrial — typical fabrication chambers process single-cell or small-area samples — but the HVAC scope is disproportionate to size because the active layer chemistry centres on lead iodide (PbI2) and methylammonium iodide (MAI), and lead exposure is regulated to the Safe Work Australia WES of 0.05 mg/m³ TWA. This is an order of magnitude tighter than the dilution case for any silicon PV bay.

The lab HVAC scope splits into three zones:

• Perovskite synthesis and precursor handling. Lead iodide and methylammonium iodide precursors are weighed and dissolved in dimethylformamide (DMF, WES 10 ppm TWA), dimethyl sulfoxide (DMSO, WES 1 mg/m³ skin) or gamma-butyrolactone (GBL). The fume hood handling these operations is a laboratory walk-in fume hood with HEPA aerosol filtration on the discharge to capture any aerosolised lead. Duct from hood to filter is 316L stainless; post-filter to stack is 304L stainless or galvanized. Capture velocity at the hood face is 0.5 m/s minimum to AS/NZS 2243.8.
• Perovskite layer deposition. The dominant techniques are spin coating (in an inert glove box or in a fume hood) and slot-die coating for larger areas. Each deposition uses chlorobenzene, toluene or other antisolvents as a quench step, adding a flammable vapour load that requires AS/NZS 60079.10.1 Zone 2 classification inside the fume hood. The spin coater enclosure is fume-extracted at 0.5 m/s, 316L stainless duct, HEPA filter on discharge for lead capture. The chlorobenzene WES is 10 ppm TWA / 50 ppm STEL.
• Annealing and electrode deposition. The perovskite layer is thermally annealed at 100 to 150 degrees Celsius to crystallise, then capped with a hole transport layer (Spiro-OMeTAD or PTAA) and a metal electrode (typically gold or silver) via thermal evaporation in a vacuum chamber. Vacuum chamber roughing pump exhaust runs through an oil mist filter and an activated carbon canister before atmospheric discharge. The thermal evaporator has minimal HVAC scope beyond the chamber pump exhaust.

The personnel exposure regime is the dominant operational consideration. Each researcher in the perovskite synthesis bay carries a personal lead exposure dosimeter; air monitoring at fixed locations is logged continuously. The flooring is sealed and lead-decontamination-rated (typically welded vinyl or epoxy). Glove boxes, fume hoods and spin coaters are cleaned with HEPA vacuum after each campaign. SBKJ fabricates the 316L stainless general lab exhaust and the galvanized supply; the HEPA-grade lead recapture filter housings and chemical-resistant flex (PTFE-lined) are sourced from specialist filter vendors.

A typical Australian university perovskite research bay (ANU, UNSW, Monash) is 50 to 200 square metres with 6 to 12 fume hoods and 2 to 4 spin coater enclosures. The duct scope is small in absolute terms — perhaps 500 to 1,500 square metres of formed duct — but high-margin because the stainless content is high and the regulatory documentation is intensive. SBKJ fabricates the entire scope using the SBAL-V auto duct line and the SBSF-1525 lockformer.

Tandem and high-efficiency architectures — TOPCon, HJT, perovskite-silicon

The Australian PV research community and the leading commercial cell line (Sun Drive Solar) are both moving beyond the conventional PERC architecture toward higher-efficiency alternatives. The HVAC consequence varies by architecture.

TOPCon (Tunnel Oxide Passivated Contact). A variant of n-type cell architecture using a thin tunnel oxide and a polysilicon passivation layer on the rear. The HVAC consequence is one additional PECVD chamber (depositing the polysilicon layer using silane and hydrogen) plus an annealing furnace. The duct schedule is essentially the same as a PERC line with 10 to 20 percent more silane PECVD duct.

HJT (Heterojunction). Uses amorphous silicon a-Si:H passivation layers deposited by PECVD at low temperature (around 200 degrees Celsius), with a transparent conductive oxide (TCO — indium tin oxide or aluminium-doped zinc oxide) deposited by sputtering. The HVAC consequence is increased silane usage in the a-Si:H chambers, plus an indium-containing sputter target exhaust line. Sun Drive Solar's copper-plated HJT process additionally adds a copper electroplating wet bench downstream of the TCO — copper sulphate bath at 30 to 40 degrees Celsius, exhausted to a 316L stainless duct, no major hazardous gas scope but minor acid mist.

Perovskite-silicon tandem. The high-efficiency next generation — a perovskite top cell deposited on a silicon bottom cell, currently the world record holder for two-junction cell efficiency. ANU Solar Research holds the running world record for laboratory-scale tandems. The HVAC consequence is the combination of a silicon PECVD bay (for the bottom cell finishing) and a perovskite deposition bay (for the top cell), with the lead exposure regime of the perovskite work applied to the entire downstream process. Commercial-scale tandem manufacturing is not yet established in Australia — when it arrives (2027-2030 timeframe), the HVAC duct scope will combine the silicon cell case and the perovskite case in a single building, with the lead control governing the integration.

Solar tracker assembly — Nextracker, Array Technologies, PV Hardware, 5B Maverick, Sun Drive

Solar tracker mechanical assembly is the third major facility type in this guide and is, paradoxically, the simplest from an HVAC perspective. A tracker assembly workshop is essentially a steel fabrication shop with welding, painting and mechanical assembly stations. There is no cleanroom, no hazardous gas, no scrubber. The HVAC scope is:

• General workshop supply and return in galvanized G90 to AS/NZS 4254 Class B, sized to AS 1668.2 occupant rates. Air change rate 4 to 6 ACH, conventional ceiling diffusers, side-wall return.
• Welding fume capture at every weld station. Tracker torque tubes are typically welded from galvanized or zinc-rich primed steel; the welding process generates iron oxide, zinc oxide and trace manganese fume. Source capture at 0.5 m/s minimum face velocity per AS/NZS 1715, ducted to a downflow filter or a cartridge dust collector. Hood and duct in 1.5 mm galvanized or 304L stainless. Zinc oxide fume is regulated to the Safe Work Australia WES of 5 mg/m³ TWA / 10 mg/m³ STEL.
• Paint booth bays for galvanized or zinc-rich primer application on tracker components that are not factory-galvanized. AS 1668.2 paint booth ventilation at 0.4 to 0.5 m/s booth face velocity, exhaust through dry filter or water wash abatement, discharge to atmosphere. Booth construction in galvanized panel with stainless internals.
• Mechanical assembly stations with conventional supply and return — bearing pressing, slew drive integration, motor coupling, electrical wiring, final torque check. Standard galvanized HVAC scope.
• QA test bay for tracker dynamic test — load cycling, wind simulation, electrical commissioning. Clean climate-controlled but no special HVAC.

A typical Australian tracker assembly workshop sized for 300 MW per year (5B Maverick scale, Sun Drive tracker scale) is 6,000 to 12,000 square metres of floor area, running 4,000 to 8,000 square metres of formed duct. The SBAL-V auto duct line covers the entire scope with one machine running single-shift over 4 to 8 weeks; the SBSF-1525 Pittsburgh lockformer handles the manual fittings; the SBPC1500 plasma cutter handles the welding hood blanks and any custom transitions. SB-ZF1500 stitchwelding is used on any 304L stainless welding hoods that need continuous-weld seal class.

5B Solar's Maverick product is a distinctive case — the unit is largely pre-assembled at the workshop and shipped as a folded structure that unfolds on site. The workshop layout is more like an automotive assembly line than a traditional tracker shop, with stations dedicated to specific operations. The HVAC scope is still conventional galvanized supply and return plus welding capture; the difference is the workshop bay layout, not the duct material.

PV recycling — Reclaim PV, Lotus Energy ANU, the e-waste pivot

PV recycling is the fourth and youngest facility type covered in this guide. Australia's residential and commercial PV deployment over the past two decades — currently approaching 4 million households with rooftop systems — is now generating end-of-life modules at a scale that demands organised recycling infrastructure. The regulatory framework is the WEEE Australia E-waste rules and the National Television and Computer Recycling Scheme, both of which now bring PV modules into scope.

Reclaim PV Recycling at Adelaide is the Australian industry's leading operator, processing modules through frame removal, glass shredding and EVA delamination. Lotus Energy ANU at Canberra is the academic counterpart, focusing on silver and silicon recovery chemistry. The HVAC duct scope across these facilities is real but bounded — typical plant runs 5,000 to 15,000 square metres of formed duct depending on throughput.

Mechanical processing

The mechanical stages are frame removal (manual or mechanical), glass shredding and milling, and EVA delamination (thermal or chemical). HVAC scope:

• Frame removal bay — manual workshop with conventional galvanized supply and return.
• Glass shredder dedicated dust extraction — HEPA-filtered, 18 to 22 m/s transport velocity in galvanized or 304L stainless duct. PV cells in older modules (pre-2010 lead solder formulations) contain lead and tin traces above the 0.05 mg/m³ WES limit, so HEPA H13 minimum on the discharge and continuous personnel exposure monitoring at the shredder operator station. Tin oxide fume can also generate during shredding of older modules and is monitored to the Safe Work Australia WES.
• EVA delamination thermal step — the encapsulant is removed from the cell at 400 to 500 degrees Celsius, generating organic vapour (acetic acid, formaldehyde — WES 1 ppm STEL, smaller hydrocarbons). Extract through activated carbon abatement before discharge, 304L stainless duct.

Chemical recovery

Silver and silicon recovery from the delaminated cells uses nitric acid (HNO3) and hydrofluoric acid (HF) in wet bench operations broadly similar to the PV cell wet bench but at smaller scale. The duct scope mirrors the cell line:

• FRP or PP duct from the HF/HNO3 wet bench enclosure to the fluoride scrubber (referred to specialist plastic fabricator).
• 316L stainless scrubber housing and post-scrubber discharge to stack.
• Multi-gas detection for HF, HCl and NOx in the wet bench bay and the exhaust stack.
• Acid storage per AS 4332 specialty gas and AS 3780 acid storage requirements; bunded cabinets with dedicated exhaust ventilation.

The plant is regulated under WEEE Australia rules, Safe Work Australia WES for the metals (lead, silver, tin) and acids, and the relevant state EPA discharge consents. The HVAC commissioning evidence pack is part of the operations licence documentation.

Hazardous gas profile — the silane, phosphine, diborane, ammonia, chlorine, HF, NF3 set

The seven specialty gases that recur across PV cell, perovskite and recycling operations define the safety case for the entire HVAC duct scope. Each has a Safe Work Australia workplace exposure standard, an AS/NZS 60079 zone classification, and a specific detection and ventilation regime.

Silane (SiH4). WES 5 ppm TWA / 10 ppm STEL. Pyrophoric — auto-ignites in air above approximately 1 percent v/v. Zone 1 inside the gas cabinet, Zone 2 in surrounding bay. Spark-resistant fans, Ex-d motors, dilution to below 25 percent LFL (treated as 0.25 percent v/v for safety margin). Discharge via thermal oxidiser to silicon dioxide and water. Used in SiNx PECVD, a-Si HJT, polysilicon TOPCon, ALD chambers.

Phosphine (PH3). WES 0.3 ppm TWA / 1 ppm STEL. Extremely toxic — half the lethal dose at the WES level. Toxic-gas controlled rather than explosive at typical process concentrations. 316L stainless duct, dedicated extract from the gas cabinet at 8 to 12 m/s capture velocity, multi-gas detection at the cabinet, bay and stack. Used as a dopant in n-type cell architectures (POCl3 alternative for some processes) and in some III-V research applications.

Diborane (B2H6). WES 0.1 ppm TWA. Extremely toxic and pyrophoric in higher concentrations. Same control measures as phosphine plus the silane-grade dilution and spark-resistant fans. Used as a dopant in p-type architecture and in some BSG (borosilicate glass) diffusion processes.

Ammonia (NH3). WES 25 ppm TWA / 35 ppm STEL. Toxic and corrosive to copper, brass and bronze. 316L stainless duct, dedicated extract, multi-gas detection. The NH3 supply to the SiNx PECVD is the dominant Australian PV cell ammonia load. Eliminate copper from the airstream in NH3-loaded zones — including motor windings, refrigerant coils and any control valves.

Chlorine (Cl2). WES 0.5 ppm TWA / 1 ppm STEL. Toxic and corrosive. Used in some PV cell etch processes and in chemical recovery on the recycling line. 316L stainless duct, dedicated scrubber with caustic recirculation.

Hydrogen fluoride (HF). WES 1.8 mg/m³ TWA (approximately 2 ppm). Extremely corrosive — attacks 304L stainless and aluminium. The PV wet bench texturing and PSG removal step is the primary HF source. FRP or PP duct from the wet bench to the scrubber inlet (specialist fabricator); 316L stainless scrubber housing and discharge.

Nitrogen trifluoride (NF3). WES 10 ppm TWA. Used as a PECVD chamber clean gas in some processes — etches silicon and silicon nitride deposits between production runs. NF3 itself is a potent greenhouse gas (GWP 17,200 over 100 years) and is regulated under the National Pollutant Inventory. Extract through abatement (typically a hot ammonia scrubber that converts NF3 to nitrogen and ammonium fluoride) before discharge. 316L stainless duct.

The other gases that appear in the WES register and are worth flagging — sulphur hexafluoride (SF6, no formal WES but GWP 23,500 over 100 years, used as a PECVD chamber clean in some processes), ozone (0.1 ppm WES, generated at UV cure stations), formaldehyde (1 ppm STEL, from some encapsulant degradation), and the solvent set (IPA 400, acetone 500, MEK 200 ppm TWA — all relevant in screen printing and module assembly).

Cleanroom classification — ISO 14644-1 Class 5, 6, 7, 8 across the PV stack

Solar PV manufacturing cleanroom requirements are looser than semiconductor logic but tighter than pharmaceutical solid-dose. The typical class allocation across the cell + module line:

• ISO Class 5 — reserved for the highest-efficiency cell metrology stations and a few HJT or TOPCon-specific deposition zones where particle inclusion in the metallisation track has direct yield consequence.
• ISO Class 6 — typical for the wet bench bays, the diffusion furnace bay, the PECVD bay and the screen printing line on a mainstream c-Si cell process. Air change rate 15 to 25 ACH, HEPA H13 terminal filters, F9 prefilter at the AHU.
• ISO Class 7 — the rest of the cell line including handling, sorting and the front end of module assembly. ACH 10 to 15.
• ISO Class 8 — module assembly framing, junction box installation, flash test and EL test. Typically the loosest classified zone, ACH 5 to 10.
• Controlled non-classified (CNC) — module storage, warehouse, tracker assembly workshop, recycling shred hall. Conventional HVAC scope, ACH 4 to 8.

The duct material consequence of the cleanroom class is incremental. ISO Class 5 stations demand 316L stainless supply ducts with electropolished interior finish on the wetted face upstream of the terminal HEPA — this is the same standard as a semiconductor mid-tier cleanroom. ISO Class 6 stations accept 316L with 2B mill finish. ISO Class 7 accepts 304L stainless with 2B mill finish, or galvanized in zones where chemistry permits. ISO Class 8 is conventional galvanized G90.

The pressure cascade across the cleanroom holds the wet bench and process gas bays at slight negative pressure (5 to 12.5 Pa below adjacent corridor) to contain chemistry, while the metrology and incoming wafer bays are at positive pressure (12.5 to 25 Pa above adjacent corridor) to exclude ambient particles. Pressure cascade is verified at commissioning under both static and dynamic (door-open) conditions.

Materials selection by zone — the 316L stainless rule

Across the four PV facility types covered in this guide, the duct material rules consolidate into a manageable set:

• FRP or PP duct (refer to specialist plastic fabricator — not SBKJ scope): primary HF and fluoride extract from wet bench enclosure to scrubber inlet. Vinyl-ester or furan resin FRP, or polypropylene. Diameter typically 200 to 600 mm round. Pressure rating to handle worst-case static plus surge.
• 316L stainless steel (ASTM A240 Type 316L, AS 1449): caustic mist exhaust from KOH/NaOH wafer texturing, acid scrubber duct downstream of the FRP primary extract, silane and dopant gas cabinet exhaust to thermal oxidiser, POCl3 diffusion furnace exhaust, NH3 PECVD exhaust, NF3 chamber clean exhaust to abatement, perovskite lab HEPA-filtered lead extract, recycling chemical recovery wet bench scrubber. 0.8 to 1.5 mm thickness on the SBAL-V auto duct line.
• 304L stainless steel (ASTM A240 Type 304L, AS 1449): general PV cell cleanroom ISO Class 7 supply, screen printing line solvent extract, EVA encapsulant minor extract (if acetic acid present), welding fume capture where galvanized is undersized, ISO Class 6 supply (if chemistry permits and 316L is not justified). 0.6 to 1.5 mm thickness.
• Galvanized G90 carbon steel (ASTM A653, AS 1397 Z275): module assembly supply and return, tracker workshop general supply and return, recycling shred hall general air, perovskite lab supply, warehouse, amenities, ISO Class 8 zones, all CNC zones. 0.6 to 1.5 mm thickness, standard SBAL-V output.
• Aluminium-bronze impeller fan, Ex-d motor: mandatory on every silane, phosphine, diborane, hydrogen and NF3 exhaust fan. ATEX or IECEx Zone 1 certificate.

The cost differential is significant but bounded. 316L stainless ductwork at installed cost runs approximately 2.2 to 2.6 times galvanized in 2026 Australian market pricing; 304L is approximately 1.6 to 2.0 times. The material cost component is roughly 40 percent of installed price; fabrication labour is 25 percent; installation labour 20 percent; insulation and accessories 15 percent. The fabrication labour share is what local on-site fabrication with SBKJ machinery directly attacks — moving from imported fabricated stainless duct to local SBAL-V fabrication can reduce installed cost by 15 to 25 percent on the stainless scope.

Seal class — AS 4254 Class C and D

The Australian standard for ductwork construction is AS 4254 Parts 1 and 2, covering low-pressure (Part 1) and medium/high-pressure (Part 2) work. The pressure and seal class for solar manufacturing duct scopes:

• AS 4254 Part 1, Class B seal: module assembly supply, tracker workshop supply and return, warehouse. TDF flange with continuous gasket, sealant on transverse joints only. Leakage 6 L/s per m² at 250 Pa.
• AS 4254 Part 1, Class C seal: cleanroom supply ducts in ISO Class 6 to 8 zones. TDF flange with continuous gasket, sealant on transverse and longitudinal joints. Leakage 2 L/s per m² at 250 Pa.
• AS 4254 Part 2, Class D seal: process exhaust to scrubber, silane and dopant gas cabinet exhaust, perovskite lab hood extract, recycling chemical recovery wet bench extract. Continuous welded longitudinal and transverse seams on stainless ducts. Leakage 0.5 L/s per m² at 500 Pa.
• SMACNA Seal Class A equivalent: ISO Class 5 supply (rare in PV), silane thermal oxidiser inlet duct. Continuous welded seams, pressure-tested at commissioning to 1.5x design pressure for 30 minutes minimum.

The pressure decay test at commissioning is recorded on the AS 4254 certificate that becomes part of the project commissioning evidence pack. Tests that fail are repaired and re-tested before insulation is applied — leak-finding on an insulated duct is a costly exercise.

Fire-rated duct penetrations — AS 1530.4 and AS 1851

Every duct that crosses a fire-rated boundary (typically the cleanroom envelope, the silane bay envelope, and the chemical storage room envelope) requires a fire damper rated to AS 1530.4, installed and tested to AS 1851. The damper is sized for the duct cross-section, drop-tested at commissioning and on an annual interval thereafter, and integrated with the building fire indicator panel. The damper actuator must fail closed on power loss — a fire event coinciding with a power glitch must not leave the damper open.

Smoke spill duct in the cleanroom (per AS 1668.1) is rated to AS 1530.4 for the relevant fire resistance level (FRL) — typically 60/60/60 for the cleanroom envelope and 120/120/120 for the chemical storage and silane bay envelopes. SBKJ fabricates the smoke spill duct in 1.2 to 1.6 mm galvanized or 304L stainless to AS 4254 Class B, with the fire-rating delivered by the insulation system (typically calcium silicate or vermiculite board, certified to AS 1530.4 as a system) wrapped around the SBKJ-fabricated duct.

Specialty gas cylinder room — Zone 1 ATEX, dilution ventilation, leak detection

The specialty gas cylinder room is the single highest-stakes HVAC zone in a silicon PV cell manufacturing plant. The room holds:

• Silane (SiH4) — typical inventory 6 to 12 cylinders, each at 4 to 8 kilograms, total inventory 25 to 100 kilograms.
• Phosphine (PH3) — typically 2 to 4 cylinders.
• Diborane (B2H6) — typically 1 to 2 cylinders.
• Ammonia (NH3) — bulk supply or 6 to 10 cylinders.
• Chlorine (Cl2) — 1 to 4 cylinders for some etch processes.
• NF3 — 2 to 4 cylinders.
• Process nitrogen (N2) — bulk liquid plus distribution.
• Process oxygen (O2) — bulk liquid plus distribution.

The room is classified AS/NZS 60079.10.1 Zone 1 in its entirety, with Ex-d or Ex-e classification on every electrical fitting including light fixtures, motor starters, and emergency stop pushbuttons. The HVAC scope:

• Dilution ventilation at 20 to 30 ACH, sized for the worst-case credible leak from any single cylinder. The dimensioning case is typically a silane cylinder valve failure releasing the cylinder contents over 5 to 15 minutes — at 4 to 8 kilograms of silane this is a substantial release that the dilution ventilation must hold below 25 percent LFL throughout the bay.
• Supply at low level, exhaust at high level — silane and hydrogen are lighter than air and rise; phosphine, diborane and chlorine are heavier than air and pool. The supply diffusers are at low level (300 mm above slab) and the exhaust intakes are at both high level (within 300 mm of the ceiling) and low level (300 mm above slab) to manage both the buoyancy cases.
• 316L stainless duct throughout with welded longitudinal seams to AS 4254 Class D. ATEX or IECEx Zone 1 fan and motor on every exhaust circuit. Earthing of every duct section.
• Multi-gas detection at every gas group — silane (5 ppm TWA), phosphine (0.3 ppm), diborane (0.1 ppm), ammonia (25 ppm), chlorine (0.5 ppm), hydrogen (0.4 percent v/v), with first alarm at half the WES and emergency shutdown at the WES itself. Cross-room interlock to isolate each specific gas at the cylinder manifold on alarm.
• Fire detection by linear heat detection cable along the duct exterior plus flame detector at the ceiling. Fire signature triggers room evacuation, gas isolation and emergency purge mode (5 to 8 times normal exhaust rate, discharging to a dedicated stack with a downstream scrubber).
• Cylinder restraint per AS 4332 with full-height chain restraint on every cylinder, leak-test ports at the manifold, and individual cylinder isolation valves accessible without entering the bay.

The specialty gas room HVAC is typically engineered by a specialist gas room subcontractor working alongside the main mechanical contractor. SBKJ fabricates the 316L stainless duct using the SBAL-V line and the SB-ZF1500 stitchwelder; the Zone 1 fans, dampers, sensors and control panels are sourced from specialist Ex equipment suppliers (Spaccsa, Donaldson Torit, MSA, Crowcon, Honeywell etc.). The cost split is approximately 60 percent specialist gas room equipment and 40 percent SBKJ stainless duct fabrication on this scope.

Process chemical storage — HF, HCl, HNO3, KOH, NaOH

The process chemical storage room holds the bulk acid and base supplies for the wet benches:

• Hydrofluoric acid (HF) — 49 percent technical grade or 5 to 10 percent diluted, typically 1000-litre IBC or smaller drums.
• Hydrochloric acid (HCl) — 32 percent technical grade.
• Nitric acid (HNO3) — 65 to 70 percent technical grade.
• Potassium hydroxide (KOH) — 45 percent solution or solid pellets.
• Sodium hydroxide (NaOH) — solid pellets or 50 percent solution.
• Hydrogen peroxide (H2O2) — 30 to 50 percent.

The room is classified Dangerous Goods Class 8 (corrosive) per AS 1940 storage requirements, with bunded floor sized for 110 percent of the largest single container. The HVAC scope:

• Chemical-resistant FRP or PP storage cabinets with dedicated exhaust at 0.5 m/s minimum face velocity, ducted to the same scrubber system as the wet bench primary extract.
• FRP or PP cabinet exhaust duct to the scrubber (specialist plastic fabricator).
• 316L stainless room general exhaust at 6 to 12 ACH, discharging to a secondary acid scrubber sized for the worst-case bulk release.
• Acid gas detection for HF (1.8 mg/m³ WES), HCl (5 ppm STEL) and NO2 (1 ppm STEL), with first alarm at half the WES.
• Emergency wash facilities per AS 4775 — eye wash and safety shower at every entry/exit, accessible within 10 metres of any chemical handling station.

SBKJ fabricates the 316L stainless general room exhaust and supply ductwork. The FRP/PP cabinet exhaust and the scrubber housings are referred to specialist plastic fabricators.

Compressed gas and bulk gas — AS 4032 medical-style discipline

The compressed and bulk gas distribution to the cell line and the perovskite lab includes process nitrogen, oxygen, argon, helium and process compressed air. Although none of these are toxic or explosive at their typical usage, the supply discipline borrows from AS 4032 medical gas standards because the purity requirements are tight (typical 99.999 percent or better) and oxygen-enriched atmospheres around the bulk LOX storage are a fire hazard.

The HVAC consequence is the LOX storage compound — an outdoor or open-sided enclosure for the cryogenic liquid oxygen tank — which requires natural ventilation per AS 4839 to prevent oxygen enrichment from minor leak. SBKJ does not fabricate the cryogenic storage tank itself but does supply the building eaves louvres, the vapour barrier on the adjacent building wall and any associated ducted intakes.

Worker amenities and office

The amenity and office scope on a PV manufacturing facility is conventional Australian commercial HVAC. AS 1668.2 outside air rates, AS 4254 Class B galvanized duct, conventional ceiling-cassette FCU or VRF systems. SBKJ supplies the full duct scope from the SBAL-V auto duct line with no special configuration. A typical office and amenity package for a 1 GW per year cell factory runs 1,000 to 3,000 square metres of formed duct depending on office occupancy.

Construction sequence and project schedule

The construction sequence for an Australian PV cell + module factory follows a defined order. Reading from the SBKJ machinery delivery and commissioning calendar backward to the project schedule:

1. Shell complete — structural steel, roof, exterior cladding, slab, primary M&E rough-in. Building weather-tight and able to be heated to 18 degrees Celsius. Typical duration 6 to 9 months from groundbreaking.
2. Cleanroom envelope construction — insulated wall panels, sealed floor coatings, ceiling grid, observation windows, airlock doors. The vapour barrier integrity is verified by smoke pencil and pressure decay test before the next step. Typical duration 2 to 4 months.
3. Process MEP rough-in — HVAC ductwork, process gas pipework, electrical, sprinkler, water and DI water services installed inside the cleanroom envelope. This is the largest single trade package. SBKJ machinery typically supplies the on-site or near-site fabrication of stainless duct sections at this stage. Typical duration 4 to 6 months.
4. HVAC commissioning — AHUs, scrubbers and exhaust fans commissioned; ductwork pressure-tested to AS 4254 seal class; cleanroom class verified to ISO 14644-1; gas detection calibrated; fire dampers drop-tested. Typical duration 2 to 4 months.
5. Process equipment installation — wet bench tools, diffusion furnaces, PECVD chambers, screen printers, co-fire furnaces, module assembly equipment installed and commissioned. Typical duration 4 to 8 months.
6. Equipment commissioning — mechanical and electrical commissioning of process equipment, integration with plant utilities, qualification of consumables. Typical duration 2 to 4 months.
7. Cell and module production ramp-up — first article cells and modules, qualification builds to IEC 61215 and IEC 61730, CEC Approved Products List submission, ramp to nameplate capacity. Typical ramp duration 6 to 18 months from first cell to full capacity.

The total project schedule from groundbreaking to nameplate capacity is typically 24 to 36 months for a 1 to 5 GW per year facility, with parallel construction on multiple modules where the project allows. SBKJ machinery delivery is on the critical path for the duct fabrication shop — typical lead time 16 to 22 weeks from order to delivery into Box Hill North or to the project site, plus 2 to 3 weeks for installation and commissioning. The fabrication contractor needs the SBAL-V on site no later than 3 months before duct fabrication starts, which usually means ordering at the same time as the cleanroom envelope contract is awarded.

SBKJ machinery configuration for solar PV facility ductwork

The SBKJ machinery configuration that consistently matches the bill of quantities on Australian solar PV cell, module, perovskite, tracker and recycling project ductwork:

• SBAL-V auto duct line — Models SBAL-V-1250J / SBAL-V-1500J, U-shape automatic duct production line for TDF, angle flange and drive cleat ducts. Handles 0.5 to 1.5 millimetre material thickness, maximum width 1250 / 1500 millimetres, forming speed 16 m/min, overall dimension 14000×2000×1800 / 14000×2200×1800 millimetres, 87 kilowatts power, 16 tons weight, 380V / 50Hz / 3PH. Configured for galvanized and 304L/316L stainless coil with appropriate roller tooling adjustments — typical 15 to 25 percent reduced throughput on stainless. Output 25 to 35 metres per shift on stainless, 40 to 50 metres per shift on galvanized. The dominant machine for both cleanroom supply and general scope.
• SBSF-1525 Pittsburgh lockformer — black steel 0.5 to 2 millimetre thickness, stainless steel 0.5 to 2.5 millimetre thickness, flanging width 75 to 152 millimetres, maximum weight capacity 360 kilograms, 2.5 kilowatts power, 520 kilograms weight, dimension 2200×1100×1240 millimetres, 380V / 50Hz / 3PH. Used for manual fittings, transitions, branches and any geometry that does not pass through the auto line. Stainless-compatible.
• SB-ZF1500 automatic stitchwelder — 0.8 to 3 millimetre thickness, length 100 to 1500 millimetres, diameter Φ150 to Φ1500 millimetres, dimension 2500×1000×2350 millimetres, 380V / 50Hz / 3PH. Used for continuous-weld seal class on 316L stainless scrubber housings, silane exhaust ducts to the thermal oxidiser, and any AS 4254 Class D welded scope. The dominant machine for the welded stainless scope on PV cell projects.
• SBPC1500 plasma cutter — Models SBPC1500×4000 / SBPC1500×6100, processing range 1500×4000 / 1500×6100 millimetres, thickness 0.4 to 8 millimetres, processing speed 7 to 8 m/min, 12 kilowatts power, 2200 / 2700 kilograms weight, dimension 4000×1300×1330 / 5000×1300×1330 millimetres, 380V / 50Hz / 3PH. Used for 316L stainless penetrations, branch fittings, custom transitions and any non-standard geometry. Cuts clean stainless edges without slag deposition that compromises subsequent welding.
• SBLR-600 flexible duct insulation forming — Φ80 to Φ600 millimetre diameter, foil thickness 0.02 to 0.06 millimetres, length up to 36 metres, forming speed 7.6 m/min, 7 kilowatts power, 950 kilograms weight. Used for flexible duct sections in the cleanroom supply where rigid duct cannot route — typical applications include diffuser drop, flex between rigid duct and FFU, and any short flexible coupling at equipment connections. Configured with non-woven fabric, PVC film and aluminium foil.

For a typical 1 GW per year PV cell + module factory of approximately 25,000 to 40,000 square metres of building footprint, the duct scope is 25,000 to 50,000 square metres of formed sheet. Two SBAL-V lines running double shift cover the project schedule with margin for rework and special fabrications. One SBSF-1525 handles all fittings. One SB-ZF1500 handles all stainless welded scope. One SBPC1500 plasma cutter handles all stainless cutting. Total machinery capital is approximately 5 to 8 percent of the total ductwork installed price — a small percentage that returns by 3 to 5 times in fabrication labour savings against imported fabricated duct.

The configuration choices that matter for solar PV work specifically:

• 304L and 316L coil compatibility: rollers and forming dies specified for stainless service to prevent galvanized cross-contamination on duct surfaces. SBKJ supplies the stainless tooling kit at machine delivery.
• TIG welding integration: the SB-ZF1500 stitchwelder configured with argon shielding for 316L stainless service to AS/NZS 1554.6 weld procedure. Welder qualifications to ASME IX or AS/NZS 1554.6.
• Surface protection: protective film on the inside surface during forming, removed at install. Prevents handling marks that compromise cleanability on cleanroom supply ducts.
• Tight tolerance corner geometry: the L-shape and S-shape corners on rectangular cleanroom ducts must match the gasket geometry for AS 4254 Class C sealing. SBAL-V tooling set to tolerance bands consistent with this requirement.
• Earthing tab integration: on stainless duct sections destined for Zone 1 or Zone 2 hazardous areas, the SBAL-V can be configured to punch an earth bonding tab at every transverse joint at a defined offset, simplifying field earthing per AS/NZS 60079.14.

Cost benchmarks and budget guidance

HVAC ductwork including supply, return, process exhaust, scrubber and gas cabinet ventilation typically represents 5 to 9 percent of total capital cost for a greenfield Australian PV cell + module factory of 1 to 5 GW per year. For a project at AUD 500 million to AUD 2.5 billion capital cost — the rough Sun Drive Solar commercial scale-up range based on public ARENA and ASX disclosures — this implies AUD 25 million to AUD 225 million in ductwork material, fabrication and installation.

Within this:

• Cleanroom and PECVD-area stainless and FRP runs: 40 to 55 percent of total ductwork spend.
• Scrubber and gas cabinet exhaust: 15 to 20 percent.
• General manufacturing supply and return (galvanized): 15 to 25 percent.
• Module assembly: 10 to 15 percent.
• Insulation and protection: 8 to 12 percent of installed ductwork cost.

For a perovskite research lab at university scale (50 to 200 m²) the total duct scope is AUD 0.3 million to AUD 1.5 million, dominated by 316L stainless fume hood extract. For a 300 MW per year tracker assembly workshop the total scope is AUD 0.8 million to AUD 2.5 million, mostly galvanized with some welding capture in 304L. For a 5,000 tonne per year PV recycling plant the total scope is AUD 1.5 million to AUD 4.5 million, split between galvanized shred-hall extract and 316L acid recovery scrubber duct.

The material cost component of stainless ductwork is around 40 percent of installed price. Fabrication labour is around 25 percent, installation labour around 20 percent, insulation and accessories around 15 percent. Moving from imported fabricated stainless duct to on-site SBKJ fabrication reduces installed cost by 15 to 25 percent on the stainless scope. Across the Australian solar manufacturing pipeline announced through Solar Sunshot and the broader ARENA pipeline, this is a meaningful capital saving — the SBKJ machinery payback is typically 12 to 24 months from first production on a 1 GW per year factory scope.

Validation, commissioning and the Clean Energy Council interface

HVAC commissioning on a PV cell + module factory is rigorous but less intense than a battery gigafactory or a leading-edge semiconductor fab. The typical validation suite:

• AS 4254 pressure leakage testing on completed duct sections before insulation. Class B, C or D verification at 1.5 times design static pressure. Sections that fail are repaired and re-tested.
• AS 1668.2 ventilation balancing by anemometric supply and exhaust measurement at every diffuser and intake. Verified to plus or minus 10 percent of design.
• ISO 14644-1 particle counting at every cleanroom grid point under operational, at-rest and as-built conditions.
• Pressure cascade verification at every airlock with all doors closed and worst-case door-open scenarios. Recorded with calibrated micromanometer at 0.1 Pa resolution.
• HEPA challenge testing per IEST-RP-CC034 with PAO aerosol, 99.97 percent (H13) or 99.995 percent (H14) retention verified at every terminal filter housing.
• Gas detection calibration with reference gases at multiple concentrations — silane, phosphine, diborane, ammonia, chlorine, HF, hydrogen.
• AS/NZS 60079.17 hazardous area certificate covering Ex equipment installation, earthing, and inspection regime.
• AS 1851 fire damper drop tests on every fire damper with command from BMS.
• Acoustic verification at the worst-case occupational receiver — NC-45 or 70 dBA at the cleanroom operator station, NC-60 at the gas cabinet bay.

For Clean Energy Council Approved Products List submission the HVAC commissioning evidence supports the IEC 61730 (PV module safety) and IEC 61215 (PV module performance) testing that is conducted in the on-site or third-party qualification lab. The CEC submission package includes ductwork as-built drawings, AS 4254 certificates, AS 1668.2 balancing reports and AS/NZS 60079.17 certificates as part of the production environment evidence.

For Solar Sunshot funding milestones the HVAC commissioning sign-off is a defined gate in the ARENA milestone schedule. ARENA's program documentation references the standards above and requires evidence of practical completion to those standards before the production credit phase commences.

Energy efficiency — PID, IEC 62804 and the heat recovery story

PV cell manufacturing is energy-intensive but less so than battery gigafactory or semiconductor manufacturing — typical electricity demand for a 1 GW per year cell line is in the 30 to 60 megawatt range. HVAC consumes 20 to 30 percent of total facility energy in a typical PV cell + module plant. The leverage points:

• Heat recovery from PECVD chamber pump exhaust — the silane PECVD chambers run at 350 to 450 degrees Celsius and the pump exhaust is at 80 to 120 degrees Celsius after the dilution. Recovered into plant preheat duty or domestic hot water through a stainless heat exchanger.
• Heat recovery from co-fire furnace exhaust — 700 to 900 degrees Celsius furnace exhaust, post-RTO at 200 to 300 degrees Celsius. Substantial sensible heat recoverable through a glycol run-around coil to preheat outdoor air entering the cleanroom AHUs.
• Variable speed drives on every fan and pump.
• Tight ductwork (AS 4254 Class C / D) — cuts re-conditioning load proportionally to the leakage rate avoided.
• Free cooling in winter for module assembly heat rejection — most Australian PV manufacturing sites can run module assembly cooling on outside air alone for 4 to 6 months of the year.

The other PV-specific energy consideration is module quality. Modules that fail the IEC 62804 potential-induced degradation (PID) test in the QA lab are scrapped or downgraded — and the test itself runs at 60 degrees Celsius and 85 percent relative humidity in an environmental chamber that draws meaningful HVAC load. The QA lab HVAC scope is small in absolute terms but disproportionately energy-intensive per square metre.

Construction risk, lead time and supply chain

Australian PV manufacturing projects have specific construction and supply chain considerations:

• Stainless steel coil lead time: 316L coil at PV manufacturing volumes (tens to hundreds of tonnes) typically commands 12 to 16 week lead times in 2026 Australian market via Bluescope, OneSteel or direct import. The order should be placed at the same time as the cleanroom envelope contract is awarded.
• SBKJ machinery lead time: SBAL-V configured for stainless and galvanized service typically delivers within 16 to 22 weeks of order from the SBKJ office in Box Hill North. SB-ZF1500 stitchwelder 12 to 14 weeks. SBPC1500 plasma cutter 10 to 14 weeks. SBSF-1525 lockformer 8 to 10 weeks. SBLR-600 flexible insulation 10 to 12 weeks.
• FRP/PP duct lead time: 8 to 14 weeks from specialist plastic fabricators (Ducon Plastics, Trans-Plastic and similar). Coordinate at the same time as the scrubber package order.
• Scrubber housing fabrication: 316L stainless via SBKJ-supplied fabricator network, 12 to 16 weeks from order to delivery.
• Gas detection equipment: ATEX or IECEx certified multi-gas detectors at 8 to 14 weeks lead time. Specialist suppliers (Honeywell, Crowcon, MSA) maintain Australian stock for common configurations.
• Spark-resistant fans: ATEX or IECEx Zone 1 rated, typically 12 to 20 weeks from Australian and European specialist suppliers.
• HEPA filtration: H13 and H14 filter housings 8 to 12 weeks.
• Fire dampers to AS 1530.4: 6 to 10 weeks.
• Trades availability: Australian HVAC contractors with cleanroom and hazardous-area experience are in finite supply. Major PV manufacturing projects typically engage Stowe Australia, A.G. Coombs, Fredon Mechanical or similar tier-1 mechanical contractors, with subcontracted ductwork fabrication packages awarded to specialist shops running SBKJ machinery.

How HVAC ductwork sits in the broader cleanroom and energy-transition industries

Solar PV manufacturing HVAC shares engineering DNA with several adjacent industries:

• Semiconductor fabs — see our semiconductor fab HVAC duct guide. PV cell manufacturing derives its silane and dopant chemistry directly from semiconductor practice but runs at much looser cleanroom class (ISO 6/7 vs ISO 3/4) and larger feature size.
• Battery gigafactory — see our battery gigafactory HVAC duct guide. Battery dry rooms are tighter on dewpoint and ACH but neither industry overlaps on hazardous gas — battery is NMP solvent and electrolyte vapour, PV is silane and dopant gases.
• Hydrogen production — see our hydrogen production HVAC duct guide. The AS/NZS 60079 Zone 1/2 framework and the spark-resistant fan and Ex motor specification apply identically to silane PECVD and to hydrogen electrolyser halls.
• Solar farm BESS inverter station — see our solar farm BESS inverter HVAC duct guide. The downstream utility-scale PV deployment that consumes the modules manufactured upstream, with conventional galvanized HVAC scope.
• Glass and mirror manufacturing — see our glass and mirror manufacturing HVAC duct guide. The front glass component of every PV module originates in a float glass plant.
• Cleanroom duct manufacturing — see our cleanroom duct manufacturing guide for the cross-cutting cleanroom HVAC requirements.

An MEP contractor or HVAC specifier coming from any of these adjacent fields can apply most of their experience to PV manufacturing work, but must specifically learn the cleanroom class allocation (looser than semiconductor, similar to pharmaceutical Grade C), the hazardous gas dilution discipline (silane and dopants drive Zone 1 requirements), and the wet bench chemistry (HF demands FRP and 316L).

How SBKJ scores against solar PV manufacturing requirements

The SBKJ engineering and supply offer for Australian solar PV cell + module, perovskite, tracker and recycling project ductwork:

• Machinery range: SBAL-V (rectangular auto duct), SBSF-1525 (Pittsburgh lockformer), SB-ZF1500 (stitchwelder), SBPC1500 (plasma cutter), SBLR-600 (flexible duct) — all configurable for 304L and 316L stainless service. See the full machine catalogue.
• Cleanroom track record: SBKJ machines installed at pharmaceutical, semiconductor, battery and cleanroom fabricators across 100+ countries, with certifications and references available on request.
• Stainless configuration expertise: SBKJ engineers configure roller tooling, plasma cutters, welding stations and surface protection for stainless service as standard, not as an exception.
• Australian base: Box Hill North, Victoria headquarters provides English-language engineering, after-sales support and machinery procurement for Australian and Pacific projects without time-zone friction. ARBS 2026 exhibitor.
• Project schedule support: machinery delivery 16 to 22 week lead time, with full operator training and commissioning by SBKJ engineers on site.
• Spare parts continuity: 10-year minimum parts support commitment in writing, in line with the typical 20-year PV manufacturing operational horizon.
• Industry referrals: for the FRP/PP fluoride extract scope outside SBKJ's catalogue, SBKJ maintains active referral relationships with Australian specialist plastic ductwork fabricators.
• CEC and Solar Sunshot familiarity: SBKJ's commissioning documentation templates are configured for the Clean Energy Council Approved Products List submission package and the ARENA Solar Sunshot funding milestone gates.

Discuss your solar PV manufacturing ductwork project with SBKJ →

FAQ

What HVAC class applies to a PV cell manufacturing cleanroom?

Mainstream silicon PV cell manufacturing typically runs ISO 14644-1 Class 6 to Class 7 in the wet bench, diffusion and PECVD bays, with Class 5 reserved only for the most particle-sensitive metrology and a few high-efficiency HJT or TOPCon stations. This is two to three classes looser than a leading-edge logic semiconductor fab. The ductwork implication is that 304L or 316L stainless on supply ducts upstream of the terminal HEPA H13/H14 filters is sufficient, with 2B mill finish acceptable on interior surfaces — full electropolishing is rarely specified outside the metrology and ALD stations.

Why does silane SiH4 deposition demand spark-resistant fans?

Silane is pyrophoric — it auto-ignites in air at concentrations above approximately 1 percent without an ignition source. Safe Work Australia sets the silane WES at 5 ppm TWA. Any silane PECVD bay is classified AS/NZS 60079.10.1 Zone 1 inside the gas cabinet and Zone 2 in the surrounding bay. Exhaust fans must be ATEX or IECEx Zone 1 rated with non-sparking aluminium impellers, motors must be Ex-d flameproof, and the duct itself must be earthed to the building equipotential reference. Discharge is via thermal oxidiser to silicon dioxide and water.

What duct material survives hydrofluoric acid in PV wafer texturing?

Hydrofluoric acid attacks every common metallic duct material — galvanized, aluminium, 304L and 316L stainless will all fail on the primary fluoride extract within months. The standard is FRP with vinyl-ester or furan resin, or polypropylene (PP), fabricated by a specialist plastic fabricator (refer outside SBKJ catalogue). SBKJ supplies the 316L stainless scrubber housing and the post-scrubber discharge duct.

What ventilation rate does a PV cell PECVD silane bay need?

12 to 25 air changes per hour of total mechanical ventilation, sized to dilute the worst-case credible silane leak below 25 percent of the LFL (treated conservatively as 0.25 percent v/v). For a typical 100 to 300 sccm leak from a gas cabinet manifold, this translates to 6,000 to 20,000 cubic metres per hour of dilution per cabinet.

Is solar tracker assembly a major HVAC duct scope?

Solar tracker mechanical assembly (Nextracker, Array Technologies, PV Hardware, 5B Maverick, Sun Drive) is a workshop-style operation with conventional galvanized supply and return plus welding fume capture at every weld station and paint booth bays. A typical 300 MW per year tracker assembly shop runs 4,000 to 8,000 square metres of formed duct, fabricated entirely on the SBAL-V auto duct line and the SBSF-1525 lockformer.

What HVAC scope does a PV recycling plant need?

PV recycling — Reclaim PV Recycling in Adelaide, Lotus Energy ANU in Canberra — combines mechanical processing (frame removal, glass shredding, EVA delamination) and chemical recovery (silver and silicon extraction). The duct scope spans general shop supply and return, dedicated HEPA-filtered dust extraction on the shredder (lead and tin in older modules), organic vapour extract on the EVA thermal step, and 316L stainless acid scrubber duct on the chemical recovery wet bench.

Why is perovskite cell research lab HVAC different from silicon PV cell HVAC?

Perovskite cells use methylammonium iodide and lead iodide as the active layer precursors. Lead is the controlling exposure — Safe Work Australia WES is 0.05 mg/m³ TWA. The fabrication chamber and spin coater enclosure require dedicated local exhaust with HEPA-grade aerosol filtration before discharge, lead-decontamination-rated flooring, and personnel exposure monitoring. The organic solvent loads — DMF, DMSO, chlorobenzene, IPA — add a flammable mixture demand that drives AS/NZS 60079 Zone 2 classification in the synthesis fume hoods.

What is the typical duct cost as a percentage of a PV cell manufacturing build?

5 to 9 percent of total facility capital cost for a greenfield 1 to 5 GW per year cell + module factory. Within this, cleanroom and PECVD-area stainless and FRP runs account for 40 to 55 percent, scrubber and gas cabinet ducts 15 to 20 percent, general manufacturing 15 to 25 percent, module assembly 10 to 15 percent. For a 1 GW per year cell factory at AUD 500 million to 1 billion capital, the duct scope is AUD 25 to 90 million.