Commercial Printing HVAC Ductwork — Newspaper, Magazine, Book, Packaging & Label Printing Plants

Why a full commercial printing plant is a different HVAC discipline to a newspaper-only plant

We have written elsewhere about the general print sector HVAC discipline and the corrugated and folding carton manufacturing line. Both of those articles approach the print sector from a specific angle. This guide is different. It is written for the duct contractor or mechanical engineer pricing a plant that runs the entire depth of the commercial printing industry under one roof — daily newspaper print on a 50-metre coldset web, magazine work on a 200-metre heatset web with an inline UV coater, sheet-fed B1 offset for trade book covers, sheet-fed B0 for fine-art and folding-carton work, digital toner for personalisation and short-run book runs, digital inkjet for variable-data direct mail, narrow-web flexographic for self-adhesive label, mid-web flexographic for shrink sleeve, rotogravure for flexible packaging and decor laminate, and the full bindery converting finishing and despatch chain that turns all of it into a saleable finished product. Plants of this depth exist in Australia. IVE Group at Silverwater and Mount Waverley runs most of it. The News Corp plant at Chullora runs most of it on the news side. McPhersons Printing Group at Maryborough runs most of it for book. Several of the Visy and Orora packaging sites run most of it for carton and label. The HVAC duct work that ties any one of these plants together is more complex than the duct in a comparable-size pharmaceutical site, a comparable-size food-and-beverage site, or a comparable-size data centre. It is, in our experience, the most demanding generic industrial duct discipline in the country.

The reason is contamination chemistry diversity. A pharmaceutical plant deals with one or two characteristic contaminants that the duct has to manage well. A data centre deals essentially with heat. A meat plant deals with refrigeration and washdown moisture. A full commercial printing plant deals with all of the following simultaneously, in different zones connected by a single building envelope: ink solvent vapour from offset rotogravure and flexographic, infrared and hot-air drying heat from the dryer tunnels, UV light and ozone from the UV cure tunnels, isocyanate crosslinker at 0.005 ppm STEL from the polyurethane UV ink chemistry, ozone and inhalable carbon-black plus rare-earth filler from the toner-based digital sheet-fed lines, fine paper dust and respirable crystalline silica from the kaolin-filled coated paper, toner powder fines from the laser printer banks, IPA fountain solution vapour from the offset wet stock, alkaline mist from the water-based ink, hot melt adhesive vapour from the perfect binding line, lamination heat and adhesive vapour from the sheet lamination line, foil and hot stamp heat from the foiling room, plate developer chemistry from the CTP plate processor, web break paper fluff from any web break in the press hall, dust-explosion risk from any combustible dust accumulation in the bindery trunk, and corona discharge ozone from the printer engines that use corona-based imaging. Every one of those contaminants has a WES — a Workplace Exposure Standard set by Safe Work Australia — that the building HVAC has to hold the operator well below. Several of them have NFPA standards adopted as Australian insurer best practice. All of them have implications for the duct material, the seam construction, the bonding and earthing, the fan selection and the discharge stack height.

The job of this guide is to walk through every one of those zones, name the design assumptions, name the standards that apply, and tell the duct contractor what fabrication shop is needed to hit the specification. We assume the reader is already a competent mechanical engineer or a competent duct contractor; we are not introducing HVAC fundamentals. We are introducing the print-sector overlays that make a full commercial printing plant different from a generic industrial site.

The full code stack — what the duct has to satisfy

Before we get into the zones, we need to lay out the code stack that the duct work has to satisfy. The Australian standards are the binding compliance reference. The NFPA and ASHRAE references are the design references the consulting engineer reaches for when an Australian standard goes silent on a specific question.

AS 1668.2 — Mechanical ventilation in buildings

AS 1668.2 is the spine of the Australian mechanical ventilation framework. It sets minimum outside air rates per occupant for office and customer-facing zones under the National Construction Code Class 5 office classification, and minimum exhaust rates for any space generating contaminants. Every production zone in a commercial printing plant generates contaminants in the sense the standard recognises — solvent vapour, dust, heat, humidity, ozone. AS 1668.2 sets the supply-versus-exhaust relationship that manages pressure differentials between zones and ties to AS 1668.1 on the fire and smoke control role of the air handling system. The practical implications for duct fabrication are leakage performance — duct seam construction must hold to Class C or Class D leakage under DW/144, which the Australian industry adopts by reference — and the registered ventilation rate at every supply and exhaust point, which has to be balanced and witness-tested at commissioning.

AS 4254 — Ductwork construction

AS 4254 Parts 1 and 2 set the construction standard for flexible and rigid HVAC duct in Australia. Part 1 covers flexible duct, which is excluded from any classified hazardous zone and from any contaminated extract trunk in a print plant. Part 2 covers rigid duct in galvanised and stainless steel — gauge selection by static pressure class, seam construction (Pittsburgh, snap-lock, button-punch, TDF, longitudinal weld), reinforcement at large duct sizes, hanger spacing and access door construction. Every duct line in a commercial printing plant has to be fabricated to AS 4254 Part 2. The SBAL-V auto duct line produces TDF rectangular duct to Class C and Class D leakage standards out of the box on galvanised and 304 stainless coil up to 1.5 millimetres thickness. The SBSF-1525 spiral tubeformer produces round spiral duct to the same standard from 100 to 1,500 millimetres diameter.

AS 1530.4 — Fire-resistance of building elements

AS 1530.4 sets the test method for fire-resistance of building elements including duct penetrations through fire-rated walls and floors. Every commercial printing plant has multiple fire-load zones — the paper warehouse, the ink mix room, the bulk solvent store, the dryer and oven area, the pressroom proper, the bindery and the finished goods warehouse. Duct passing through a fire-rated wall between two zones has a fire damper installed at the wall line, certified to AS 1682 and held open by a fusible link or smoke detector. The dampers fail closed on fire and isolate the duct system, preventing fire propagation between zones. The duct fabrication shop has to deliver wall sleeves and matched fire dampers at every penetration on the project drawings.

AS 1851 — Routine servicing of fire protection systems

AS 1851 sets the routine servicing regime for fire dampers smoke dampers fire-rated dampers and the associated control systems. The implication for the duct designer is access — every fire damper needs an access door immediately on the non-classified side of the penetration sized for a person to reach in and reset the damper. The SBPC1500 plasma cutter cuts the access door openings clean and the access door frames are fabricated from the same coil as the surrounding duct.

AS 1657 — Fixed platforms walkways stairways and ladders

AS 1657 sets the construction standard for fixed access infrastructure including the platforms walkways and ladders associated with roof-mounted duct serving the heatset dryer trunk and the RTO. The duct contractor delivers integrated access platforms at every fan service point and every damper.

AS/NZS 60079 — Explosive atmospheres

AS/NZS 60079.10.1 sets the hazardous area classification framework — Zone 0, Zone 1 and Zone 2 for gas and vapour atmospheres. AS/NZS 60079.14 sets the electrical installation rules in those classified zones, driving the choice of Ex-rated motors fans dampers and instrumentation. AS/NZS 60079.17 sets the inspection and maintenance regime. In a commercial printing plant the classified zones are typically the ink mix room (Zone 2 across the room with a Zone 1 envelope around the decanting station), the bulk solvent store (Zone 2 across the store with Zone 1 around any open container), the rotogravure deck (Zone 1 close to the cylinders Zone 2 across the rest), the solvent flexographic deck (Zone 1 close to the cylinders Zone 2 across the rest) and the immediate vicinity of any UV ink decanting where the chemistry is solvent-based. The duct in every classified zone is bonded earthed metal — galvanised lower-risk Zone 2 or stainless higher-risk Zone 1 — with conductive gaskets at flanges no internal acoustic liners and continuous earth bonding to a single ground point per zone. The exhaust fan is Ex-d (flameproof enclosure) ATEX-rated with a spark-resistant impeller.

AS 1940 — Storage and handling of flammable and combustible liquids

AS 1940 covers the storage and handling of the bulk ink and solvent inventory. A commercial printing plant typically holds several thousand litres of ink and solvent across multiple SKUs at any time — offset web ink, offset sheet-fed ink, UV ink (acrylate or PU crosslinker), water-based ink for inkjet, solvent ink for rotogravure, alcohol-based fountain solution, plate developer, blanket wash, roller wash, IPA and a long tail of speciality coatings and lacquers. The bulk store has bunded floor, secondary containment around every drum, spill kits, fire suppression, spark detection, separation distance from ignition sources and ventilation to keep the vapour concentration well below the lower explosive limit. The HVAC duct serving the bulk store is bonded earthed stainless or galvanised on continuous extract from low level.

AS 3957 — Dust ventilation

AS 3957 covers dust extraction system design including capture velocity transport velocity duct sizing collector sizing and discharge requirements. The standard applies to the paper dust trunk in the bindery the toner dust trunk in the digital sheet-fed hall and any other particulate-generating zone. Transport velocity in a paper dust trunk is 18 to 22 metres per second. Capture velocity at the cutter folder gatherer trimmer is 0.5 to 1.0 metres per second across the capture face. Collector type is baghouse or cartridge with explosion venting under NFPA 660.

NFPA 660 — Combustible dust

NFPA 660 (the consolidated combustible dust standard replacing the legacy NFPA 654 654 484 61 91 and 664 family) covers the combustible dust hazard analysis the explosion venting the isolation devices the housekeeping regime and the electrical classification. Paper dust at low humidity is a recognised combustible dust under NFPA 660, classified historically as Class II Group G. Toner powder is also a combustible dust. The implication for the duct design is explosion venting on the collector body isolation devices on the inlet duct to prevent flame propagation back into the building and bonded earthed metal duct throughout.

NFPA 33 — Spray application

NFPA 33 is the US standard for spray application of flammable and combustible materials. It is referenced by Australian insurers as best practice for the UV cure spray coater the water-based inline coater the lacquer spray booth on any inline finishing line and any cold seal or hot melt adhesive spray station. The standard sets booth ventilation rates duct construction clean-out requirements and the interlock between the coater and the exhaust system. For fabrication: smooth-bore stainless duct from booth to discharge no horizontal collection runs frequent clean-out doors no flexible duct on the contaminated side.

NFPA 86 — Industrial ovens and furnaces

The heatset web offset dryer is, in NFPA 86 terms, an oven. The IR ink drying tunnel is an oven. The hot-air drying tunnel on a coldset newspaper press is a milder oven. All three drive off solvent or water hold the substrate at temperature long enough for the ink to set and exhaust to an oxidiser or atmosphere. NFPA 86 sets the minimum exhaust rate (typically four air changes per minute of heated volume) the minimum dilution to keep the inlet below 25 percent of LEL the burner shutdown interlock chain and the duct construction between dryer hood and oxidiser inlet. The duct is 304 stainless minimum 316L preferred TIG full-penetration longitudinal seams expansion joints on any run over 10 metres insulation rated for operating temperature plus margin and trace heating on roof runs.

AS 1318 — Industrial chimneys

AS 1318 covers the construction of industrial chimneys including the discharge stack from any heatset web offset dryer the rotogravure RTO outlet and the UV cure tunnel discharge. Stack height is set by AS 3580 dispersion modelling and local EPA conditions. The stack is fabricated from 304 or 316L stainless on the contaminated side galvanised on the cool downstream side after any heat recovery exchanger.

AS 4036 and AS 4037 — Boilers and pressure vessels

AS 4036 and AS 4037 cover the boilers and pressure vessels associated with the IR ink drying tunnels the hot-air drying tunnels and the steam supply for the humidification of the pressroom. The duct contractor coordinates with the boiler vendor on flue routing and combustion air supply.

NCC Class 8 Class 5 and Class 7b

The National Construction Code classifies a commercial printing building as Class 8 industrial (the press hall, the dryer area, the bindery, the ink mix room, the solvent store) with Class 5 office (the administration sales and production planning areas) and Class 7b warehouse (the paper store and the finished goods warehouse). Each classification carries different fire-resistance ratings exit width requirements and ventilation requirements. The duct routing has to respect the classification boundary lines and provide fire-rated penetrations at every wall and floor crossing.

ASHRAE Applications Chapter 33 and Chapter 38

The ASHRAE Applications Handbook Chapter 33 industrial ventilation and Chapter 38 industrial drying are the design references the consulting engineer reaches for when an Australian standard is silent on a specific question — capture velocities for a specific source the design of a paint or coating spray booth the heat balance on a dryer hood. ASHRAE is referenced as best practice not as a binding code in the Australian compliance framework.

ISO 12647 — Process control for the production of half-tone colour separations

ISO 12647 is the colour management standard the commercial printing industry works to. It sets the target conditions for the substrate the ink the press and the operating environment. The operating environment includes the pressroom temperature and humidity. ISO 12647 sets the pressroom at 22 to 24 degrees Celsius dry bulb and 50 percent relative humidity within a tight tolerance band. The HVAC duct work has to hold the room at that band year-round in the Australian climate. ISO 14064 carbon accounting is the related standard the publisher and the brand owner are increasingly imposing on the printer.

AS 4801 — OHS management system

AS 4801 sets the framework for the workplace health and safety management system. It is the integrating document under which all the contaminant exposure standards, the hazardous area classifications, the fire and dust hazard analyses, and the routine inspection regimes get tied together at site level. The duct contractor produces a safe-work method statement and a hazardous-area drawing pack that fold into the operator's AS 4801 system.

Industry bodies that set the operator expectations

The Australian Graphic Communications Council (AGCC) is the peak industry body. The Printing Industries Association of Australia (PIAA) is the trade association covering the commercial print sector at large. The Australian Book Publishers Association (IBPA) Magazine Publishers Australia (MPA) and the Newspaper Marketing and Sales Association (NMSA) cover the publisher side. The Visual Magazine and Newspaper Industries Association covers the production side of magazines and newspapers. The Royal Australian Book Industry Awards (RBA) is the recognition framework. None of these bodies are regulators — they do not set duct specifications — but they do set the published expectations on quality safety and environmental performance that the operator carries into the duct procurement.

The eight HVAC zones of a full commercial printing plant

A full commercial printing plant is, functionally, eight to twelve distinct HVAC zones connected by a single building envelope. Each zone has its own temperature humidity pressure relationship and contamination profile. The duct system has to deliver supply return and exhaust to each zone independently while maintaining the pressure differentials between zones and the fire-rated boundaries between fire-load areas. Ranked from most demanding on the mechanical services to least demanding:

Zone 1 — Heatset web offset dryer trunk and rotogravure RTO inlet

The hottest dirtiest and most consequential duct in the building. Heatset web offset dryers run at 200 to 280 degrees Celsius on the exhaust stream. Rotogravure dryers run cooler — typically 100 to 150 degrees Celsius — but with much higher solvent loading. Solvent flexographic dryers fall between the two. The duct from the dryer hood to the RTO inlet plenum is fabricated from 304 stainless minimum 316L preferred. The longitudinal seam is TIG-welded full-penetration produced on the SB-ZF1500 stitchwelder with root protection and post-weld passivation. Wall thickness is 1.5 to 2.0 millimetres depending on diameter and span. Expansion joints on any run over 10 metres because the duct sees a 250 degree Celsius swing every shift start. Insulation is calcium silicate or ceramic-fibre blanket 75 to 100 millimetres thick clad in galvanised or stainless sheet metal. Trace heating is mandatory on any external roof run.

Zone 2 — UV cure tunnel ozone extract and IR drying tunnel exhaust

The UV cure tunnel is a smaller-volume but more chemistry-diverse duct than the heatset dryer trunk. UV lamps at 365 nanometre UV-A — mercury vapour or LED — cure acrylate or PU-crosslinker ink in a tunnel between 1 and 5 metres long. The tunnel exhausts photoinitiator vapour ozone from the lamp interaction with air and on PU chemistry isocyanate crosslinker at 0.005 ppm STEL. The duct is 304 stainless from the tunnel to the discharge stack with stitchwelded seams. The face velocity at the tunnel inlet is set at 0.5 metres per second minimum and the air change rate inside the tunnel enclosure is 30 air changes per hour minimum. An ozone destructor — a heated catalytic converter — sits on the discharge if the stack is close to occupied buildings. The IR ink drying tunnel runs at 800 to 1,200 nanometres infrared gas-fired or electric. The exhaust is hot air at 100 to 200 degrees Celsius with minor solvent or water vapour. The duct is 304 stainless from tunnel to discharge.

Zone 3 — Ink mix room (ink kitchen) and bulk solvent store

The ink mix room is small (20 to 60 square metres) classified Zone 2 under AS/NZS 60079.10.1 with a Zone 1 envelope around the decanting station. The bulk solvent store is larger (often 100 to 300 square metres) classified Zone 2 across the floor with Zone 1 around any open container. Both zones have AS 1940 secondary containment bunded floor spill kits spark detection and fire suppression. The HVAC duct is 304 stainless bonded earthed continuously. Extract is from low level because solvent vapour is denser than air. Make-up is from high level through a passive louvre. The fan is Ex-d ATEX-rated centrifugal with spark-resistant impeller in 304 stainless. Ventilation rate is 6 to 10 air changes per hour minimum on continuous operation. The duct in this zone is fabricated on the SBAL-V in stainless coil with the SB-ZF1500 stitchwelder finishing the seam on the contaminated extract side.

Zone 4 — Pressroom proper (offset sheet-fed web and digital)

The pressroom holds 22 to 24 degrees Celsius dry bulb at 50 percent relative humidity year-round for ISO 12647 colour management. Tolerance is plus or minus 2 degrees and plus or minus 5 percent on standard work tighter on fine-art reproduction security printing and high-end packaging. The duct is galvanised G90 spiral on the supply (lower leakage and better acoustic performance than seamed rectangular at the same area) and galvanised G90 rectangular TDF on the returns and the lower-velocity transfers. F7 filtration minimum F9 on colour-critical lines and a carbon stage if the plant is downwind of a recycling depot or other odour source. The AHU is chilled-water packaged or central chiller AHU with dehumidify-and-reheat capability for the Australian summer and steam or evaporative humidification for the winter. Slight positive pressure relative to dryer area warehouse and bindery.

Zone 5 — Pre-press CTP plate room and proofing

A smaller volume than the pressroom (typically 100 to 500 square metres) but holding the tightest tolerance band in the plant. CTP plates are aluminium sheet with a photopolymer or thermal emulsion. The plate processor is a wet bath of developer gum and rinse. The proofing area is essentially a clean office. The room is held at 22 to 24 degrees Celsius and 50 percent relative humidity within plus or minus 1 degree and plus or minus 5 percent positively pressured relative to the pressroom and the warehouse to keep paper dust and solvent vapour out. Duct is galvanised G90 throughout. The AHU is a dedicated packaged unit.

Zone 6 — Bindery finishing converting foiling lamination and coating

The bindery is where the printed substrate becomes the finished product — folded sections gathered books perfect-bound or saddle-stitched magazines case-bound books die-cut cartons trimmed labels embossed and foiled covers laminated sheet and inline coating finishes. Every process generates paper dust. A high-speed perfect binder running at 12,000 books per hour generates a continuous stream of fine paper dust from the spine grinder the trim knives and the gathering chain. The HVAC duct is two parallel systems: a comfort HVAC providing tempered air for the operators and a dedicated low-pressure dust extraction trunk taking paper dust from every cutter folder gatherer and trimmer back to a baghouse or cartridge collector. The dust trunk is galvanised G90 fabricated on the SBSF-1525 spiral tubeformer with clean-out doors at every elbow transport velocity 18 to 22 metres per second bonded and earthed continuously. The hot-melt adhesive perfect binding line adds minor heat and adhesive vapour managed by local exhaust ventilation. The lamination line adds heat and adhesive vapour also managed by local exhaust. The foiling and hot-stamp room runs at 80 to 120 degrees Celsius with minor adhesive vapour. The coating line — UV varnish water-based gloss dispersion coating or aqueous — adds solvent VOC UV cure and IR cure depending on the configuration.

Zone 7 — Mailroom inserting despatch and finished goods warehouse

The mailroom is essentially a logistics environment with light machinery — single-shot mass-mailing flatbed inserters address printers folding machines. The HVAC is comfort-grade ambient at AS 1668.2 minimum outside air rates for the occupancy F5 or F7 filtration no special humidity control. Galvanised G90 duct throughout. The finished goods warehouse is climate-controlled at 18 to 22 degrees Celsius and 40 to 60 percent relative humidity to keep the paper-based finished goods stable. Refer the Australia Post parcel and ecommerce fulfilment HVAC duct guide for the despatch and truck loading detail because the design pattern is the same.

Zone 8 — Office administration sales production planning press control and quality control

Standard commercial HVAC under AS 1668.2 separate packaged unit not on the process loop. The press control room — where the G7 CIP4 and RTO control electronics live — has redundant cooling and additional filtration because automated colour management electronics are heat-sensitive. The quality control room — densitometer spectrophotometer colourimeter — is held at the same 22 to 24 degree Celsius and 50 percent relative humidity band as the pressroom because the colour measurement instruments calibrate against the press condition.

Newspaper web offset — the long-form spine

The newspaper web press is the longest single piece of machinery in any commercial printing plant — typical lengths run 50 to 200 metres from reel-stand to folder for a modern Heidelberg Goss or manroland install. Australian newspaper print is dominated by News Corp Australia (Murdoch) Nine Publishing (formerly Fairfax) and Australian Community Media (Antony Catalano). News Corp prints the Sydney Daily Telegraph the Herald Sun Melbourne the Courier Mail Brisbane the Adelaide Advertiser the NT News and The Australian on a small number of large regional plants — Chullora Sydney Westgate Melbourne and the regional sites. Nine Publishing prints the Sydney Morning Herald The Age and the Australian Financial Review through its Sydney and Melbourne plants. ACM runs more than 140 regional mastheads including the Newcastle Herald the Canberra Times the Illawarra Mercury the Western Advocate Bathurst the Western Magazine the Daily Liberal Dubbo and a long tail of community titles on smaller regional print plants. The West Australian (Seven West Media ASX:SWM) prints from Perth. The Townsville Bulletin the Cairns Post and the Daily Mercury Mackay run on News Regional plants.

The HVAC duct on a newspaper web press hall is dominated by paper-dust extraction at every web break fluff capture at the folder pressroom comfort with humidity above 40 percent for static control and IR or hot-air drying tunnel exhaust on any heatset combination press. A coldset-only newspaper press has no oven exhaust requirement — ink dries by absorption into the porous newsprint — so the duct is essentially galvanised G90 throughout fabricated on the SBAL-V auto duct line. A heatset combination press for magazine work on coated newsprint or LWC paper has the full heatset dryer trunk discussed in Zone 1 — 304 stainless from dryer hood to RTO inlet on the SB-ZF1500 stitchwelder. The press hall pressroom comfort is held at 22 to 24 degrees Celsius with humidity above 40 percent rather than the tight ISO 12647 band because newsprint is more forgiving than coated paper. The folder dust extraction trunk is the most demanding non-thermal duct in the building — high transport velocity galvanised G90 spiral on the SBSF-1525 with clean-out doors at every elbow bonded and earthed under NFPA 660 with explosion venting on the collector body.

The corona discharge ozone at the printing nip on any electrostatic-assist or static-elimination system adds a minor ozone load to the pressroom return. Ozone at 0.1 ppm WES is the design driver — the air change rate in the press hall has to be sufficient to hold the operator below the WES on a moving 8-hour TWA basis.

Commercial offset sheet-fed press — B0 B1 and B2 size

The sheet-fed offset press is the workhorse for the full commercial printing industry — magazines books book covers folding cartons labels brochures direct mail and a long tail of trade and speciality work. Australian sheet-fed offset is dominated by Heidelberg Speedmaster Komori Lithrone manroland Roland 700 and KBA Rapida. Sheet sizes are B2 (50 by 70 centimetres) B1 (70 by 100 centimetres) and B0 (100 by 140 centimetres). B1 is the workhorse for trade work; B0 is reserved for folding-carton and fine-art reproduction; B2 covers labels and smaller commercial work. Major sheet-fed operators in Australia include IVE Group (ASX:IGL — formerly Blue Star — the largest commercial printer multi-state Sydney Melbourne Brisbane Perth Adelaide) the Argyle Group (which acquired several Ovato segments after Ovato went into administration in 2024) Lane Print Group Printcraft Brisbane McPhersons Printing Group (Maryborough VIC — the largest book printer with an Ingram Spark partnership for print-on-demand) Ligare Book Printers (Sydney and Melbourne) Bolton Imaging (Melbourne POD) Doran Printing Melbourne Heatset Printing Sydney Pinnacle Print Group multi-state Carbon Group Communications Sydney Webcity and Web Star Group.

The HVAC duct on a sheet-fed offset hall is dominated by pressroom comfort IPA fountain vapour management and minor solvent extract. Ink dries by oxidation over hours so there is no heatset-scale oven. Some lines run inline UV curing for spot varnish (adds UV exhaust and ozone removal — Zone 2 above) or an IR drying tower for inline coating (small-scale dryer exhaust — Zone 1 territory if above 200 degrees Celsius surface temperature). Some lines run a water-based alkaline dispersion coating for gloss or matt — adds aqueous mist and minor alkaline aerosol managed by local exhaust. The pressroom holds 22 to 24 degrees Celsius and 50 percent relative humidity to ISO 12647 within plus or minus 2 degrees and plus or minus 5 percent. F7 minimum supply filtration; F9 on colour-critical work. Duct is galvanised G90 spiral on supply rectangular on return.

IPA in fountain solution is the underappreciated chemistry on a sheet-fed press. Even alcohol-reduced fountains running at 1 to 3 percent IPA produce significant cumulative evaporation across a pressroom of running presses — the WES of IPA is 400 ppm and the building has to hold the operator well below that. Duct is galvanised throughout except the IPA extract directly at the press fountain which is bonded earthed metal in line with AS/NZS 60079.

Digital web press — inkjet variable-data

The digital web press is the newest format in the commercial printing plant — HP PageWide Canon ProStream Kodak NexPress and the related water-based inkjet systems. Digital web is used for variable-data direct mail short-run book printing transactional documents (statements bills invoices) and personalised catalogue. Major Australian operators of digital web include IVE Group at Silverwater Bolton Imaging in Melbourne (specialising in print-on-demand book) and several of the News Corp Nine and ACM plants for variable-data inserts. The chemistry is water-based ink — very low VOC very low odour minor IR drying. The HVAC duct is essentially pressroom comfort HVAC galvanised G90 throughout with a small IR exhaust at the dryer. F7 minimum filtration ISO 12647 colour-managed at 22 to 24 degrees Celsius and 50 percent relative humidity. Positively pressured relative to the offset hall to keep paper dust and solvent vapour out of the digital line.

Digital sheet-fed press — toner and inkjet

The digital sheet-fed press covers HP Indigo Xerox Konica Minolta Canon imagePRESS and the Ricoh Pro family. Indigo is liquid-electrophotographic (a niche toner technology) the others are dry toner. Some Indigo and Canon variants run UV cure (Indigo with a UV curable substrate film Canon with a UV inkjet ink set). The chemistry is toner — fine particulate carbon black and iron oxide on monochrome with rare-earth fillers on colour (cerium praseodymium neodymium lanthanum samarium europium dependent on the printer model). Toner WES is 5 milligrams per cubic metre inhalable and 1 milligram per cubic metre respirable. The print engine generates ozone from corona discharge — 0.1 ppm WES. The fuser bakes the toner onto the substrate at 150 to 200 degrees Celsius generating minor heat and a small VOC plume from the toner resin binder.

The HVAC duct on a digital sheet-fed hall is galvanised G90 throughout. Pressroom comfort at 22 to 24 degrees Celsius and 50 percent relative humidity. The toner dust extract is a small dedicated trunk at each printer or at the bank — typically 200 to 500 cubic metres per hour per printer — to capture the corona ozone and any escaping toner fines. The trunk is galvanised G90 with a HEPA filter on the discharge before recirculation back to the hall or discharge to atmosphere. NFPA 660 applies to the toner dust collector because toner is a combustible dust. The hall is positively pressured relative to the offset hall to keep paper dust and solvent vapour out of the digital line.

Flexographic and rotogravure — solvent capture and RTO

Flexographic and rotogravure printing dominate the label and packaging segment of the Australian commercial printing industry. Flexographic runs on a rubber or photopolymer plate water-based ink (corrugated brown box) solvent-based ink (non-absorbent film) or UV-cured ink (labels and high-end packaging). Rotogravure runs on an engraved chrome-plated copper cylinder solvent-based ink at high volume for flexible packaging shrink sleeve and decor laminate. The major flexographic and gravure equipment vendors are Bobst Switzerland W&H Germany Comexi Spain Cerutti Italy and Uteco Italy. Major Australian operators of flexographic and rotogravure include Pact Group (ASX:PGH — rigid plastic packaging with overlap to the plastic polymer manufacturing HVAC guide) Visy Industries (Pratt Family — carton corrugated plastic and glass — multi-site) Amcor (ASX:AMC — flexible packaging multi-site) Orora (ASX:ORA — paper carton glass can plastic — Box Hill VIC HQ down the road from the SBKJ engineering office) Multi-Color Corporation Australia (US-acquired — label printing) ePac Flexible Packaging (US-listed multiple Australian plants) Detmold Group (Adelaide — coffee cup and plate) and at the integrated end the Australian Paper Manufacturers paper mill at Maryvale VIC.

The HVAC duct on a solvent-based flexographic or rotogravure deck is the most chemistry-intensive duct in the commercial printing sector. The press hall is a classified hazardous area under AS/NZS 60079.10.1 — Zone 1 close to the cylinders Zone 2 across the rest of the press hall. Every deck has an enclosed solvent dryer feeding a regenerative thermal oxidiser (RTO) for VOC abatement. Solvent loadings are 1,500 to 3,000 ppm at the dryer inlet at full press speed; the RTO destroys 98 to 99 percent of that on the way to atmosphere. The duct from the dryer hood to the RTO inlet is fully welded 304 stainless minimum 316L preferred. The inlet plenum on the RTO is fabricated as a custom item from 304 stainless on the SB-ZF1500 stitchwelder with bonded earthed flanges and conductive gaskets at every joint. The press hall return air is taken at low level because solvent vapour is denser than air. Ex-d ATEX-rated centrifugal fans with spark-resistant impellers throughout the contaminated side.

Water-based flexographic — the corrugated post-print case — is the simplest end of the spectrum. No classified zone no RTO required minimal ventilation beyond comfort HVAC and a local extract at any inline coating. Galvanised G90 duct throughout. UV flexographic — labels and high-end packaging — has the UV cure tunnel ozone extract discussed in Zone 2 plus a local extract at the UV ink decanting station which is a small Zone 2 envelope.

Ink mix room (ink kitchen) — the room that decides insurability

The ink mix room is the room where solvent ink water-based ink and UV ink is weighed blended and tinted to match the Pantone or brand colour book for the job in hand. Volume is small typically 20 to 60 square metres but it contains open ink drums solvent drums and dispensing equipment that release vapour at concentrations approaching the lower explosive limit under inadequate ventilation. The ink mix room is, in our experience, the room that decides whether the plant is insurable. Every solvent ink fire we know of in the Australian commercial print sector has started in the ink mix room.

The ventilation specification is non-negotiable. Classified Zone 2 across the room with a Zone 1 envelope around the decanting station under AS/NZS 60079.10.1. AS 1940 secondary containment around every drum bunded floor spill kits spark detection and fire suppression. Ventilation rate 6 to 10 air changes per hour minimum continuous extract from low level (solvent vapour is denser than air) make-up from high level through a passive louvre. The fan is an Ex-d ATEX-rated centrifugal in 304 stainless with spark-resistant impeller. The duct is bonded earthed 304 stainless from the room to the discharge stack with no internal acoustic liner and TIG-welded longitudinal seam produced on the SB-ZF1500 stitchwelder. Discharge stack height set by AS 1318 and AS 3580 dispersion modelling. Spark detection in the duct at the discharge to the fan. Fire suppression coverage of the room including the ductwork access doors.

The ink mix room duct work is small — typically 20 to 40 metres of stainless duct and one Ex-d fan — but it is engineering-led work that consumes more design and fabrication attention per metre than any other duct in the plant. The duct contractor that gets this room right earns the next ten projects from the operator. The contractor that gets it wrong typically loses access to the operator entirely after the first fire incident.

Bulk solvent store and ink store

The bulk solvent store sits adjacent to the ink mix room and holds the working inventory of ink solvent fountain solution blanket wash roller wash plate developer and the long tail of speciality coatings and lacquers. A typical commercial printing plant holds several thousand litres across these SKUs at any time. AS 1940 sets the storage segregation bunded floor secondary containment ventilation and the separation distance from ignition sources. The HVAC duct is similar in specification to the ink mix room — Zone 2 across the floor Zone 1 around any open container 304 stainless bonded earthed extract on continuous operation Ex-d ATEX-rated centrifugal fan with spark-resistant impeller. Ventilation rate is 4 to 6 air changes per hour (lower than the ink mix room because the chemistry is in sealed containers most of the time). Sprinkler coverage to AS 2118. Foam suppression on solvent above the threshold flash point.

The bindery — paper dust and the NFPA 660 implications

The bindery and finishing end of a commercial printing plant is where the printed substrate becomes the finished product. Folded sections gathered books perfect-bound or saddle-stitched magazines case-bound books die-cut cartons trimmed labels embossed and foiled covers laminated sheet hot-melt adhesive perfect binding and inline coating finishes. Every one of these processes generates paper dust. A high-speed perfect binder running at 12,000 books per hour generates a continuous stream of fine paper dust from the spine grinder the trim knives and the gathering chain. A high-speed saddle stitcher generates trim waste at the cutting station. A high-speed die-cutter generates carton waste at the chopper. The dust load is significant — a mid-sized commercial bindery generates 20 to 50 kilograms of paper dust per shift across all the lines.

The HVAC duct specification for the bindery is two parallel systems: a comfort HVAC providing tempered air for the operators (galvanised G90 spiral fabricated on the SBSF-1525 supply F5 to F7 filtration ambient temperature) and a dedicated low-pressure dust extraction trunk taking paper dust from every cutter folder gatherer trimmer die-cutter and laminator back to a baghouse or cartridge collector. The dust trunk is galvanised G90 with smooth interior seams to prevent fibre accumulation transport velocity 18 to 22 metres per second clean-out doors at every elbow bonded and earthed continuously under NFPA 660.

The NFPA 660 implications are non-negotiable. Paper dust at low humidity is a recognised combustible dust historically classified as Class II Group G in US practice and treated equivalently under Australian dust-explosion guidance under AS 3957 and NFPA 660. The dust trunk has explosion venting on the collector body isolation devices on the inlet duct to prevent flame propagation back into the building bonded earthed metal duct throughout no flexible duct and a housekeeping regime that holds the dust accumulation in the building below the threshold dust layer thickness. Static charge management is mandatory because dry paper dust at low humidity holds a static charge that can ignite the dust cloud. The fabrication shop produces the dust trunk on the SBSF-1525 spiral tubeformer at the size range (typically 250 to 600 millimetres diameter on branches up to 1,200 millimetres on the main) with clean-out doors fabricated on the SBPC1500 plasma cutter from the same galvanised coil.

The baghouse or cartridge collector is sized for the cumulative dust load with a safety margin of 30 to 50 percent on the design flow. Discharge is either back into the plant after filtration (cleaner air recirculation reducing make-up air heating load in winter) or to atmosphere depending on local odour and dust rules. The recovered paper dust is bagged and sold to recycling or to firestarter manufacturers — it is a small revenue stream rather than a waste cost.

Lamination foiling and coating — minor heat and adhesive vapour

The lamination department sheet lamination gloss film matt film cold seal pressure-sensitive lamination — adds heat and adhesive vapour to the bindery extract trunk. The duct is galvanised G90 with a local extract at the laminator nip at 0.5 to 1.0 metres per second capture velocity transport velocity 12 to 15 metres per second (slower than paper dust because the load is mostly vapour not particulate) back to a carbon adsorber if the adhesive is solvent-based or directly to atmosphere if the adhesive is water-based or hot-melt.

The foiling and hot stamp room runs at 80 to 120 degrees Celsius with metallic foil or pearlescent film transferred to the substrate by a heated die. Minor heat and adhesive vapour. The HVAC is comfort HVAC with a local extract at each foiling station. Duct is galvanised G90.

The coating line — UV varnish water-based gloss dispersion coating aqueous spot UV — adds VOC UV cure and IR cure depending on the configuration. UV coating runs through a UV cure tunnel (Zone 2 in the framework above) — 304 stainless extract on the SB-ZF1500 stitchwelder. Water-based coating runs through an IR or hot-air drying tunnel — Zone 1 territory if above 200 degrees Celsius surface temperature 304 stainless on the SB-ZF1500. Aqueous coating is the simplest — minor water vapour and a small local extract. Cold foil and holographic foil are minimal — comfort HVAC.

Book printing — book block casebound paperback children's

Book printing is a specialised segment of the commercial printing industry. Australian book print is concentrated at McPhersons Printing Group (Maryborough VIC — the biggest book printer historic — with an Ingram Spark partnership for print-on-demand) Ligare (book printing — Sydney and Melbourne) and Bolton Imaging (Melbourne POD). The publishers — Penguin Random House Australia (Bertelsmann) HarperCollins Australia (Murdoch — News Corp) Hachette Australia (Lagardere French) Macmillan Australia Allen & Unwin (the largest independent) Bloomsbury Australia Simon & Schuster Australia Affirm Press (Melbourne fiction) Black Inc Books (Melbourne non-fiction) and Text Publishing (Melbourne) — contract their print to one of those three book printers or to a smaller specialist. The Australian Book Publishers Association (IBPA) and the Royal Australian Book Industry Awards (RBA) are the industry bodies.

The HVAC duct on a book printing plant is essentially the offset sheet-fed plant (book block and book covers) plus the bindery (case binding perfect binding saddle stitching adhesive binding) plus the warehouse (climate-controlled finished goods). McPhersons Maryborough runs a mix of heatset web offset (for high-volume book block) sheet-fed offset (for book covers and short-run titles) digital sheet-fed (for print-on-demand) and a full bindery. The duct mix is roughly 60 percent galvanised G90 (pressroom comfort bindery dust warehouse and office) 30 percent stainless on the dryer trunk and RTO inlet and 10 percent stainless on the UV and IR cure tunnels on the inline coating.

Digital on-demand book printing — Lightning Source Ingram Spark Bolton Imaging — runs on digital sheet-fed printers with inline perfect binding or saddle stitching. The HVAC is the digital sheet-fed hall plus a small bindery extract. Galvanised G90 throughout. F7 filtration. ISO 12647 colour-managed at 22 to 24 degrees Celsius and 50 percent relative humidity.

Magazine production — heatset and saddle stitch

Magazine production is dominated by Are Media (formerly Bauer — the largest magazine publisher in Australia with Cosmopolitan Marie Claire Women's Weekly Better Homes and Gardens and Take 5 in the portfolio) News Magazines (News Corp) Pacific Magazines (Seven West Media) and a long tail of independent titles. Magazine print is contracted to IVE Group the Argyle Group and a few specialist heatset commercial printers. The format is heatset web offset on coated paper — the highest-quality colour reproduction in the commercial printing industry — with inline saddle stitching or perfect binding. Magazine Publishers Australia (MPA) is the industry body.

The HVAC duct on a magazine printing line is the heatset web offset trunk discussed at length above — 304 stainless from dryer hood to RTO inlet on the SB-ZF1500 stitchwelder. The pressroom is held tight at ISO 12647 — 22 to 24 degrees Celsius and 50 percent relative humidity within plus or minus 2 degrees and plus or minus 5 percent. The bindery runs the saddle stitcher or perfect binder with the full paper dust extraction trunk under NFPA 660. The mailroom inserts the printed magazine into the polywrap or paper wrap for despatch. The duct is galvanised G90 except the dryer trunk and the inline coating cure tunnel.

Label printing — narrow-web flexographic and digital

Label printing is a specialised segment dominated by Multi-Color Corporation Schiff Australia Industrial Press and Australian Print Group (label specialist). The format is narrow-web flexographic (typically 250 to 500 millimetre web width) running UV-cured ink water-based ink or solvent ink on self-adhesive face stock with a release liner. Digital label printing is growing — HP Indigo narrow web Mark Andy Digital Series Domino Durst — typically on water-based inkjet or UV inkjet.

The HVAC duct on a label printing line depends on the ink chemistry. UV flexographic — Zone 2 UV cure tunnel ozone extract 304 stainless on the SB-ZF1500 plus local extract at the UV ink decanting station. Solvent flexographic — full Zone 1 / Zone 2 hazardous area treatment under AS/NZS 60079.10.1 with 304 stainless dryer trunk to RTO inlet bonded earthed throughout Ex-d ATEX-rated fans. Water-based flexographic — Zone 0 classified envelope minimal a small local extract at the dryer galvanised G90 elsewhere. Digital UV inkjet — Zone 2 UV cure tunnel extract galvanised G90 elsewhere. Digital water-based inkjet — galvanised G90 throughout with small IR extract.

Packaging printing — folding carton corrugated and flexible

Packaging printing is the largest growth segment of the Australian commercial printing industry by value. Folding carton runs on sheet-fed offset (B0 or B1) with inline coating UV or water-based — galvanised G90 plus a small Zone 1 dryer trunk and Zone 2 UV cure tunnel. Corrugated post-print runs on water-based flexographic — galvanised G90 throughout no classified zone. Flexible packaging runs on solvent rotogravure or solvent flexographic — full Zone 1 / Zone 2 treatment 304 stainless dryer trunk to RTO inlet Ex-d ATEX-rated fans.

Major Australian operators: Pact Group (ASX:PGH — rigid plastic packaging — overlap with the plastic polymer manufacturing HVAC guide) Visy Industries (Pratt Family — carton corrugated plastic and glass — multi-site — refer the container glass packaging HVAC guide for the glass segment) Amcor (ASX:AMC — flexible packaging — multi-site) Orora (ASX:ORA — paper carton glass can plastic — Box Hill VIC HQ down the road from SBKJ engineering) Multi-Color Corporation Australia (label) ePac Flexible Packaging (multiple Australian plants) Detmold Group (Adelaide — coffee cup and plate) and the Australian Paper Manufacturers paper mill at Maryvale VIC (paper supply rather than print).

Pre-press CTP plate making — the cleanest zone

The pre-press computer-to-plate (CTP) plate room is the cleanest zone in the commercial printing plant. CTP plates are aluminium sheet with a photopolymer or thermal emulsion. The CTP imager — Heidelberg Suprasetter Kodak Trendsetter Fujifilm Luxel — burns the digital image onto the plate. The plate processor is a wet bath of developer gum and rinse — water-based mild caustic with the developer chemistry varying by plate type. The proofing area is essentially a clean office with calibrated proofing printers and a viewing booth at D50 lighting.

The HVAC duct is galvanised G90 throughout. The room is held at 22 to 24 degrees Celsius and 50 percent relative humidity within plus or minus 1 degree and plus or minus 5 percent — tighter than the pressroom because the plate dimensions and the emulsion thickness are temperature-sensitive. The room is positively pressured relative to the pressroom and the warehouse to keep paper dust and solvent vapour out. F9 filtration on the supply. The plate processor has a local extract at the developer bath to capture the mild caustic mist — small extract trunk galvanised G90 carbon adsorber on the discharge.

Press control room and quality control — climate-controlled electronics and instrumentation

The press control room — where the G7 CIP4 RTO and dryer control electronics live — is held at 22 to 24 degrees Celsius with redundant cooling. The cooling redundancy is critical because automated colour management electronics are heat-sensitive and a failure of the cooling system during a long run can crash the colour control software. Duct is galvanised G90. F7 filtration. UPS-backed AHU.

The quality control room — densitometer spectrophotometer colourimeter D50 viewing booth — is held at the same 22 to 24 degree Celsius and 50 percent relative humidity band as the pressroom because the colour measurement instruments are calibrated against the press condition. Duct is galvanised G90. F9 filtration. Slight positive pressure relative to the pressroom.

Pressure differentials and make-up air balance across the eight zones

A commercial printing plant has multiple exhaust streams running simultaneously: dryer exhaust dust extraction ink mix room extract solvent store extract pressroom return going to the AHU bindery extract foiling extract UV cure tunnel extract toner dust extract. Each one removes air from the building. That air has to be replaced — and the replacement has to be at a rate that maintains the design pressure differential between zones.

The design pressure relationships in a typical full commercial print plant are:

• Office and customer-facing zones — neutral or slight positive relative to outside (10 to 15 Pa).
• Press control room and quality control — positive relative to pressroom (5 to 10 Pa) and to office.
• Pre-press CTP — positive relative to pressroom (5 to 10 Pa) and to office.
• Pressroom — positive relative to dryer hood area warehouse bindery and ink mix room (5 to 10 Pa).
• Bindery and finishing — neutral or slight negative relative to pressroom positive relative to outside.
• Dryer hood and oven area — slight negative relative to pressroom (5 Pa) to keep solvent vapour out of the pressroom.
• Ink mix room — strong negative relative to everything else (15 to 25 Pa) to contain solvent vapour.
• Bulk solvent store — strong negative relative to everything else (15 to 25 Pa).
• Warehouse and paper store — slight positive relative to outside neutral or slight negative relative to pressroom.
• Mailroom and despatch — neutral.

Holding these differentials in operation requires a make-up air system that responds to the exhaust load. Typical configurations are dedicated make-up air handlers for the larger zones with VFD-driven supply fans modulating on a pressure-differential signal across each zone boundary. The duct system has to be sized for the design flow plus a margin with balancing dampers at every branch.

Make-up air is also the largest single heating and cooling load in the plant during the extreme weeks of the Australian year. In a Melbourne winter the make-up air heating load can exceed 1 megawatt for a large heatset plant — which is why the heat recovery off the RTO is such a valuable energy stream. Tying RTO heat recovery into make-up air pre-heat is one of the few investments that pays back in 3 to 5 years on its own before any consideration of emissions compliance.

The RTO heat-recovery business case

The single largest energy improvement available on a heatset rotogravure or solvent flexographic line is RTO heat recovery into the make-up air and the dryer combustion air. Typical savings on a mid-sized heatset commercial plant are 15 to 25 percent reduction in dryer gas consumption from preheating dryer combustion air with recovered RTO heat 30 to 50 percent reduction in winter make-up air heating gas consumption from recovering RTO heat into the make-up air pre-heat coils and 5 to 10 percent reduction in shop hot water and ink heating from lower-grade heat off the same RTO loop.

The duct work to support these recovery loops is mostly galvanised steel on the cool side and stainless on the hot side with a plate heat exchanger or a shell-and-tube heat exchanger between them. The capital cost of the recovery duct work is 10 to 15 percent of the total HVAC duct package on a heatset plant and the payback on the gas saving alone is 3 to 5 years at current Australian gas prices. With the carbon emissions reporting under ISO 14064 and the EPA framework continuing to tighten the case strengthens every year.

Acoustic targets — NC-50 and the practical implications

Commercial printing plants are noisy. A running heatset web offset press generates 90 to 95 dB(A) at the operator position; a running sheet-fed press generates 80 to 85 dB(A); a bindery line with high-speed folder and trimmer running generates 85 to 90 dB(A); a digital sheet-fed press generates 70 to 75 dB(A); the ink mix room is silent. The HVAC duct system has to fit into the noisy environment without adding measurable noise at the operator station, and into the quiet environment without dominating the soundscape.

The industry target is NC-50 maximum at the operator position from the HVAC alone on the noisy lines and NC-40 on the digital and quality control. Achieving this means supply diffusers sized for 5 to 6 metres per second face velocity maximum (not the 8 to 10 metres per second typical of commercial offices) trunk velocity 8 to 12 metres per second on supply lower on return internally lined supply duct only in the immediate run from the AHU (10 to 15 metres maximum) because acoustic liner is excluded from classified zones and from any duct that has to be cleanable and inline silencers in the supply trunk where the run is too short for natural attenuation. Vibration isolation on fan mounts and flexible connections at every AHU and exhaust fan. See the acoustic HVAC duct lining and attenuator guide for the detail on liner selection and attenuator sizing.

Fire and smoke control across the zones

A commercial printing plant has multiple fire-load zones — paper warehouse ink mix room bulk solvent store dryer and oven area pressroom bindery and finished goods warehouse. The duct system has to provide fire and smoke separation between zones in line with AS 1668.1 the National Construction Code Section J and AS 1530.4. Duct passing through a fire-rated wall has fire dampers (or smoke dampers depending on the rating) installed at the wall line certified to AS 1682 and held open by a fusible link or smoke detector. The dampers fail closed on fire and isolate the duct system.

The practical considerations for the duct contractor are fire dampers add length and weight at every wall penetration — they need access doors immediately on the non-classified side for maintenance under AS 1851. Duct passing through the dryer / oven exhaust train through a wall needs a high-temperature damper (rated for 250 degrees Celsius minimum often 400 degrees Celsius) which is a specialty item. The HVAC controls have to integrate with the fire alarm — typically a fire trip closes all dampers and shuts down all fans except dedicated smoke exhaust fans. Solvent ink and solvent store ventilation has its own interlocks — loss of exhaust ventilation triggers an ink supply isolation valve to close.

Insulation lagging and external duct

Two distinct insulation requirements operate in a commercial printing plant. The first is thermal insulation on cool ducts (chilled water supply conditioned air supply) to prevent condensation and to limit energy loss. The second is high-temperature insulation on hot ducts (dryer exhaust RTO inlet RTO outlet UV cure tunnel extract IR drying tunnel extract) to keep the gas above its dewpoint and to protect personnel from burns.

For cool ducts the standard is 50 millimetres of mineral wool with foil vapour barrier on the outside taped and sealed at joints. For chilled-water ducts in humid spaces 75 millimetres is recommended. For external supply duct on a roof run 100 millimetres of weatherproof insulation clad in galvanised sheet is standard.

For hot ducts the insulation is calcium silicate or ceramic-fibre blanket 75 to 100 millimetres thick depending on operating temperature clad in galvanised or stainless sheet metal. The cladding is the visible finish and has to seal against weather on external runs. Trace heating is installed under the insulation on any external run where the gas could drop below the dewpoint in winter — typically 30 to 40 watts per metre of self-regulating cable controlled by an ambient thermostat. The trace heating is mandatory on heatset dryer trunk in Melbourne and any colder climate; less critical in Brisbane and Perth.

Duct material selection — the boundary between galvanised and stainless

The duct material selection in a commercial printing plant is a binary decision per zone: galvanised G90 for general comfort HVAC dust extraction and lower-temperature exhaust; stainless 304 or 316L for dryer exhaust ink mix room solvent store UV and IR cure tunnel any classified zone where solvent contact is direct. Getting the boundary right is the single largest cost lever on the duct work package.

Galvanised G90 (270 grams per square metre zinc coating) is the default duct material for indoor work. G115 (345 grams per square metre) for any outdoor or roof-mounted run. Galvanised is suitable for all pressroom comfort HVAC supply and return pre-press CTP supply return and exhaust bindery and finishing comfort HVAC and the dust extraction trunk warehouse make-up air supply and return mailroom and office HVAC coldset newspaper press hall and dust extraction water-based flexographic (corrugated post-print) supply return and exhaust water-based inkjet digital web and digital sheet-fed supply return and exhaust and cool-side duct downstream of any RTO heat recovery once the gas is below 150 degrees Celsius.

Galvanised duct in a typical full commercial print plant is 70 to 80 percent of total duct linear metres and roughly 60 to 70 percent of total duct cost. The SBAL-V auto duct line produces rectangular TDF duct in galvanised at 16 to 22 metres per minute. The SBSF-1525 spiral tubeformer produces round spiral duct in galvanised at 12 to 18 metres per minute. The SBFB-1500 flat-belt spiral machine produces longer continuous spiral duct for the multi-storey return air risers in tall pressroom buildings. The SBPC1500 plasma cutter cuts the access doors clean-out hatches and custom flanges.

304 stainless is the required material for heatset web offset dryer hood to RTO inlet (hot solvent-laden condensable) rotogravure dryer to RTO trunk solvent flexographic dryer to RTO trunk UV ink cure tunnel ozone extract IR ink drying tunnel exhaust inline coating line VOC exhaust ink mix room extract bulk solvent store extract sheet-fed UV exhaust if the UV tower runs above 200 degrees Celsius surface temperature ink and solvent store extract where the chemistry is corrosive or where condensation is expected spray booth exhaust under NFPA 33 and any duct serving an oven exhaust under NFPA 86.

316L stainless is preferred where the ink chemistry includes chloride compounds or where condensation is expected in the duct over a 15-year service life. The cost differential between 304 and 316L is roughly 25 to 40 percent at sheet level so the choice matters on a large plant.

Seam construction on stainless dryer duct is TIG-welded full-penetration longitudinal seam with the root side cleaned and passivated. Snap-lock or Pittsburgh seam is unacceptable on this duty — the seam has to hold at temperature and at slight positive or negative pressure relative to the surrounding building. The seam welder on the duct fabrication shop floor has to be capable of producing TIG seams on sheet stainless at a rate that supports the project schedule which constrains the fabrication shop selection. The SB-ZF1500 stitchwelder is the SBKJ machine that meets this duty cycle reliably — stainless coil from 0.4 to 1.5 millimetres thick fed continuously with weld speed adjusted by control panel.

Hazardous area duct work and Ex-rated fittings — the eight rules

Where a commercial printing plant operates with solvent inks — heatset web offset rotogravure solvent flexographic UV ink ink mix room bulk solvent store — the duct work in the affected zones is part of an installation that has to comply with AS/NZS 60079.10.1 (area classification) and AS/NZS 60079.14 (electrical installation). The duct itself is generally bonded metal earthed continuously to a common earth bar but the fans dampers sensors lighting and control gear in the classified zone all have to be Ex-rated.

The practical consequences for the duct contractor are eight rules:

1. Earthing — every duct section is bonded across joints with a continuity strap and the entire system is earthed to a single ground point per zone. Plastic flange gaskets are excluded; conductive gaskets specified.
2. Ex-rated fans — exhaust fans in classified zones are Ex-e or Ex-d motors with corresponding terminal boxes. The fan housing is metal not fibreglass. Bearing temperature monitoring is mandatory on the larger fans. The impeller is spark-resistant (typically aluminium or stainless with brass shroud).
3. Ex-rated dampers — actuators on dampers in classified zones are Ex-rated electric or pneumatic. Spring-return pneumatic actuators are common because they fail safe to a known position on air loss.
4. Sensor selection — temperature pressure and flow sensors in classified zones are Ex-rated with intrinsically safe wiring back to a barrier panel in the safe area.
5. Cleanouts — clean-out doors on solvent duct are sealed with conductive gaskets and bonded across the seal. No internal liners.
6. Fire-rated penetrations — duct passing through a fire-rated wall between classified and non-classified zones uses an approved fire-stop sleeve that maintains both the fire rating and the bonding continuity.
7. No PVC and no fabric — PVC duct and fabric duct are excluded from every classified zone under AS/NZS 60079. The duct in a classified zone is always bonded metal.
8. Spark detection in the duct — a spark detector and water-spray extinguisher in the duct at the inlet to any baghouse on combustible dust (paper dust toner dust) under NFPA 660 and at the inlet to any RTO on solvent vapour. The detection-and-extinguishing chain is the difference between a contained near-miss and a baghouse explosion.

The duct fabrication shop does not have to be Ex-certified to fabricate duct for a classified zone but the installation contractor does have to understand the discipline — and the duct fabrication has to support it through correct bonding tabs no internal acoustic liners and the right gasket selection. The SBAL-V SBSF-1525 SBFB-1500 SB-ZF1500 and SBPC1500 combination produces bonded earth-ready duct out of the box for both galvanised and stainless coil.

The SBKJ fabrication shop for a major commercial printing project

A duct contractor tendering for a major commercial printing project needs a fabrication line that can switch between materials gauges and seam types within a single shift. A typical large commercial printing HVAC project mix is 70 to 80 percent galvanised G90 spiral and rectangular duct 10 to 20 percent stainless 304 or 316L for dryer exhaust ink mix room solvent store UV and IR cure tunnel and inline coating extract and a small fraction of high-temperature alloy duct for the hottest oven runs.

The SBKJ machine configuration we recommend for a contractor serving the full commercial printing depth is six machines:

• SBAL-V Auto Duct Line in the galvanised + stainless option — handles 0.6 to 1.5 millimetres thickness 1,000 to 1,300 millimetres coil width with both galvanised and stainless coil change-over without changing the tooling. Output 16 to 22 metres per minute of rectangular TDF duct on galvanised; 12 to 15 metres per minute on stainless. Single-shift capacity covers the comfort HVAC and bindery duct demand on a major project. Spec verbatim from the SBKJ machines catalogue.
• SBSF-1525 Spiral Tubeformer — round spiral duct from 100 to 1,500 millimetres diameter for the pressroom supply trunks the dust extraction risers and the digital hall supply. Galvanised and stainless coil compatible.
• SBFB-1500 Flat-Belt Spiral — longer continuous spiral duct for the multi-storey return air risers in tall pressroom buildings the warehouse make-up air risers and the ink mix room dedicated extract riser. Galvanised and stainless coil compatible.
• SB-ZF1500 Stitchwelder — TIG-quality longitudinal seam welder for stainless dryer exhaust UV cure tunnel plenums RTO inlet plenums and ink mix room extract. Stainless coil 0.4 to 1.5 millimetres thick. Full-penetration root protected post-weld passivated.
• SBPC1500 Plasma Cutter — access door openings clean-out hatches custom flanges and the trim work on the SBAL-V output. Galvanised and stainless coil compatible.
• SBLR-600 Manual Welder — repair work field weld-ups expansion joint welding and the on-site rectification welding that every project eventually needs.

This six-machine combination covers the full duct work scope on a major commercial printing project from a single fabrication floor. The contractor avoids subcontracting the stainless work to a specialty shop (which adds 30 to 50 percent cost on stainless line items and lengthens the project schedule) and avoids the alternative of running a single dual-purpose line at lower productivity for galvanised work. We have helped contractors in Sydney Melbourne Brisbane Adelaide and Perth set up this configuration over the last decade. The combination is also in service with commercial printing duct contractors in 60+ export markets through the SBKJ engineering network.

Spark-resistant fans IECEx Ex-d ATEX-rated motors and conductive gaskets are mandatory for the ink mix room Zone 2 extract the solvent store Zone 1 envelope the UV ink cure ozone duct (NFPA 660 on the paper dust trunk and the toner dust trunk on the digital sheet-fed hall) and any other classified zone. The fabrication shop produces the duct that connects to those fans — bonded earth-ready throughout — and the installation contractor commissions the fans the actuators and the spark detection as part of the AS/NZS 60079.14 electrical install.

Lead time sequencing and project-stage duct delivery

A full commercial printing plant duct project typically runs in three stages over 10 to 18 months from contract to commissioning:

• Stage 1 — foundation and superstructure (months 1 to 5). Duct routing is fixed at this stage but no duct is on site yet. The fabrication shop is sizing materials and ordering coil. The dryer exhaust stainless coil order is the long-lead item — 12 to 16 weeks for 316L sheet to land in an Australian port. The ink mix room stainless coil order is also long lead because the volumes are small and the orders go on the back of the larger stainless order.
• Stage 2 — duct installation (months 5 to 14). The duct goes in zone by zone usually starting with warehouse and office HVAC (because the ceiling is up first) then bindery and pre-press CTP then pressroom proper then UV cure tunnel and IR drying tunnel then dryer trunk and RTO inlet then ink mix room and bulk solvent store. The stainless dryer trunk is the last duct in because it ties to the press and oven which are commissioned late in the schedule.
• Stage 3 — commissioning and balancing (months 14 to 18). Air balancing across zones pressure differential testing smoke testing for fire dampers witness testing of dryer exhaust with the RTO running ozone testing of UV cure tunnel extract ink mix room ventilation rate testing and combustible dust testing of the bindery trunk under NFPA 660. EPA compliance test on the stack. Final acceptance.

The duct contractor's exposure is concentrated in stages 2 and 3. A delay in stainless dryer trunk delivery delays the whole press commissioning — and on a heatset commercial site every week of delay on press commissioning is a six-figure revenue loss to the operator. The fabrication shop that can hold the stainless schedule is the one that wins the next project.

Common failure modes — what we see in the field

We commission commercial printing duct projects regularly across the Australian east coast and the failure modes tend to repeat. The eight most common are:

1. Galvanised duct on the dryer exhaust trunk. Someone has value-engineered the stainless out of the heatset trunk. The duct survives commissioning runs for 18 months and then the seams start failing where solvent condensation has stripped the zinc. Repair requires shutting the press down for a week and replacing the trunk with stainless after the fact.
2. Shared duct between dryer exhaust and pressroom return. A short-cut on the design has tied the pressroom return into the dryer exhaust trunk to save a separate fan. Result is solvent vapour back into the pressroom on any pressure swing and the AHU coils contaminated within months.
3. No expansion joints on the dryer trunk. A 30-metre dryer trunk that sees a 250 degree Celsius swing every shift expands and contracts by 80 to 100 millimetres cumulatively. Without expansion joints the duct cracks at the first elbow.
4. Inadequate dust extraction at the folder. The bindery dust trunk is undersized and the transport velocity drops below 15 metres per second. Paper dust settles in the duct eventually blocks it and the static buildup on the residual flow becomes a fire risk under NFPA 660.
5. Wrong filtration on the pressroom supply. The supply air filtration is M5 or F5 (typical commercial spec) rather than F7 or F9 (industry standard for commercial printing). The result is airborne dust on wet ink and rejected sheets — the cost of the rejected work in a single month often exceeds the cost of upgrading the filtration for the life of the AHU.
6. No spark detection on the ink mix room extract. A spark detector at the duct inlet to the Ex-d fan is the only line of defence between an ignition event in the room and a fan explosion. Skip it to save AUD 8,000 and the eventual incident costs the operator AUD 2 to 5 million in plant damage and downtime.
7. Internal acoustic liner in a classified zone. Someone has lined the ink mix room extract duct for noise control. Acoustic liner holds static charge and is excluded from classified zones under AS/NZS 60079. The remedial work is total duct replacement after the AS/NZS 60079.17 inspection picks it up.
8. Ozone extract from the UV cure tunnel discharged near an air intake. The UV cure tunnel discharges ozone at concentrations that need a stack height calculated by AS 3580 dispersion modelling. Discharging at low level near an air intake on a neighbouring building (or worse the office air intake on the same building) creates a recirculation loop that exposes office workers to ozone above the 0.1 ppm WES. Remedial work is stack extension or relocation.

All eight are preventable at design stage. The cost of catching them at design is two or three engineer days of review. The cost of catching them at commissioning is rework. The cost of catching them six months into operation is a production shutdown and in two of the eight cases an injury or fatality. The duct contractor that walks the design with the operator and the consulting engineer at the 60 percent design milestone catches most of them. The duct contractor that turns up at site to install duct off a drawing pack without a design walk catches none of them.

The commercial-printing duct-contractor profile that wins these projects

The duct contractors that win the major commercial printing projects in Australia tend to share four characteristics:

• Dual-material fabrication capability. The shop can produce galvanised G90 rectangular and spiral and 304 / 316L stainless rectangular and spiral on the same floor in the same week with the same crews. This is the SBAL-V plus SBSF-1525 plus SB-ZF1500 combination above.
• Stitchwelding capacity for stainless. The shop has a stitchwelder rated for 0.4 to 1.5 millimetres stainless coil running TIG-quality full-penetration longitudinal seam at a metre rate that holds the project schedule. The SB-ZF1500 is the SBKJ machine that meets this duty.
• AS/NZS 60079 awareness. The shop produces bonded earth-ready duct with conductive gasket flanges no internal liners and the documentation pack that the installation contractor needs to file the AS/NZS 60079.14 install certification.
• RTO inlet plenum experience. The shop has previously fabricated an RTO inlet plenum or a similar custom stainless assembly — usually as a sub-project on a previous commercial printing or chemical plant build — and can produce drawings and weld procedures to support the next one.

The contractors that consistently win the IVE Group Argyle Group McPhersons Ligare Bolton Imaging Visy Orora Amcor Pact Detmold Multi-Color Are Media News Corp Nine Publishing and ACM projects all show three or four of these characteristics. The contractors that lose the work are typically galvanised-only shops without stitchwelding capacity — perfectly competent on the 70 percent of the duct that is galvanised but unable to deliver the 20 to 30 percent that is stainless. Subcontracting the stainless adds cost lengthens schedule and adds a coordination overhead that the operator does not want to absorb. The integrated dual-material shop wins by default.

Sustainability ISO 14064 carbon accounting and the next decade

The commercial printing sector has been under continuous energy and emissions pressure for two decades. Heatset is the most exposed because the dryer is the largest single energy load in the plant and the most directly tied to emissions. Rotogravure and solvent flexographic are equally exposed because the RTO consumes natural gas to maintain the destruction temperature. Coldset newspaper sheet-fed digital and water-based flexographic are less exposed but still under cost pressure from rising electricity and gas prices and the carbon accounting framework imposed by the larger publishers and brand owners on their print procurement.

ISO 14064 carbon accounting is the framework most major Australian publishers and brand owners are now imposing on their commercial print suppliers. Are Media News Corp Nine Publishing the supermarket retailers (Woolworths Coles Aldi Costco) the major FMCG brands (Unilever Nestle PepsiCo Mondelez) the alcohol majors (CUB Lion Asahi Treasury Wine Estates) and the personal care majors (P&G Colgate-Palmolive L'Oreal) all run procurement requirements that ask the printer to report Scope 1 and Scope 2 emissions per unit of printed product. The printer has to measure and report. The largest single lever the printer has on Scope 1 emissions is RTO heat recovery. The largest single lever on Scope 2 emissions is HVAC efficiency. The duct work is on the critical path for both.

The next decade of commercial printing HVAC will be dominated by three trends. First the gradual replacement of gas-fired drying with electric resistance and infrared drying — the duct material implications are small (still stainless on the hot side) but the heating loads on the make-up air during the transition period are large. Second the replacement of mercury vapour UV lamps with UV LED — the duct material implications are minor (still stainless on the ozone extract because UV LED at high intensity still generates some ozone in the air gap) but the heat loads on the cure tunnel drop substantially. Third the wider adoption of digital printing for short and medium runs displacing some of the sheet-fed offset volume — the duct mix shifts toward more galvanised and less stainless but the overall duct linear metres per plant stay similar because the digital halls run more presses per square metre than the offset halls.

Worked example — a 12,000 square metre commercial printing plant in regional Victoria

To make the framework concrete consider a 12,000 square metre commercial printing plant in regional Victoria — say Maryborough Bendigo Ballarat or Geelong — running a single heatset web offset press a pair of sheet-fed B1 offset presses an HP Indigo digital sheet-fed two narrow-web UV flexographic label lines a perfect-binding line a saddle-stitching line a small rotogravure deck for flexible packaging a CTP plate room an ink mix room a bulk solvent store a 4,000 square metre paper warehouse and a 1,500 square metre finished goods warehouse. The plant runs two shifts six days a week. The HVAC duct package on a project of this scale lands at approximately AUD 4 to 6 million in fabricated duct and installation labour.

The duct linear metres break down approximately as 4,800 metres of galvanised G90 rectangular TDF duct on the pressroom comfort HVAC bindery comfort HVAC warehouse make-up office HVAC mailroom and CTP comfort. 2,400 metres of galvanised G90 spiral duct on the pressroom supply trunks the bindery dust extraction trunk the warehouse make-up air supply and the multi-storey return air risers. 600 metres of 304 stainless rectangular and spiral on the heatset dryer trunk the RTO inlet plenum the UV cure tunnel extract the IR drying tunnel exhaust and the ink mix room extract. 200 metres of 316L stainless on the rotogravure dryer trunk and the bulk solvent store extract. 60 access doors clean-out hatches and custom flanges produced on the SBPC1500 plasma cutter. 12 fire dampers and 6 high-temperature dampers at the wall penetrations. Approximately 1,800 hours of stitchwelding on the stainless work produced on the SB-ZF1500.

The fabrication shop sequence is the SBAL-V running galvanised G90 coil during the day shift for the rectangular duct the SBAL-V running stainless coil during the night shift for the smaller stainless rectangular runs the SBSF-1525 and SBFB-1500 running galvanised spiral during the day shift and the SB-ZF1500 stitchwelding the stainless coil through three concentrated weeks during stages 2 and 3 of the project. The SBPC1500 cuts the trim work and the access door openings as a constant low-volume task. The SBLR-600 handles the on-site weld-ups during install.

A duct contractor with this SBKJ machine combination delivers the full project from a single fabrication floor in 14 to 16 months from contract signature to commissioning. The same contractor without the SB-ZF1500 subcontracts the stainless to a specialty shop in Sydney or Melbourne adding 30 to 50 percent cost on the stainless line items and 4 to 6 weeks to the project schedule. The same contractor without the SBFB-1500 fabricates the long-run spiral on a shorter machine in multiple sections adding install labour and creating joint count exposure. The integrated six-machine SBKJ shop is the configuration that holds the AUD 4 to 6 million budget the 14 to 16 month schedule and the quality bar that lets the operator commission without remedial work.

What we deliver to commercial-printing duct contractors

SBKJ supplies the fabrication machinery — auto duct lines spiral tubeformers stitchwelders flat-belt spirals plasma cutters manual welders and the supporting tooling — that lets a duct contractor or fabrication shop build commercial printing plant duct work to the specs in this guide. We do not sell the duct itself; we sell the machines that make it. Our standard commercial printing configuration is the six-machine combination listed above: SBAL-V auto duct line in the galvanised + stainless option SBSF-1525 spiral tubeformer SBFB-1500 flat-belt spiral SB-ZF1500 stitchwelder SBPC1500 plasma cutter and SBLR-600 manual welder. The six machines together cover the full duct scope on a major commercial printing HVAC project from a single fabrication floor.

Our engineering team is based in Box Hill North VIC — about 15 kilometres from the Orora Box Hill HQ and within a 20-minute drive of the IVE Group Mount Waverley plant. We have walked most of the major commercial printing sites in Victoria New South Wales and Queensland over the last decade. If you are quoting a commercial printing HVAC duct package — heatset web offset sheet-fed commercial digital flexographic rotogravure label magazine book or packaging — we are happy to walk through the duct scope with one of our engineers and recommend the right machine specification for your shop. Our engineers reply within 12 hours and the discussion is always with a mechanical engineer rather than a salesperson. We will be at ARBS 2026 in Sydney on the Australia Ducting Pty Ltd stand 236 — the SBKJ engineering team will be on stand for the duration of the show and the conversation is open to any duct contractor in the commercial printing space.

Discuss your commercial printing duct fabrication setup with an SBKJ engineer →

FAQ

How is a full commercial printing plant different from a newspaper-only plant in HVAC terms?

A newspaper-only plant runs three or four HVAC zones — coldset press hall paper dust extraction warehouse and office. A full commercial printing plant runs eight to twelve HVAC zones simultaneously including heatset dryer trunk UV cure tunnel rotogravure RTO inlet ink mix room bulk solvent store pressroom proper bindery and finishing CTP plate room and several office zones. The chemistry depth is the difference — ink solvent ozone isocyanate UV light paper dust toner dust hot melt adhesive IR heat all in one building under one duct system.

What WES contaminants drive duct design in a commercial printing facility?

Isocyanate at 0.005 ppm short-term exposure limit on any PU UV ink chemistry — the lowest WES in the building and the design driver for the cure tunnel extract. Ozone at 0.1 ppm from UV cure tunnels and toner corona discharge. Ink solvents — toluene 50 xylene 50 MEK 200 IPA 400 acetone 500 ethyl acetate 300 glycol ether 50 ppm. Respirable paper dust at 10 milligrams per cubic metre with trace respirable crystalline silica at 0.05 milligrams per cubic metre. Toner powder at 5 milligrams per cubic metre inhalable and 1 milligram per cubic metre respirable with rare-earth filler (cerium praseodymium neodymium lanthanum samarium europium) on colour cartridges. UV light at 365 nanometres around any UV cure tunnel.

Which Australian standards apply to commercial printing plant ductwork?

AS 1668.2 mechanical ventilation AS 4254 ductwork construction AS 1530.4 fire-resistance AS 1851 fire-protection servicing AS 1657 fixed platforms AS/NZS 60079.10.1 and 60079.14 hazardous areas AS 1940 flammable and combustible liquids AS 3957 dust ventilation AS 1318 industrial chimneys AS 4036 and 4037 boilers and pressure vessels AS 4801 OHS management. NCC Class 8 industrial Class 5 office Class 7b warehouse. NFPA 33 spray application NFPA 86 industrial ovens NFPA 660 combustible dust referenced as best practice. ASHRAE Applications Ch 33 industrial ventilation Ch 38 industrial drying. ISO 12647 colour management ISO 14064 carbon accounting.

What duct material is correct for each zone in a commercial printing plant?

Galvanised G90 for pressroom comfort HVAC pre-press CTP bindery and finishing warehouse and paper store mailroom office coldset newspaper press hall water-based flexographic water-based inkjet digital sheet-fed and any cool-side duct downstream of an RTO heat exchanger. Roughly 70 to 80 percent of the total duct linear metres. 304 stainless for heatset web offset dryer trunk rotogravure RTO inlet solvent flexographic dryer UV cure tunnel ozone extract IR drying tunnel exhaust inline coating VOC exhaust ink mix room extract and bulk solvent store extract. 316L stainless preferred where the ink chemistry includes chloride or where condensation is expected.

How does the ink mix room ventilation work and why does it matter?

The ink mix room is the small room (20 to 60 square metres) where solvent water-based and UV inks are weighed blended and tinted. Classified Zone 2 under AS/NZS 60079.10.1 with a Zone 1 envelope around the decanting station. AS 1940 secondary containment around every drum spark detection and fire suppression. Ventilation rate 6 to 10 air changes per hour minimum on continuous extract from low level (solvent vapour is denser than air). Ex-d ATEX-rated centrifugal fan with spark-resistant impeller in 304 stainless. Bonded earthed stainless duct fabricated on the SB-ZF1500 stitchwelder. Discharge stack to AS 1318 and AS 3580 dispersion modelling. Getting this room right is the difference between an insurable plant and an uninsurable plant — every solvent ink fire on record in the Australian commercial print sector has started in the ink mix room.

What does an SBKJ duct fabrication shop look like for a commercial printing project?

Six machines on one floor. SBAL-V auto duct line in galvanised plus stainless option for rectangular TDF duct. SBSF-1525 spiral tubeformer for round spiral 100 to 1,500 millimetres. SBFB-1500 flat-belt spiral for long continuous risers. SB-ZF1500 stitchwelder for stainless dryer trunk and ink mix room extract. SBPC1500 plasma cutter for access doors and custom flanges. SBLR-600 manual welder for on-site weld-ups. The combination covers the full duct scope on a major commercial printing project from a single fabrication floor.

How does ISO 12647 colour management affect the pressroom HVAC specification?

ISO 12647 sets the target conditions for the substrate the ink the press and the operating environment for colour management. The operating environment is held at 22 to 24 degrees Celsius dry bulb and 50 percent relative humidity within plus or minus 2 degrees and plus or minus 5 percent on standard work and plus or minus 1 degree and plus or minus 5 percent on colour-critical work. The HVAC duct delivers conditioned supply at 18 to 20 degrees Celsius off the diffuser through F7 or F9 filtration with steam or evaporative humidification on the supply in winter and dehumidify-and-reheat on the AHU coil in summer. Galvanised G90 spiral on the supply rectangular TDF on the return.

What NFPA standards are referenced for paper dust and toner dust collection?

NFPA 660 the consolidated combustible dust standard replacing NFPA 654 and the related family. Paper dust at low humidity is a recognised combustible dust historically Class II Group G. Toner powder is also a combustible dust. The dust trunk has explosion venting on the collector body isolation devices on the inlet duct to prevent flame propagation back into the building bonded earthed metal duct throughout no flexible duct and a housekeeping regime that holds dust accumulation below the threshold layer thickness. AS 3957 sets the design framework for the duct sizing and capture velocity in the Australian context with NFPA 660 as the best-practice overlay.