Insights · Industry HVAC Ductwork
A senior-engineer reference for HVAC ductwork in Australian window, door, aluminium joinery, glass processing and architectural curtain wall manufacturing — anodising acid exhaust, powder-coat cure ovens, glass cutting silica capture, IGU assembly clean rooms and curtain wall fabrication bays, mapped to AS 2047, AS 1288, AS/NZS 1668.2 and AWA certification.
A residential window factory and a commercial curtain wall workshop look superficially similar. Both extrude or cut aluminium profiles, both process glass, both assemble glazed units, both ship a finished envelope product. Both have a few hundred staff, a long bay, an overhead crane, a paint or coating area, a glass-cut bench and a packing dock. From a building services perspective they look like ordinary medium-light industrial sheds.
They are not. Australian fenestration manufacturing — the integrated category that covers windows, external glazed doors, aluminium joinery, IGU assembly, glass processing and architectural curtain wall fabrication — is one of the most diverse process-air environments in the building-products supply chain. A single factory floor will often house six or seven distinct emission profiles within sight of each other, each with its own velocity, temperature, chemistry and material specification. Get one wrong and the consequences range from premature duct failure to AWA audit non-conformance to NCC Section J performance gaps on every window that leaves the dock.
This guide is the reference our engineers use when we walk an Australian window, door or curtain wall fabricator through a workshop ventilation redesign. It is written for the plant engineer, the principal architect's specifier and the operations director who has been asked why the duct above the anodising line is sagging after 18 months. It assumes you already know how to read a P&ID and a duct schedule; it focuses on the decisions that distinguish a fenestration HVAC design from a generic light-industrial ventilation scheme.
The Australian fenestration industry is dominated by a relatively small number of large fabricators — G.James Glass and Aluminium across both residential and commercial scopes, Capral Aluminium on extrusion, Stegbar inside the Jeld-Wen Australia group, Wideline Windows on the eastern seaboard residential market, Trend Windows & Doors as a long-running residential fabricator, Hume Doors & Timber and Corinthian Doors on the door side, Bradnam's Windows & Doors out of Queensland, Crystal Windows Australia in the residential mid-tier, Lidco out of Western Australia, Allkind Joinery on the architectural joinery side, AluK Australia and Reynaers Australia as Belgian system-house representatives serving the commercial market, and Lifestyle Windows from Tasmania. The architectural curtain wall premium tier is led by YKK AP Australia, Permasteelisa Australia, Tilt Industrial on industrial sliding, Apex Architectural on commercial systems and Architectural Glass and Cladding (AGC) on cladded façades. Glass processing in Australia runs through Viridian Glass (part of CSR), G.James, and Pilkington Australia, with extrusion supplied by Capral, Bradnam's Aluminium and AluK. Whether you sit in a residential fabricator running domestic-class N3 wind-rated windows or in a curtain wall premium-tier shop running 12-metre unitised mullions for a high-rise façade, the underlying ductwork principles are the same — but the consequences of getting them wrong scale with the value of the product passing under the duct.
Australian fenestration is one of the more heavily standardised manufacturing categories in the country. Five documents do most of the work, and a sixth — the AWA certification scheme — closes the loop by binding fabricator practice to the standards.
AS 2047 is the keystone fabrication standard. It sets the rules for window and external door performance testing, labelling, glazing methods and quality control. A window labelled AS 2047 must have been fabricated in an environment that supports the labelled performance — frame squareness, sealant cure, IGU integrity, hardware function and weather-seal compression are all sensitive to the factory environment. The standard does not mandate specific HVAC parameters, but it does require that the fabricator demonstrate a controlled, repeatable manufacturing process. In practice that means a stable temperature and humidity profile in the IGU sealing room, a clean and dry environment for sealant application, and a contamination-free finishing line.
AS 1288 governs glass selection — type, thickness, treatment — and installation. It does not directly regulate the factory environment, but it interacts with HVAC design through IGU performance. An insulated glass unit fabricated in a humid environment with dust-contaminated spacer adhesive will fail the in-service moisture-ingress test that AS 1288 references. The HVAC consequence is that the IGU assembly room is the most sensitive space in the factory and must be designed to clean-room standards.
AS 4055 sets the residential wind classification system — N1, N2, N3, N4, N5, N6 in non-cyclonic regions and C1, C2, C3, C4 in cyclonic regions. The classification drives the structural design of the window unit and indirectly drives the manufacturing tolerances the factory must achieve. A residential window factory producing N3-rated windows for Sydney suburbs has very different tolerance requirements from one producing C2-rated windows for Townsville. Both must be supported by an HVAC design that delivers consistent dimensional stability — a window assembled at 35 degrees Celsius and shipped to a 5 degree Celsius site will not seat correctly if the frame thermal expansion was not controlled at assembly.
AS 1170.2 is the structural wind-action standard for commercial buildings. It governs the design wind pressure that a commercial window or curtain wall must resist. The HVAC implication is on the testing rig, not the production floor — a commercial fabricator producing AS 1170.2-compliant curtain wall units must support a chamber-test facility for serviceability and ultimate-state pressure cycling, and the chamber test room itself has dedicated supply and exhaust requirements distinct from the main factory floor.
AS 1170.4 covers earthquake loads on building structures and components. Commercial curtain wall systems must be designed to accommodate inter-storey drift, and the fabricator's test rig must support a racking-and-drift cyclic test. As with wind testing, the implication on HVAC is the test laboratory space — temperature-controlled, low-vibration, with a dedicated ventilation envelope.
AS/NZS 1668.2 is the primary mechanical-ventilation code. For an aluminium and glass factory it sets the minimum outside-air rates for office and amenity zones and refers the process-air design to dilution and capture principles drawn from the contaminant inventory. The standard does not give a one-line answer for a window factory floor. The practical engineering baseline is six to eight air changes per hour of general dilution, supplemented by local-exhaust capture at every emission source.
The Australian Window Association runs a third-party certification scheme that audits fabricator compliance with AS 2047. A certified fabricator must maintain documented process controls — including the manufacturing environment — and the AWA auditor will spot-check that the IGU room is dry, the anodising line is exhausted to scrubber and the powder-coat oven is operating within its stated cure window. AWA certification is increasingly a commercial gate for tender qualification on government and large residential projects, which means the HVAC design of the factory effectively becomes part of the brand promise.
NCC Volume One Section J sets the energy-efficiency requirements for commercial buildings, including window U-value and Solar Heat Gain Coefficient (SHGC). The Section J calculation submitted with a building approval references a specific window assembly with a labelled U-value and SHGC. The fabricator has to produce that exact assembly. If the factory environment causes the IGU to drift — moisture ingress, gas fill loss, spacer-adhesive failure — the as-built window will underperform the Section J calculation, and the building will fail the energy-efficiency verification on completion. The HVAC design of the IGU room is therefore not a workplace amenity question; it is part of the regulatory chain that delivers Section J compliance to the end building.
Before sizing any duct, the engineer must understand what comes off each station. Below is the emission inventory for a typical mid-scale Australian aluminium-window and IGU fabricator running both residential and light commercial product.
The extrusion mill ships profiles to the fabricator already extruded. The fabricator's first step is cleaning, anodising, powder coating or a combination. The cleaning bath strips extrusion lubricant and oxidation; the anodising line builds a controlled aluminium-oxide layer; the powder-coat line applies a coloured polymer finish over the aluminium-oxide layer or over a chromate-conversion or chrome-free pretreatment. Each of these steps has a distinctive exhaust requirement.
A typical aluminium anodising line has six to ten process tanks. The sequence is degrease, rinse, caustic etch (sodium hydroxide), rinse, deoxidiser, rinse, anodise (sulfuric acid), rinse, colour (if dyed), seal, rinse, dry. Each chemical tank emits a process-specific exhaust:
The combined anodising line exhaust is a wet acid mist with chloride ions, and this is the duct specification that catches more first-time fabricators out than any other. Galvanised duct fails in months — the zinc coating sheds under acid attack, the exposed mild steel pits and rusts, and the duct sheds debris back into the workspace. SBKJ specifies 316L stainless from hood to scrubber, because the molybdenum content in 316L resists chloride pitting where 304 stainless will fail. The duct must be all-welded — flanged joints with rubber gaskets leak acid mist within the first year. SBKJ's TIG seam welder is the standard fabrication tool for these duct sections.
The powder-coat line typically runs as electrostatic spray booth, pre-cure flash zone, cure oven, cooldown, off-load. The cure oven is the highest-temperature continuous-operation element in the factory. Oven exhaust is 180 to 200 degrees Celsius continuous, carrying low concentrations of VOCs from the curing polymer and partially cured powder particulates. The exhaust ductwork must be 316L stainless from the oven flange to the cooldown header — galvanised loses zinc-coating integrity above 200 degrees Celsius, mild steel rusts internally as the duct cools and condensate forms. Once the exhaust drops below 100 degrees Celsius, the duct can transition to aluminised mild steel or 304 stainless for economy. TIG seam welding is required throughout — riveted-and-sealed joints leak after 50 thermal cycles, which is roughly 30 working days.
The spray booth itself is a controlled-environment enclosure with cross-draught or down-draught airflow. Face velocity at the operator plane is 0.4 to 0.6 m/s — high enough to capture overspray, low enough not to disturb the electrostatic charge holding powder to the part. The booth recirculates through a recovery cyclone, which collects and returns oversprayed powder to the supply hopper for reuse. Downstream of the cyclone is a HEPA filter bank to scrub residual fines before discharge. The booth make-up air must be tempered to 18 to 22 degrees Celsius and 50 to 60 percent relative humidity — powder fluidisation is sensitive to humidity, and a booth running outside this window suffers blocked guns, uneven coating thickness and high reject rates.
Glass processing inside a window or curtain wall factory typically includes float-glass cutting, edge grinding, edge polishing, CNC drilling for hardware, and tempering or laminating. Cutting itself is largely score-and-snap and produces minimal dust; grinding, polishing and drilling are the heavy dust sources. The dust is respirable crystalline silica, which Safe Work Australia regulates under the workplace exposure standard for respirable crystalline silica. Local-exhaust capture velocity is 1.0 to 1.5 m/s at the source, transport velocity in the duct 18 to 20 m/s to keep the silica suspended, downstream HEPA filtration with continuous differential-pressure monitoring. The duct must be heavy-gauge — minimum 1.2 mm galvanised — to resist abrasion from the silica stream over a 20-year service life. Spiral round duct fabricated on an SBTF-1602 tubeformer with 1.2 mm coil is the standard SBKJ recommendation for these high-abrasion transport duct sections.
IGU assembly is functionally a clean-room operation. Two or three glass panes are separated by a spacer bar filled with desiccant, the cavity is gas-flushed with argon or krypton, and the perimeter is sealed with a primary butyl seal and a secondary polysulphide, polyurethane or silicone seal. The unit is then aged for hours to days before glazing. The integrity of the seal — and therefore the long-term performance of the unit — depends on three factory environment parameters: room dust, room humidity and room temperature. Dust contaminates the spacer adhesive; humidity saturates the desiccant before the seal is closed; temperature drift changes the sealant cure rate.
SBKJ specifies the IGU room as HEPA-filtered supply at 12 to 18 air changes per hour, room dew point below 10 degrees Celsius, slight positive pressure relative to the surrounding factory (5 to 15 Pa), dedicated low-velocity diffusers above the sealing tables and a clean-air return path back to the HEPA bank. The room must include dedicated argon and krypton gas supply lines with gas-leak monitors interlocked to room exhaust — heavier-than-air gas releases can displace breathable air in low corners.
Aluminium extrusion is cut to length on cold saws and then machined for hardware on CNC routers and copy routers. Both produce dry aluminium swarf and chip — non-toxic and non-respirable in normal handling, but a fire and dust-explosion risk if allowed to accumulate. Local-exhaust capture at saw and CNC stations transports the chip to a cyclone separator for collection and recycling. Transport velocity in the chip duct is 18 to 22 m/s. The chip duct must be earthed and bonded to dissipate electrostatic charge — aluminium dust is a known explosion hazard at high concentrations.
Hardware install (hinges, locks, handles, weatherseals) is ambient assembly work. No process exhaust required beyond general dilution. The work bench area benefits from comfort ventilation at 22 to 24 degrees Celsius, 50 to 60 percent relative humidity, and acoustic NC-40 to support the fine motor work and quality inspection.
The single decision that drives the long-run reliability of an Australian fenestration factory ductwork system is duct material selection per zone. Below is the SBKJ engineering reference table — the same we use when scoping a fabrication-cell duct package.
The wet acid mist with chloride ions punishes any material short of 316L. Galvanised duct fails within months. 304 stainless lasts longer but eventually suffers chloride pitting. PVC and FRP are alternatives but have temperature and pressure limits that complicate the design at the scrubber inlet. 316L stainless with TIG-welded seams and welded flanges is the conservative engineering specification for the duct run from hood to scrubber. SBKJ's SBAL-V plasma cutting line cuts 316L plate to size; the spiral tubeformer SBTF-1602 forms the round-duct cross-section; the TIG seam welder closes the longitudinal and circumferential seams.
Continuous 180 to 200 degrees Celsius exhaust exceeds the safe operating range of galvanised coating, and the cooldown condensate corrodes uncoated mild steel. 316L stainless is the standard. Once the exhaust falls below 100 degrees Celsius (typically after a cooldown header or a dilution tee), the duct can transition to aluminised mild steel or 304 stainless. Flanges must be TIG seam welded — bolted flanges with rubber gaskets fail after 50 thermal cycles as the gaskets harden and crack.
The booth supply and recirculation duct handles tempered make-up air and overspray-laden return air. Both are ambient temperature, dry and chemically benign once filtered. Standard galvanised G300 with Z275 coating is the cost-effective specification. The recirculation duct should be designed for periodic cleaning access — powder accumulates in long horizontal runs and must be cleared on a documented schedule.
The transport duct from glass cutting and grinding stations to the dust collector is abrasive service. Minimum 1.2 mm galvanised, ideally 1.5 mm in long runs and at elbows. Spiral round duct outperforms rectangular for both abrasion resistance and transport efficiency. SBTF-1602 spiral tubeformer with 1.2 mm coil produces the standard cross-section. Long-radius elbows preferred over short-radius — short-radius elbows wear through in 5 to 7 years on abrasive duty.
The clean-room supply and return duct must be airtight to maintain pressure differential and avoid drawing factory contamination into the clean envelope. Standard galvanised G300, with seams sealed and the assembly pressure-tested to SMACNA seal class A. Interior surfaces should be smooth and free of weld spatter — the duct should not become a particle source. SBKJ's standard fabrication practice for clean-room duct is roll-formed Pittsburgh seam with bead-sealant and pressure-tested at 250 Pa for ten minutes.
The bulk of the factory ductwork — supply diffusers, return grilles, distribution headers — is conventional galvanised. G300 Z275 is the standard. Rectangular for low-velocity supply and return, spiral round for high-velocity transport. Coordinated with overhead crane clearance and process equipment access.
Commercial curtain wall and shopfront fabrication includes spot welding, MIG and TIG welding for steel sub-frames and brackets. Fume capture at the source via swing-arm hoods or fixed slots, transported through galvanised duct to a downstream filter (HEPA or electrostatic precipitator). Capture velocity 0.5 m/s at 250 mm from the arc. Transport velocity 10 to 14 m/s.
The single most expensive design mistake we see in Australian aluminium fabrication plants is galvanised duct above or near the anodising line. It is worth understanding why this fails, because the failure mode is not obvious and the financial consequence is hidden in maintenance budgets across a 10-year horizon.
Galvanised duct is mild steel with a sacrificial zinc coating, typically applied at G300 Z275 (300 MPa minimum yield, 275 g/m² zinc on both sides combined). The zinc protects the steel by being preferentially consumed in mild atmospheric corrosion — over a 25-year service life in an ordinary indoor environment, the zinc is gradually consumed and the steel substrate remains intact.
The anodising line produces a wet exhaust at near-ambient temperature, saturated with water vapour and carrying entrained droplets of sulfuric acid, sodium hydroxide neutralised products and — critically — chloride ions. The chloride comes from the make-up water (in many Australian municipal supplies), from chloride additives in the deoxidiser tank chemistry, and from any acidic spray rinse that uses tap water. The chloride content is low — often only 10 to 50 ppm in the entrained mist — but it is sufficient to attack zinc galvanising at an accelerated rate.
The failure sequence is:
The unplanned-replacement cost of an anodising line duct system at year three is typically three to five times the additional cost of specifying 316L stainless on day one. The 316L specification adds roughly 80 to 150 percent to the duct material cost on the affected sections only — usually 15 to 25 percent of the total factory duct material spend. Over a 20-year horizon, the lifecycle cost difference is overwhelmingly in favour of 316L. We have seen fabricators replace galvanised anodising duct twice in eight years before finally specifying 316L, having paid for the stainless three times over in scrap, downtime and remediation.
The powder-coat cure oven is the second-most-misunderstood duct specification in an Australian fenestration plant. The failure modes are similar in pattern to the anodising line but driven by temperature rather than chemistry.
Cure oven exhaust runs 180 to 200 degrees Celsius continuous. The exhaust composition is mostly clean air with low concentrations of VOCs released from the curing polymer (typically polyester or polyester-TGIC, increasingly polyester-HAA) and trace partially cured powder particulates that escaped the cure cycle. The chemistry is not aggressive — the temperature is the problem.
Galvanised G300 Z275 has a documented zinc-coating service ceiling around 200 degrees Celsius. Above that, the zinc oxidises rapidly and loses sacrificial protection. Below that but in cycling service, the zinc-coating integrity is acceptable but the duct experiences thermal expansion and contraction every cycle. The expansion of mild steel is roughly 11 microns per metre per degree Celsius. A 10-metre run of duct cycling from 25 to 200 degrees Celsius expands and contracts by about 19 mm. If the duct is rigidly anchored without expansion joints, the cycling stress concentrates at the weakest point — typically a flanged joint with a gasket.
Riveted-and-sealed flanged joints fail at 30 to 50 thermal cycles. The gasket hardens, cracks and falls out. The rivets work loose. Within 30 working days of operation, the joint leaks hot exhaust into the ceiling space. The leak is invisible until the surrounding structure shows heat damage — discoloured ceiling tiles, melted cable insulation, blistered roof-deck paint.
The engineering specification for the powder-coat cure oven exhaust is therefore:
The SBTF-1602 spiral tubeformer running 1.6 mm 316L coil produces the round-duct cross-section. The TIG seam welder closes the seams. The combined fabrication cell — plasma cutter for flange and transition pieces, spiral tubeformer for the long round runs, TIG seam welder for the closures — is the standard SBKJ workshop kit for fenestration-plant powder-coat exhaust ductwork.
An insulated glass unit is a deceptively simple product. Two or three panes of glass, a perimeter spacer bar containing desiccant, a cavity filled with argon or krypton, two layers of sealant around the perimeter. Yet the cumulative defect rate of IGU production is the single largest quality-control challenge in modern fenestration manufacturing — and the factory environment is the dominant cause.
The performance specification a fabricator must meet is AS 1288 plus the manufacturer's own warranty (typically 10 years against fogging, gas-fill loss or seal failure). The failure modes are:
The HVAC specification that supports a reliable IGU operation is:
The duct material for the IGU room is conventional galvanised G300, but the fabrication standard is higher than for general factory ductwork. All seams sealed, all joints pressure-tested to SMACNA seal class A, interior surfaces smooth and free of weld spatter or roll marks that can shed particles. Diffuser interiors should be wiped clean and sealed before fitting to ensure they do not become a particle source on first start-up.
The premium tier of Australian fenestration — YKK AP Australia, Permasteelisa Australia, Apex Architectural, Tilt Industrial on industrial sliding doors, Architectural Glass and Cladding on cladded façades — fabricates large-format unitised curtain wall, shopfront systems, structural glazing and bespoke architectural assemblies. The workshop environment for this work differs from a residential window plant in scale and acoustics, not in chemistry.
A typical curtain wall fabrication bay is 30 to 50 metres wide, 60 to 120 metres long, with 8 to 14 metre clear ceiling height. Overhead cranes traverse the bay to handle unit sub-assemblies up to 12 metres long and several hundred kilograms. The bay houses cutting saws for mullion and transom extrusions, CNC machining stations for hardware preparation, assembly tables for unit sub-assemblies, structural sealant application stations, glass insertion and glazing stations, and finished-unit staging for QA inspection before despatch.
The HVAC design baseline for a curtain wall fabrication bay is:
The duct material for the bay is conventional galvanised throughout. The complexity is in the layout — long runs, large branch fittings, integration with overhead crane clearance, and seismic-rated supports per AS 1170.4 for the heavier supply and exhaust mains.
An aluminium and glass fabrication factory is intrinsically noisy. Cold saws cutting extrusion, CNC routers machining hardware preparations, plasma cutters processing steel sub-frames in commercial bays, glass cutting tables, edge grinders, hammer drills installing weatherseals — the cumulative ambient noise on a busy fabrication floor is typically 80 to 88 dBA without ventilation noise added.
The HVAC system contribution to the overall noise budget should be at NC-50 or below across the open floor, dropping to NC-40 in QA inspection, shop-drawing review and engineering-office zones. The dominant HVAC noise sources are:
The acoustic design is rarely the limiting constraint in a fenestration plant — process noise dominates — but it is the differentiator between a workshop where supervisors can hold a normal conversation on the floor and one where everyone shouts. The premium-tier curtain wall fabricators (Permasteelisa, YKK AP, Apex) typically design to a 5 dB tighter budget than the residential fabricators, because their assembly work is more attention-intensive and their staff retention is sensitive to workplace conditions.
The duct package for an Australian fenestration plant — even a mid-scale residential fabricator — is one of the more diverse jobs in industrial ductwork. The fabrication shop must produce:
The SBKJ workshop configuration for this scope of work is:
The SBAL-V plasma cutting line is the entry point for both stainless and galvanised plate fabrication. It cuts 316L plate up to 6 mm thickness, 304 plate up to 6 mm, and galvanised G300 from 0.6 to 3.0 mm. Plasma-cut edges are clean and weld-ready. The line handles flanges, transition pieces, dampers and any complex profile that cannot be roll-formed. The SBAL-V's CNC import accepts duct-detailing software output directly, which means the same shop-floor file flows from design through nesting through cut without manual translation.
The SBTF-1602 spiral tubeformer fabricates round duct from coil. With a 1.6 mm capacity it handles the full range of duct gauges used in a fenestration plant — 0.6 mm light-duty supply, 0.8 to 1.0 mm general transport, 1.2 mm abrasion-resistance for silica transport, 1.6 mm 316L for high-temperature exhaust. Round duct outperforms rectangular for high-velocity transport (lower pressure drop per unit material weight, less surface area for deposit accumulation, better abrasion characteristics in dust-laden service). The SBTF-1602 produces long continuous runs that minimise field joints and reduce leakage points.
The TIG seam welder closes longitudinal and circumferential seams on stainless duct sections. TIG (tungsten inert gas) welding produces a clean, defect-free seam that resists chloride pitting and high-temperature degradation. The welder runs argon shielding gas and either DC straight polarity (for stainless) or AC (for aluminium duct on the rare specifications that call for it). Pulse TIG modes are used on thin-gauge 316L to control heat input and avoid distortion. The TIG seam weld is the single most important capability separating a fenestration-grade duct shop from a generic sheet-metal shop.
The SBKJ fabrication cell — SBAL-V plasma cutter, SBTF-1602 spiral tubeformer, TIG seam welder, plus auxiliary brake press, bead roller and Pittsburgh seamer — sits on a 30 by 12 metre footprint with overhead lift and material flow from coil store through cut to weld to QA. A two-shift operation produces enough duct for a 5,000 m² fenestration plant in approximately three to four months of dedicated production. For larger projects — a Permasteelisa-scale or YKK AP-scale 20,000 m² facility — the typical SBKJ engagement is six to nine months with two parallel cells.
The Australian fenestration market is dominated by a relatively small number of large fabricators, each with its own profile. Understanding which segment each operator serves helps the engineer scope an HVAC design that fits the operating model.
G.James Glass and Aluminium — the largest integrated residential and commercial fenestration manufacturer in Australia. G.James operates its own glass processing, aluminium extrusion (in partnership) and window fabrication. The scope of a G.James plant typically covers everything from float-glass cutting and IGU assembly through to finished window and curtain wall delivery. Multiple sites in Queensland, New South Wales and Victoria. HVAC design for a G.James-scale plant must integrate all six emission profiles in a single facility.
Capral Aluminium — the dominant Australian extruder, supplying mill-finish and finished extrusion to fabricators across the country. Capral's anodising and powder-coating lines are among the largest in the country. Bradnam's Aluminium — the extrusion arm of Bradnam's Windows & Doors, supplying both internally and to other fabricators in Queensland. AluK Australia — the Australian arm of a global aluminium-systems group, supplying premium-tier commercial systems.
Stegbar — a long-running residential fabricator inside the Jeld-Wen Australia group. Broad residential range from entry-level domestic windows through to premium architectural residential. Wideline Windows — residential focus, primarily eastern states. Trend Windows & Doors — long-running residential fabricator with national distribution. Bradnam's Windows & Doors — Queensland-based residential and light commercial. Crystal Windows Australia — residential mid-tier with broad geographic coverage. Lidco — Western Australia residential and light commercial. Lifestyle Windows — Tasmania residential, including bespoke heritage-style work.
Hume Doors & Timber and Corinthian Doors — the two dominant timber and engineered-door manufacturers, with some aluminium and glazed-door scope. Door manufacturing has a different emission profile from window manufacturing — timber dust capture replaces glass-cut silica, but the powder-coat and finishing exhaust requirements are similar to window plants.
Allkind Joinery — bespoke architectural joinery serving commercial fit-out and high-end residential.
AluK Australia and Reynaers Australia — Belgian system houses with Australian operations, supplying high-performance commercial window and façade systems.
YKK AP Australia — commercial systems, primarily curtain wall and shopfront. Permasteelisa Australia — premium façade specialist, delivering bespoke unitised curtain wall for landmark commercial projects. Tilt Industrial — industrial sliding doors and large-format glazing. Apex Architectural — commercial systems. Architectural Glass and Cladding (AGC) — cladded façades.
Viridian Glass (part of CSR) — float-glass processing, IGU assembly, toughened and laminated glass. G.James — integrated glass processing alongside fenestration manufacturing. Pilkington Australia — float-glass processing and IGU supply.
If you are scoping a new fenestration plant or remediating an existing one, the following 28-point checklist captures the engineering decisions that distinguish a long-life ductwork system from a fast-failure one.
When an Australian fenestration manufacturer engages SBKJ for a workshop ventilation duct package, the engagement follows a documented seven-step path.
The standard SBKJ engagement for a mid-scale Australian fenestration plant — 5,000 m² fabrication area, residential and light commercial product mix, integrated anodising, powder-coat, glass processing and IGU assembly — runs three to four months from engagement to commissioning, with the post-commissioning inspection at month 16.
Talk to an SBKJ engineer about your fenestration plant duct package →
The four most important documents are AS 2047 Windows and external glazed doors in buildings, AS 1288 Glass in buildings — selection and installation, AS 4055 Wind loads for housing, and AS 1170.2 Wind actions for commercial structural design. The AWA Australian Window Association certification scheme verifies fabricator compliance with AS 2047 and ties NCC Volume One Section J energy performance values to the supplied window.
Anodising line exhaust is a wet acid mist containing sulfuric acid and chloride ions. Galvanised sheds its zinc coating in months under acid attack, then the exposed mild steel pits and rusts. SBKJ specifies 316L stainless from hood to scrubber because the molybdenum in 316L resists chloride pitting where 304 stainless fails. Above the powder-coat cure oven at 180 to 200 degrees Celsius, the duct must also be stainless — galvanised loses zinc-coating integrity above 200 degrees Celsius.
IGU assembly is functionally a clean room. The unit is sealed with argon or krypton between glass panes with desiccant in the spacer. Dust contaminates the spacer adhesive; humidity saturates the desiccant before sealing. SBKJ specifies HEPA-filtered supply at 12 to 18 air changes per hour, room dew point below 10 degrees Celsius, slight positive pressure, and low-velocity diffusers above sealing tables.
Cure oven exhaust runs 180 to 200 degrees Celsius continuous with VOC and partially cured powder particulates. The correct specification is 316L stainless from oven flange to a downstream cooldown header, with TIG seam-welded flanges and expansion bellows at 10 to 15 metre intervals. SBKJ's SBTF-1602 spiral tubeformer running 1.6 mm stainless coil and a TIG seam welder cover this specification in a single fabrication cell.
AS/NZS 1668.2 sets minimum outside-air rates for office and amenity zones and refers process-air to dilution and capture principles. The practical baseline for an aluminium and glass fabrication floor is six to eight air changes per hour of general dilution supplemented by local-exhaust at every process source — saw cut, CNC, anodising, powder-coat spray booth, cure oven, glass cutting and IGU sealant station. Acoustic budget is typically NC-50 on the open floor.
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