Cattle Feedlot, Piggery, Poultry Broiler, Egg Layer and Intensive Livestock CAFO HVAC Duct Guide

Why intensive livestock CAFO HVAC is its own engineering category

Intensive livestock CAFO (Concentrated Animal Feeding Operation) is one of the most under-appreciated multi-zone HVAC envelopes in the Australian primary industry sector. A modern integrated cattle feedlot at JBS Australia Beef City QLD — carrying 75,000 to 90,000 head of cattle on feed at peak season, with an attached feed prep mill processing 1,000 tonnes of ration per day, an attached abattoir slaughtering 3,400 head per day, an attached rendering plant processing slaughter byproduct, an attached composting and effluent management envelope, and an on-site post-slaughter cold chain with ammonia refrigeration — runs perhaps eighteen to twenty-two distinct climatic and hazardous-area envelopes inside one site boundary. The grain reception silo at Zone 21 dust hazardous area; the hammermill and pellet mill external at Zone 22 with respirable grain dust at the operator interface; the ration mixer and ribbon-blender batching with feed dust capture; the bulk feed delivery truck loading bay with fugitive dust; the open feedlot pen at 30,000 to 90,000 head with fugitive ammonia, hydrogen sulfide, methane and odour emission to the surrounding airshed; the runoff dam, effluent pond and sediment trap with anaerobic decomposition; the abattoir cross-over post-slaughter with ASHRAE 170 ventilation cascade from lairage to stunning to sticking to scalding to dehiding to evisceration to chilling; the IQF freezer and cold store at minus 25 to minus 35 degrees Celsius with R-717 ammonia refrigeration; the rendering cooker at 100 to 130 degrees Celsius discharging into a chemical scrubber and biofilter or RTO; and the ASHRAE 170 biosecurity isolation envelope for mass mortality response during HPAI H5N1 bird flu, ASF African Swine Fever or FMD Foot-and-Mouth Disease outbreaks.

Each envelope has its own duct material grade, sealing class, pressurisation differential, hazardous area zone rating and biosecurity regime. Each is governed by a different combination of AS 4485 (Design and Operation of Australian Piggery and Poultry Buildings), AS 5807 (Free Range Egg Standards 2017), AS 1668.2 (mechanical ventilation), AS 4254 (ductwork), AS/NZS 60079 (hazardous area classification — Zone 0/1 biogas methane, Zone 21/22 grain dust, Class I Zone 2 ammonia plant), AS 3957 (dust hazard), NFPA 660 (the 2025 consolidated combustible particulate solids standard), NFPA 853 (anaerobic digester biogas guidance), NFPA 68 (deflagration venting), NFPA 69 (explosion protection), AS/NZS 1677 (ammonia refrigeration), AS/NZS 2243.3 (laboratory biosafety PC2 for veterinary diagnostic), ASHRAE 170 (ventilation of health care facilities, referenced for biosecurity isolation), the ALFA Cattle Feedlot Code of Practice, the APL Pig Welfare Code, the ACMF Chicken Welfare Code, the Biosecurity Act 2015 framework, the AHA Animal Health Australia response framework, the APVMA Australian Pesticides and Veterinary Medicines Authority chemical registration framework, the AQIS Australian Quarantine and Inspection Service export certification framework and the RSPCA welfare framework. The grain dust deflagration risk is the single highest acute hazard in the feed prep mill; the ammonia worker exposure dominates inside the piggery shed and the poultry broiler shed; the hydrogen sulfide acute fatality risk dominates around the manure pit, slurry pit, effluent lagoon and anaerobic digester; the methane explosion risk dominates around the biogas system; the HPAI and ASF biosecurity isolation envelope is the controlling parameter under the AHA framework; and the fugitive odour emission from the feedlot pen, the piggery shed and the broiler shed is the dominant regulatory pathway under the NSW EPA POEO, the VIC EPA and the QLD DES.

SBKJ Group has supplied auto duct production lines, spiral tubeformers, stitchwelders, plasma cutters and longitudinal seam welders into the Australian intensive livestock sector. Our engineers from the Box Hill North VIC office have walked the JBS Beef City feed prep mill at Toowoomba QLD, the Mort & Co Grassdale ration mill, the Smithfield Cattle Company NSW ration prep, the SunPork Caboolture piggery hub, the Rivalea Corowa breeder and grower-finisher network, the Linley Valley Pork WA processing, the Inghams broiler grow-out shed network, the Baiada Steggles broiler and processing, the ProTen contract grower farms, the Cordina Chicken Farms NSW, the Hazeldenes VIC operation, the Pace Farm Beechwood and Berkshire Park egg layer barns, the Sunny Queen Australia free range layer, the Pirovic Egg Farms and Farm Pride, the Ridley Corporation integrated pellet mill network, the Coprice Riverina rice-based mill and the Lienert Australia premix site. We have seen what fails on a fifteen-year duct lifecycle in the corrosive ammonia, hydrogen sulfide and chloride exposure of intensive livestock, what the ALFA accreditation audit flags first on a feedlot, what the APL Pig Welfare audit checks on a piggery, what the ACMF Chicken Welfare audit checks on a broiler farm, what the AS 5807 Free Range Egg Standards audit checks on a layer farm, what the AHA Animal Health Australia inspector asks during an HPAI or ASF response simulation, and what the state EPA Air Quality officer asks about during a community-complaint odour investigation. This guide is written against that field experience.

The Australian intensive livestock sector — operators, sites and production scale

Before specifying HVAC ductwork for any intensive livestock site the engineering team has to know the operator, the site location, the production scale, the species and the regulatory envelope. The Australian intensive livestock sector is dominated by a small number of vertically integrated multinationals and national champions across cattle feedlot, piggery, poultry broiler and egg layer, with peak industry bodies (ALFA, APL, ACMF) and the AHA Animal Health Australia framework overlaying.

Cattle feedlot — ALFA, JBS Australia, Teys, Stanbroke, Mort & Co and the major operators

ALFA Australian Lot Feeders Association is the peak industry body for the Australian cattle feedlot sector with the National Feedlot Accreditation Scheme NFAS as the binding accreditation framework. The ALFA Cattle Feedlot Code of Practice is the single most important reference document for any Australian feedlot HVAC and effluent management specification. NFAS accreditation is a market-access prerequisite for the supermarket beef supply chain in Australia and for the export beef trade.

JBS Australia is the largest integrated beef processor in Australia and one of the largest feedlot operators in the southern hemisphere. The Beef City QLD site near Toowoomba carries 75,000 to 90,000 head on feed at peak season and is the second-largest single feedlot in Australia. The Yardea SA site carries approximately 25,000 head and serves the South Australian export beef supply chain. The Caroona NSW site near Quirindi carries approximately 25,000 head. The Riverina QLD Mungindi-area feedlot adds further capacity. Each JBS feedlot site is supported by an attached feed prep mill processing 500 to 1,000 tonnes of ration per day, an attached abattoir (Beef City processes 3,400 head per day, one of the largest single-site beef processing facilities globally), a rendering plant, an effluent management envelope and an on-site post-slaughter cold chain.

Teys Australia is the second-largest integrated beef processor in Australia with a joint venture history with Cargill and major feedlot capacity across the Tropical North Queensland, Brisbane and southern New South Wales footprint. The Teys Beenleigh QLD abattoir, the Teys Wagga Wagga NSW abattoir, the Teys Naracoorte SA abattoir, the Teys Tamworth NSW abattoir and the supporting feedlot network constitute the Teys network. The Teys feedlots include Charlton QLD, Condamine QLD and Riverina southern feedlot capacity.

Stanbroke Pastoral Company is one of the largest privately-owned beef producers and feedlot operators in Australia with major Queensland and Northern Territory pastoral country and the Stanbroke feedlot near Toowoomba with significant capacity. Mort & Co is the largest privately-owned dedicated feedlot operator in Australia with the Grassdale QLD feedlot near Dalby carrying 75,000+ head (the largest single feedlot in Australia at peak capacity), the Pinegrove NSW feedlot near Inverell and supporting capacity. Smithfield Cattle Company operates the Smithfield feedlot in NSW with significant capacity in the northern New South Wales and southern Queensland feedlot belt. Killara Feedlot near Quirindi NSW carries approximately 18,000 head and serves the southern New South Wales export beef supply chain. Rangers Valley Feedlot in northern NSW specialises in the long-fed marbled premium Wagyu and Black Angus market with 360-day grain-feeding programmes for the premium export beef supply.

Piggery — APL, SunPork, Rivalea (now SunPork), George Weston Foods, Linley Valley Pork

APL Australian Pork Limited is the peak industry body for the Australian pork sector with the APL Pig Welfare Code as the binding welfare reference and the APL Australian Pork Industry Quality Assurance Programme APIQ as the binding quality assurance framework. SunPork Group is now the largest integrated pork producer in Australia following the acquisition of Rivalea Australia, with operations spanning Caboolture QLD (corporate headquarters and pork processing), Berrimah NT (top-end piggery operation), Hopetoun VIC (Victorian Mallee piggery operation) and Yongala SA (South Australian piggery operation), with the legacy Rivalea Corowa NSW breeder and grower-finisher operation now under the SunPork umbrella. SunPork is Australia's biggest pork producer with vertical integration from breeder through grower-finisher to processing.

George Weston Foods operates the Don Smallgoods and Primo Smallgoods brands with associated piggery supply and pork processing capacity. Linley Valley Pork in Western Australia is the largest pork processor in WA and serves the Western Australian and export pork market. The integrated piggery envelope at SunPork Caboolture, the Rivalea Corowa breeder unit and the Linley Valley Pork processing line all run AS 4485 piggery design with tunnel ventilation, evaporative cool cell pad cooling, farrowing crate climate control at 28 to 30 degrees Celsius for the suckling piglet, weaner room at 26 to 28 degrees, grower-finisher at 22 to 18 degrees, breeder at 18 to 22 degrees, and ASHRAE 170 biosecurity isolation for ASF African Swine Fever response and AI artificial insemination room.

Poultry broiler — ACMF, Inghams, Baiada, ProTen, Cordina, Hazeldenes

ACMF Australian Chicken Meat Federation is the peak industry body for the Australian chicken meat sector with the ACMF Chicken Welfare Code as the binding welfare reference. Inghams Group (ASX:ING) is the largest integrated poultry processor in Australia with vertical integration from breeder farm through hatchery through broiler grow-out through processing through further processing and distribution. The Inghams network spans Sydney NSW (Lansvale and the supporting western Sydney broiler shed network), Brisbane QLD, Melbourne VIC, Adelaide SA and Perth WA with broiler processing plants and supporting grow-out shed networks. Inghams runs the Ross 308 and Cobb 500 broiler genetics with 38 to 45 day grow-out cycles and post-processing further processing including portioning, marinating, cooking and IQF freezing.

Baiada Poultry operates the Steggles brand and is the second-largest integrated poultry processor in Australia with processing plants in NSW (Hanwood, Tamworth), QLD (Pinkenba) and supporting grow-out shed networks. ProTen is Australia's largest contract broiler grower network with broiler shed capacity supplying both Inghams and Baiada. Cordina Chicken Farms operates the Cordina brand from Girraween NSW with associated grow-out and processing capacity. Hazeldenes Chicken Farm operates from Lockwood VIC with the Hazeldenes free range and conventional broiler brands. Bartter Enterprises historically operated the Steggles brand before the Baiada acquisition.

The broiler shed envelope is the largest single-species intensive livestock envelope by air volume in Australia — a typical Inghams broiler shed is 150 metres long by 18 metres wide carrying 40,000 to 60,000 birds per cycle with tunnel ventilation at 8 to 12 metres per second longitudinal air velocity, 30 to 50 Pa negative pressure, Munters cool cell pad evaporative cooling on the inlet, and 8 to 12 variable-speed extract fans at the discharge end. Chick brooder at day-old to day-7 runs at 32 to 34 degrees Celsius; grow-out at day-8 onward runs at 18 to 24 degrees Celsius depending on bird age and ambient. Humidity is held at 50 to 70 percent RH. Big Dutchman, Vencomatic and Munters are the dominant equipment suppliers globally and on Australian sites.

Hatchery — Inghams, Baiada, ProTen breeder farm and incubator

The poultry hatchery is a specialist biosecure cleanroom-adjacent envelope upstream of the broiler grow-out shed. Inghams operates major hatcheries at Bringelly NSW, Pakenham VIC, Wanneroo WA and supporting locations. Baiada operates major hatcheries supporting the Steggles network. The hatchery envelope includes the breeder farm (parent stock), the egg collection and grading, the setter incubator (18 days at 37.5 degrees Celsius and 55 to 60 percent RH), the hatcher (3 days at 37.0 degrees and 65 to 70 percent RH), the chick sexing and vaccination station (in-ovo Marek's disease injection, post-hatch coccidiosis vaccination), the chick despatch envelope and the egg breakage and sanitation waste stream. The hatchery is engineered to AS 4485 plus AS/NZS 2243.3 PC2 biosafety reference and operates with HEPA-filtered supply and dedicated extract to manage Salmonella, Pullorum, Marek's disease and HPAI biosecurity. NatureForm, Petersime and Pas Reform are the dominant incubator equipment suppliers.

Egg layer — Pace Farm, Sunny Queen, Pirovic, Farm Pride, AS 5807 Free Range Egg Standards 2017

The Australian egg layer sector operates under the Free Range Egg Standards 2017 (codified into AS 5807) which set a maximum of 10,000 birds per hectare for any product labelled "free range" and require information disclosure on outdoor stocking density. Pace Farm is the largest egg producer in NSW with operations at Beechwood NSW (north coast), Berkshire Park NSW (western Sydney), Manning Valley NSW and supporting locations — the Pace Farm portfolio covers free range, barn and caged production. Sunny Queen Australia is the largest egg producer in QLD with operations across the Queensland egg layer belt and significant free range, caged and barn capacity — Sunny Queen runs both the conventional caged colony envelope and the AS 5807 free range envelope and is one of the largest single-egg-supply brands in the Australian supermarket channel. Pirovic Egg Farms operates significant NSW egg layer capacity. Farm Pride Foods operates the Farm Pride brand with significant Victorian egg layer capacity and is publicly listed. The egg layer envelope spans free range (outdoor access with maximum 10,000 birds per hectare under AS 5807), barn (indoor with floor housing and litter), and caged colony (multi-tier cage system).

Animal feed mill — Ridley Corporation, Coprice Riverina, Riverina Stockfeeds, Lienert

Ridley Corporation (ASX:RIC) is Australia's largest integrated livestock feed manufacturer, operating pellet mills servicing the dairy, poultry layer and broiler, pig, sheep ruminant, beef ruminant, horse and aquaculture sectors. Ridley operates manufacturing sites across multiple Australian states under the Cottesloe (poultry feed), Ridley AgriProducts (general livestock feed) and Ridley Aqua-Feed (aquaculture feed) brands. Coprice (Riverina rice-based feed) is a major specialist livestock feed manufacturer with a strong presence in the rice-growing regions of the Riverina and a complementary horse feed and farm livestock feed portfolio. Riverina Stockfeeds services the southern New South Wales mixed-farming and dairy sector. Wagga Stockfeeds services the Wagga Wagga region. Lienert Australia specialises in the medicated premix and ionophore-class additive segment with APVMA-registered product for ruminant, poultry and pig nutrition.

What makes intensive livestock CAFO HVAC mechanically distinctive

Combustible grain and feed dust deflagration risk — the single highest acute hazard in the feed prep mill

Grain dust, cereal dust and animal feed dust from wheat, barley, sorghum, corn, soy, canola, lupin, faba bean and triticale are combustible particulate solids with Kst values typically in the 100 to 160 bar metres per second range — classified as a St 1 dust explosion class. Under AS/NZS 60079.10.2 (Explosive Atmospheres — Classification of Areas — Combustible Dust Atmospheres) and AS 3957 (Dust Hazard), the interior of the silo, pneumatic conveyor, bucket elevator, hammermill, pellet mill, dust collector, baghouse and cyclone is a Zone 21 hazardous area while the exterior space around the equipment is Zone 22. NFPA 660 (2025) is the global authoritative consolidated combustible particulate solids standard and supersedes the legacy NFPA 654, NFPA 61 (agricultural dust), NFPA 484 (metal dust) and NFPA 664 (wood dust) into one unified standard.

The duct system engineering response is heavy-gauge bonded and grounded carbon steel or galvanised duct with bolted flanged connections, electrically continuous across every flange via copper bonding strap, explosion isolation valves at every transition between equipment, NFPA 68 deflagration vent panels on dust collectors and baghouses sized for the Kst value of the dust species, and intrinsically safe instrumentation throughout. The minimum explosible concentration MEC for grain dust is approximately 50 to 60 grams per cubic metre; the minimum ignition energy MIE is approximately 10 to 30 millijoules — well within the energy of a static discharge from an ungrounded duct section or a friction spark from a pneumatic conveyor impeller. The JBS Beef City feed prep mill, the Mort & Co Grassdale ration mill, the SunPork piggery feed mill, the Inghams broiler feed delivery network, the Pace Farm egg layer feed system and the Ridley Corporation pellet mill all run this envelope with full NFPA 660 engineering controls.

Ammonia — THE controlling worker exposure parameter inside the piggery and poultry shed

Ammonia NH3 at 25 ppm 8-hour TWA and 35 ppm 15-minute STEL is THE controlling worker exposure parameter inside the SunPork piggery farrowing crate room, the SunPork grower-finisher shed, the Rivalea Corowa breeder unit, the Inghams broiler shed at 35-day grow-out, the Baiada Steggles broiler shed, the ProTen contract grower shed, the Cordina NSW broiler shed, the Hazeldenes VIC broiler shed, the Pace Farm egg layer barn, the Sunny Queen Australia egg layer barn, the Pirovic Egg Farms layer barn and the Farm Pride layer barn. Ammonia from urea decomposition in manure and litter is the dominant chronic exposure that drives the AS 4485 piggery and poultry shed tunnel ventilation design.

Chronic exposure to 25 to 50 ppm ammonia causes conjunctivitis, chronic bronchitis, reduced lung function, accelerated respiratory ageing and increased asthma prevalence in piggery and poultry workers. The bird and pig also lose productivity (reduced feed conversion ratio, reduced weight gain, increased mortality, increased footpad dermatitis in broilers, increased respiratory disease prevalence) when ambient NH3 exceeds 20 ppm inside the shed. The HVAC duct response is high-airflow tunnel ventilation at 8 to 12 metres per second longitudinal air velocity inside the shed, negative pressure 30 to 50 Pascals shed-to-ambient, cool cell pad evaporative cooling on the inlet (Munters CelDek or equivalent), variable-speed extract fans at the discharge end (typically 1.5 metre diameter belt-driven axial fans, 8 to 12 fans per shed depending on the bird stocking density, the ambient temperature and the shed length), and continuous NH3 monitoring at the bird height with alarm at 20 ppm and shutdown control feedback at 25 ppm. SBKJ supplies the tunnel inlet plenum and the discharge fan plenum ductwork in heavy-gauge galvanised with bolted flanged construction throughout the shed envelope.

Hydrogen sulfide H2S — the single highest acute fatality risk on any intensive livestock site

Hydrogen sulfide H2S at 10 ppm 8-hour TWA and 15 ppm 15-minute STEL is the single highest acute fatality risk on any Australian intensive livestock site. H2S is generated by anaerobic decomposition of sulfur-containing protein and amino acid in manure, slurry, lagoon water and anaerobic digester biogas. The SunPork piggery slurry pit, the Rivalea Corowa breeder unit slurry, the JBS Yardea cattle feedlot effluent lagoon, the Mort & Co Grassdale runoff dam, the Pace Farm caged layer manure scrape, the Sunny Queen Australia barn effluent, the Inghams broiler shed end-of-cycle litter clean-out, the Baiada Steggles end-of-cycle litter, and crucially the anaerobic digester biogas at the largest sites operating fixed-dome digesters or covered lagoon biogas capture all generate H2S above the WES threshold during specific operations.

H2S becomes acutely lethal at 200 to 300 ppm with no warning because olfactory paralysis sets in at concentrations above 100 ppm and the worker can no longer detect the gas by smell. Vault entry into manure pit, slurry pit, effluent sump or anaerobic digester is the highest acute fatality scenario in the Australian intensive livestock sector. Every operator must operate a Confined Space Entry permit-to-work programme per AS 2865 with continuous H2S, O2, CH4 and CO monitoring before entry, 30 air changes per hour mechanical ventilation, full body harness with retrieval line, standby attendant outside the space, and shutdown of any agitation or pump-out activity that releases dissolved H2S from the slurry. The HVAC duct response on a piggery slurry pit is dedicated 316L stainless extract from the pit headspace, sized for at least 30 air changes per hour at peak vapour load, discharging via 316L duct to a chemical scrubber and biofilter polish.

Methane CH4 and anaerobic digester biogas — AS/NZS 60079 Zone 0/1 hazardous area

Anaerobic digester biogas at the largest Australian piggery, cattle feedlot and poultry sites is approximately 55 to 65 percent methane CH4, 30 to 40 percent CO2, 1 to 3 percent H2S and trace water vapour, ammonia and mercaptan. Methane has a Lower Explosive Limit LEL of 5 percent in air by volume; under AS/NZS 60079.10.1 the interior of the digester vessel, the gas-tight piping run, the biogas storage holder (typically a double-membrane gas dome), the H2S scrubber vessel and the gas compressor skid are Zone 0 or Zone 1 hazardous areas. The space immediately surrounding any flanged joint, valve, instrument tapping, sample point or vent stack discharge is Zone 2. NFPA 853 (Standard for the Installation of Stationary Fuel Cell Power Systems and the parallel anaerobic digester biogas guidance) is the global authoritative reference.

Methane is also generated from enteric fermentation in cattle (rumen methane), from manure lagoon and covered effluent pond, and from feedlot pen surface in smaller quantities. Methane is the dominant Australian agriculture greenhouse gas contributor and a focus of the National Greenhouse and Energy Reporting NGER scheme; the carbon credit pathway for anaerobic digester capture and combustion is the dominant emission-reduction project type for the larger feedlot and piggery operators. The HVAC duct response on the biogas system is dedicated explosion-rated extract, intrinsically safe instrumentation throughout, continuous methane monitoring with alarm at 25 percent of LEL (1.25 percent CH4 in air) and shutdown at 50 percent of LEL, and electrically bonded and grounded ductwork.

Endotoxin, microbial bioaerosol and zoonotic disease — the under-appreciated chronic hazard

The Australian intensive livestock worker is chronically exposed to high concentrations of endotoxin (lipopolysaccharide LPS from Gram-negative bacteria cell walls), peptidoglycan (Gram-positive bacteria cell wall fragment), beta-glucan (fungal cell wall fragment), feather dander, hair, skin, feed particulate and urine droplet bioaerosol. The microbial flora includes Salmonella enterica (subspecies including Typhimurium, Enteritidis, Heidelberg, Infantis), Campylobacter jejuni and coli, pathogenic E. coli (including O157:H7), Brucella suis (piggery occupational zoonosis), Coxiella burnetii (Q-fever, primarily cattle and small ruminant occupational zoonosis), Mycobacterium avium subspecies paratuberculosis (Johne's disease in ruminant), Newcastle disease virus (poultry), HPAI Highly Pathogenic Avian Influenza H5N1 (poultry, with cross-species human pandemic risk), ASF African Swine Fever (piggery, with severe trade and biosecurity consequences), FMD Foot-and-Mouth Disease (cattle, pig, sheep, with catastrophic trade consequences), Hendra virus (horse with cross-species human risk), and Australian bat lyssavirus (bat with cross-species risk).

The HVAC duct response is HEPA-filtered supply where the AHA Animal Health Australia framework requires biosecurity isolation (mass mortality response, suspect HPAI or ASF outbreak), dedicated extract at every operator interface station with capture velocity 0.5 to 1.0 metres per second, positive pressurisation cascade in the hatchery and veterinary isolation envelope, negative pressurisation cascade in the mass mortality and rendering envelope, and AS/NZS 2243.3 PC2 biosafety reference for the on-farm veterinary diagnostic and sampling area. The ASHRAE 170 (Ventilation of Health Care Facilities) framework is referenced for the isolation room envelope at 12 air changes per hour total and 2 air changes per hour outdoor air with HEPA-filtered extract before discharge.

Fugitive odour emission — the dominant regulatory pathway under NSW EPA, VIC EPA, QLD DES

The Australian intensive livestock odour emission envelope is the single largest source of community complaint in any rural local government area and is the dominant regulatory pathway under the NSW EPA POEO (Protection of the Environment Operations Act 1997), the VIC EPA Environment Protection Act 2017 and the QLD DES Environmental Protection Act 1994. The dominant odour species are ammonia NH3, hydrogen sulfide H2S, volatile fatty acids VFAs (acetic, propionic, butyric, valeric, isovaleric), amines (trimethylamine, dimethylamine, putrescine, cadaverine), skatole and indole (tryptophan decomposition in piggery slurry), and mercaptans (methyl mercaptan, dimethyl sulfide).

The three-stage odour control train is the industry standard at the JBS Beef City rendering and effluent, the Mort & Co Grassdale composting envelope, the SunPork piggery slurry treatment, the Rivalea Corowa lagoon, the Inghams broiler shed end-of-cycle litter handling, the Baiada egg layer barn ventilation discharge, the Pace Farm composting and the Sunny Queen composting envelope. Stage one is the chemical wet scrubber (sodium hypochlorite for ammonia capture, or sulfuric acid for ammonia capture as ammonium sulfate fertilizer byproduct). Stage two is the activated carbon adsorber for smaller plants or the regenerative thermal oxidiser RTO at 800 degrees Celsius for high-load sites. Stage three is the biofilter polish with engineered wood chip, peat or compost media bed at minimum 30 to 45 second empty-bed contact time. The discharge stack is sized for 1.5 metres per second minimum exit velocity and 3 metres minimum above adjacent occupied buildings. SBKJ supplies the odour control ductwork in 316L stainless for the scrubber inlet and 309/310S high-temperature stainless for the RTO exhaust stack.

Cattle feedlot HVAC duct — feed prep, pen capture, abattoir and effluent

Feed prep mill at JBS Beef City, Mort & Co Grassdale and Smithfield

The feedlot feed prep mill is the dominant grain handling and pellet mill envelope inside any major Australian cattle feedlot. JBS Beef City near Toowoomba QLD processes 1,000 tonnes of ration per day across multiple mills supporting the 75,000+ head feedlot. Mort & Co Grassdale near Dalby QLD operates the largest single-site feedlot feed prep mill in Australia, supporting the 75,000+ head feedlot. The Smithfield Cattle Company NSW feedlot operates its own feed prep mill. Each site combines grain reception silos (Zone 21 hazardous area under AS/NZS 60079.10.2), bucket elevators and pneumatic conveyors (Zone 21 interior), hammermills and roller mills (Zone 22 exterior with aspirate at Zone 21 interior), mixer and ribbon-blender ration batching, steam flaker for the corn and barley grain processing, pellet mill conditioner and die where ration is pelleted, cooler discharge, and bulk feed truck loading bay for the in-yard distribution to the pen feed bunks.

The HVAC duct response at the JBS Beef City, Mort & Co Grassdale, Smithfield, Killara, Rangers Valley and Stanbroke feedlot feed prep mills is heavy-gauge galvanised carbon steel 1.5 to 2.0 millimetre with bolted flanged construction throughout the dust extraction system, electrically continuous, with explosion isolation valves at every equipment transition (silo to conveyor, conveyor to hammermill, hammermill to mixer, mixer to pellet mill, pellet mill to cooler), and NFPA 68 deflagration vent panels on every dust collector and baghouse. The cyclone separator on the secondary aspirate is dedicated 304L stainless. Continuous respirable and inhalable dust monitoring at the operator interface with action level at 75 percent of WES. SBKJ supplies the feed prep mill ductwork using the SBFB-1500 spiral fitting machine and the SBAL-V auto duct line in galvanised heavy-gauge variant.

Open feedlot pen — fugitive NH3, H2S, CH4 and odour capture

The open feedlot pen at JBS Yardea SA, JBS Caroona NSW, JBS Beef City QLD, Teys feedlots, Mort & Co Grassdale and Pinegrove, Smithfield, Killara, Rangers Valley and Stanbroke carries 18,000 to 90,000 head on the surface of the feedlot pad. The pen surface generates fugitive ammonia (urea decomposition in cattle urine), hydrogen sulfide (anaerobic decomposition in pen mud and runoff), methane (enteric fermentation from cattle, plus pen surface anaerobic decomposition) and a broader VFAs, amines and skatole odour fingerprint. The fugitive emission cannot be ducted in the traditional sense — the pen is an open exposure to ambient airshed — but the runoff dam, effluent pond and sediment trap downhill of the pen are the controlled emission points that can be ducted and treated.

The effluent management envelope is engineered to the ALFA Cattle Feedlot Code of Practice and the state EPA Air Quality consent. The runoff dam captures pen runoff after rainfall events; the effluent pond holds the runoff for evaporation and irrigation re-use; the sediment trap captures suspended solids before lagoon discharge. Each is a fugitive odour source and a fugitive methane and H2S source. The larger sites cover the effluent lagoon with an HDPE or LDPE cover sheet and capture the biogas for anaerobic digester combustion or atmospheric flaring — this converts a fugitive methane emission into a controlled emission and generates carbon credit revenue under the Emissions Reduction Fund ERF. The HVAC duct response on the covered lagoon biogas capture is dedicated 316L stainless skirt extract piping to the H2S scrubber and the biogas combustion engine or flare stack.

Cattle abattoir cross-over — ASHRAE 170 ventilation cascade

The cattle abattoir at JBS Beef City (3,400 head per day), the Teys Beenleigh and Wagga Wagga abattoirs, the Stanbroke abattoir, the Mort & Co Grassdale Beef Australia abattoir and the Smithfield Cattle Company processing all operate the post-slaughter cross-over from live animal to chilled carcase. The cross-over sequence is: lairage and holding pen (live animal in ambient pen ventilation); race and stunning box (captive bolt stunning, AS 4696 food premises and AS 5750 humane slaughter compliance); sticking and bleed (carcase discharge into the bleed-out trough); scalding tank (hot water bath for hide removal preparation at 60 degrees Celsius for pigs only, not applied to cattle); dehiding station (hide pulled mechanically); evisceration (gut, offal and viscera removal into the dedicated rendering and inedible byproduct stream); splitting (carcase split into sides); chilling (chiller floor with ammonia refrigeration, chilling carcase to 4 degrees Celsius internal); boning room (carcase broken into primal cuts at 4 to 10 degrees Celsius); packing and dispatch.

Each cross-over zone has a different ASHRAE 170 ventilation pressurisation cascade. The lairage and live animal area is at neutral ambient pressure. The stunning box is at slight positive pressure (plus 5 Pa) for operator comfort. The sticking and bleed area is at negative pressure (minus 5 Pa) to capture aerosolised blood and aerosol containment. The evisceration area is at negative pressure (minus 10 Pa) to capture viscera odour and aerosol. The chilling and boning area is at positive pressure (plus 10 Pa) and conditioned to 4 to 10 degrees Celsius with R-717 ammonia refrigeration. The HVAC duct material is 316L stainless throughout the wet processing zone (sticking, evisceration, scalding, chilling and boning) because of the saturated chloride exposure from the chlorinated water sanitation and the daily wash-down. AQIS export certification requires full traceability through every cross-over zone and the FSANZ 4.2.1 to 4.2.4 (Standards 4.2.1, 4.2.2, 4.2.3, 4.2.4 covering meat and meat product, primary processing standard, slaughter and dressing of game animals and Bivalve mollusc primary production standard) is the binding food safety reference.

Piggery HVAC duct — SunPork, Rivalea, Linley Valley Pork, AS 4485

Farrowing room and weaner room — climate-controlled at 28 to 30 and 26 to 28 degrees Celsius

The piggery farrowing room at the SunPork Caboolture hub, the SunPork Berrimah NT site, the SunPork Hopetoun VIC site, the SunPork Yongala SA site and the Rivalea Corowa NSW breeder unit is the highest climate-control specification room in the Australian piggery sector. Operating at 28 to 30 degrees Celsius for the suckling piglet thermal comfort and at 50 to 70 percent RH, the room is the tightest temperature tolerance envelope in the AS 4485 piggery design framework. The sow at higher body mass produces high metabolic heat load; the piglet at lower body mass requires elevated ambient temperature for thermoregulation. The conflict between sow and piglet thermal requirement is resolved by localised piglet thermal microenvironment (heat lamp, heat mat or hover) at 32 to 35 degrees Celsius for the piglet while the room ambient is held at 22 to 24 degrees for the sow.

The farrowing room HVAC envelope is conditioned with HEPA-filtered supply (MERV 13 minimum), localised supply diffusers above each farrowing crate, dedicated extract at the slurry channel below the crate (the slurry channel is the dominant ammonia and H2S source in the farrowing room), and continuous NH3 and H2S monitoring at the sow height with alarm at 20 ppm NH3 and 5 ppm H2S. The weaner room at 26 to 28 degrees Celsius follows the same envelope with reduced thermal load and elevated ammonia load from the post-weaning gut transition manure chemistry. SBKJ supplies the farrowing room and weaner room ductwork in 304L stainless with continuous welded longitudinal seams via the SBAL-V auto duct line and the SBLR-600 longitudinal seam welder.

Grower-finisher and breeder shed — tunnel ventilation at 22 to 18 and 18 to 22 degrees Celsius

The piggery grower-finisher shed at the SunPork Caboolture network, the Rivalea Corowa grower-finisher unit, the SunPork Hopetoun VIC site and the SunPork Yongala SA site is the dominant air-volume piggery envelope. Operating at 22 to 18 degrees Celsius depending on pig age (grower at 22 to 20, finisher at 20 to 18) and at 50 to 70 percent RH, the shed runs tunnel ventilation at 8 to 12 metres per second longitudinal air velocity, 30 to 50 Pa negative pressure shed-to-ambient, cool cell pad evaporative cooling on the inlet (Munters CelDek), variable-speed extract fans at the discharge end (typically 1.5 metre diameter belt-driven axial fans, 6 to 10 fans per shed), and continuous NH3 and H2S monitoring at pig height with alarm at 20 ppm NH3 and 5 ppm H2S.

The breeder shed at 18 to 22 degrees Celsius follows the AS 4485 envelope with additional consideration for the AI artificial insemination room and the boar handling area. The boar urine and semen handling area requires dedicated extract with capture velocity 0.5 to 1.0 metres per second at the operator interface to manage operator exposure to the strong boar pheromone (5-alpha-androstenone). The HVAC duct material is heavy-gauge galvanised in the dry tunnel inlet and discharge plenum, with 304L stainless in the wet slurry pit headspace extract and the wash-down area extract. SBKJ supplies the piggery shed ductwork using the SBAL-V auto duct line in galvanised heavy-gauge for the tunnel and the SBAL-V in 304L stainless variant for the wet processing zones.

Slurry pit and effluent lagoon — the H2S and NH3 source

The piggery slurry pit beneath the grower-finisher shed at the SunPork Caboolture, the SunPork Berrimah, the SunPork Hopetoun, the SunPork Yongala and the Rivalea Corowa network is the dominant H2S source on any Australian piggery site. The slurry pit is typically a deep concrete pit beneath the slatted floor of the grower-finisher pen, collecting urine and faeces from the pigs above and accumulating anaerobic decomposition for the slurry pump-out cycle (typically weekly to fortnightly to a holding tank or directly to an anaerobic digester or land-application irrigation envelope).

The slurry pit headspace generates H2S at concentrations above 100 ppm during agitation or pump-out activity — the agitation releases dissolved H2S from the slurry into the headspace and into the pen above. Confined Space Entry into the slurry pit is one of the highest acute fatality scenarios in Australian agriculture. The HVAC duct response is dedicated 316L stainless extract from the pit headspace, sized for at least 30 air changes per hour at peak vapour load, discharging via 316L duct to a chemical wet scrubber and biofilter polish. The continuous H2S monitoring at the pen floor above the slurry pit triggers automatic increase in tunnel ventilation airflow when H2S exceeds 5 ppm at pig height. Larger Australian piggery sites use deep-pit storage with extended residence time and integrated anaerobic digester biogas capture — this converts the H2S and methane emission into controlled emission and generates renewable energy revenue.

Poultry broiler shed HVAC duct — Inghams, Baiada, ProTen, Cordina, Hazeldenes, AS 4485

Chick brooder envelope at 32 to 34 degrees Celsius

The chick brooder at the Inghams broiler grow-out shed network, the Baiada Steggles network, the ProTen contract grower network, the Cordina NSW broiler shed, the Hazeldenes VIC broiler shed and the Bartter Steggles network operates at 32 to 34 degrees Celsius for the day-old chick thermal comfort. The brooder envelope spans the first 7 to 10 days of the grow-out cycle. Operating at 32 to 34 degrees ambient at the chick height with 50 to 70 percent RH, the brooder requires localised heat source (typically radiant gas brooder or hot air furnace) and tight humidity control to manage chick respiratory disease prevalence.

The brooder HVAC envelope is conditioned with reduced tunnel ventilation airflow (minimum ventilation rate of 1.0 cubic metre per minute per 1000 birds, ramping up as the chick grows and the ambient temperature set-point reduces), HEPA-filtered supply where the hatchery biosecurity cascade requires (post-hatch chicks are AHA Animal Health Australia framework risk for Salmonella, Pullorum, Marek's disease and HPAI biosecurity exposure), and continuous CO and CO2 monitoring (the gas brooder generates CO and CO2 emission — the WES for CO is 30 ppm STEL, for CO2 is 5,000 ppm 8-hour TWA, both monitored continuously). The HVAC duct material is heavy-gauge galvanised with bolted flanged construction throughout, transitioning to 304L stainless at the wet litter clean-out and the daily wash-down area.

Grow-out envelope at 18 to 24 degrees Celsius — tunnel ventilation at 8 to 12 m/s

The broiler grow-out shed at Inghams, Baiada, ProTen, Cordina and Hazeldenes is the largest single-species intensive livestock envelope by air volume in Australia. A typical Inghams broiler shed is 150 metres long by 18 metres wide by 3 metres tall — an internal volume of approximately 8,100 cubic metres — carrying 40,000 to 60,000 birds per cycle with stocking density at the AS 4485 and ACMF Chicken Welfare Code maximum 34 to 40 kg per square metre live weight at finish. Operating at 18 to 24 degrees Celsius depending on bird age and at 50 to 70 percent RH, the shed runs tunnel ventilation at 8 to 12 metres per second longitudinal air velocity, 30 to 50 Pa negative pressure shed-to-ambient, cool cell pad evaporative cooling on the inlet (Munters CelDek or equivalent), and variable-speed extract fans at the discharge end (typically 1.5 metre diameter belt-driven axial fans, 8 to 12 fans per shed).

The Ross 308 and Cobb 500 broiler genetics dominate the Australian broiler grow-out at Inghams, Baiada and ProTen with 38 to 45 day grow-out cycle and target live weight of 2.0 to 2.5 kg. The bird metabolic heat load is high — a fully-grown broiler at 2.0 kg generates approximately 12 watts sensible heat plus 4 watts latent heat — meaning a 50,000-bird shed at finish carries a sensible heat load of approximately 600 kW and a latent load of 200 kW, dominating the tunnel ventilation cooling design. The ammonia, hydrogen sulfide and CO2 loadings ramp up across the grow-out cycle with the bird metabolic and excretion output. Continuous NH3 monitoring at bird height with alarm at 20 ppm; continuous H2S monitoring with alarm at 5 ppm; continuous CO2 monitoring with alarm at 5,000 ppm. SBKJ supplies the broiler shed tunnel ventilation inlet plenum and discharge fan plenum ductwork in heavy-gauge galvanised with bolted flanged construction via the SBAL-V auto duct line and the SBAL-III mid-range auto duct line.

End-of-cycle litter clean-out — the dominant odour and dust event

The end-of-cycle litter clean-out at the Inghams, Baiada, ProTen, Cordina and Hazeldenes broiler shed network is the single largest fugitive odour and dust event in the grow-out cycle. After bird despatch to the processing plant, the spent litter (a mix of pine wood shavings, manure, urine residual, feather and skin dander) is mechanically scraped, windrowed and removed from the shed for composting, mushroom substrate sale or land-application as fertiliser. The litter clean-out event releases concentrated ammonia, hydrogen sulfide, endotoxin bioaerosol and respirable dust at concentrations significantly above the WES inside the shed during the operation.

Worker PPE during clean-out is P2 respirator minimum (P3 for the Inghams sites with elevated endotoxin loading), coveralls and eye protection. The HVAC duct response is increased tunnel ventilation airflow during the operation (typically 1.5x normal grow-out airflow) and dedicated capture hood on the litter discharge conveyor to the truck loading bay. The composting envelope downstream of the litter clean-out runs the three-stage odour control train described above with biofilter polish before atmosphere release.

Egg layer barn HVAC duct — Pace Farm, Sunny Queen, Pirovic, Farm Pride, AS 5807

Free range envelope under AS 5807 Free Range Egg Standards 2017

The Australian egg layer sector under the Free Range Egg Standards 2017 (codified into AS 5807) operates with a maximum 10,000 birds per hectare for the outdoor stocking density of any product labelled "free range" and requires information disclosure on outdoor stocking density on the egg carton labelling. The Pace Farm Beechwood NSW free range site, the Pace Farm Berkshire Park NSW site, the Sunny Queen Australia free range network across QLD, the Pirovic Egg Farms NSW free range capacity and the Farm Pride VIC free range capacity all run AS 5807 compliant systems.

The free range layer barn envelope combines indoor barn housing (litter floor, perches, nest boxes, drinker and feeder lines) with outdoor range access via pop-hole doors during daylight hours. The indoor barn HVAC envelope is conditioned with tunnel ventilation at 8 to 12 metres per second when ambient warrants, with cool cell pad evaporative cooling on the inlet, variable-speed extract fans at the discharge end, and natural ventilation backup via curtain side-wall during mild conditions. Operating at 16 to 22 degrees Celsius for the adult laying hen with 50 to 70 percent RH. Continuous NH3 monitoring at bird height with alarm at 20 ppm. The dominant ammonia source is the litter floor where manure accumulates between weekly or fortnightly clean-out cycles. SBKJ supplies the free range barn ductwork in heavy-gauge galvanised with bolted flanged construction throughout.

Caged colony envelope — Sunny Queen, Pace Farm

The caged colony envelope at the Sunny Queen Australia caged sites, the Pace Farm caged sites and the Pirovic Egg Farms caged sites operates with multi-tier cage systems (typically 4 to 8 tiers) carrying 60 to 100 birds per cage in colony cages compliant with the Australian Code of Practice for the Welfare of Animals. The manure scrape conveyor under each tier collects the manure to a centralised slurry channel and removes from the barn typically daily or twice-daily. The manure scrape envelope is the dominant ammonia and H2S source — concentrated manure at high moisture content rapidly generates ammonia via urea decomposition and hydrogen sulfide via anaerobic decomposition at the sub-floor scrape conveyor and the slurry channel discharge.

The HVAC envelope is conditioned with tunnel ventilation at the higher airflow rate appropriate to the high bird stocking density (the caged colony carries approximately 10 to 12 birds per square metre floor area equivalent across all tiers, versus the free range and barn at 7 to 9 birds per square metre). Dedicated extract at the manure scrape conveyor and the slurry channel discharge with capture velocity 1.0 to 1.5 metres per second to manage ammonia at the operator interface during clean-out and inspection. The HVAC duct material is 304L stainless in the wet manure scrape and slurry channel zones and heavy-gauge galvanised in the dry barn ventilation envelope.

Egg packing room — the cleanroom-adjacent envelope

The egg packing room at the Pace Farm Beechwood, Pace Farm Berkshire Park, Sunny Queen, Pirovic and Farm Pride sites operates as a cleanroom-adjacent envelope under AS 4696 food premises and the FSANZ 4.2.5 (Standard 4.2.5 Primary Production and Processing Standard for Eggs and Egg Product) reference. Operating at 18 to 22 degrees Celsius with HEPA-filtered supply at MERV 13 minimum and positive pressurisation at plus 15 Pa to maintain ingress prevention from the layer barn into the packing envelope. The egg washing, grading, candling, weighing and packing line operates under continuous online vision inspection with Salmonella biosecurity controls throughout (Pullorum disease and Salmonella enterica subspecies Typhimurium and Enteritidis are the dominant egg biosecurity concerns under the AHA Animal Health Australia framework and FSANZ 4.2.5).

Hatchery HVAC duct — Inghams, Baiada, Pace Farm hatchery network

The poultry hatchery is the most biosecurity-sensitive envelope in the Australian poultry sector. The Inghams hatcheries at Bringelly NSW, Pakenham VIC and Wanneroo WA, the Baiada Steggles hatchery network, the Pace Farm pullet rearing hatchery, the Sunny Queen Australia hatchery network and the ProTen breeder farm hatcheries all operate as cleanroom-adjacent envelopes with HEPA-filtered supply at H13 or H14 grade, terminal HEPA at the incubator and hatcher cabinet, positive pressurisation cascade from the hatcher and setter room outward to the corridor and ante-room, and dedicated extract at every operator interface station with capture velocity 0.5 to 1.0 metres per second.

The setter incubator (18 days at 37.5 degrees Celsius and 55 to 60 percent RH) and the hatcher (3 days at 37.0 degrees Celsius and 65 to 70 percent RH) are the controlled-temperature and controlled-humidity envelopes. NatureForm, Petersime and Pas Reform are the dominant incubator equipment suppliers. The chick sexing and vaccination station (in-ovo Marek's disease vaccination injected into the egg at day 18 of incubation, post-hatch coccidiosis spray vaccination, post-hatch Newcastle disease vaccination) requires dedicated extract at the operator face with capture velocity 1.0 metres per second to manage vaccine aerosol and Marek's disease vaccine vector exposure.

The egg breakage and sanitation waste stream from broken egg, infertile egg and dead-in-shell embryo is the dominant biosecurity risk in the hatchery — AHA Animal Health Australia framework requires the waste stream to be rendered or incinerated under biosecure conditions, never permitted to atmosphere release or composting in an open environment. The HVAC duct response is dedicated 316L stainless extract from the waste handling area, discharging via 316L duct to a HEPA-filtered exhaust before atmosphere release. The AS/NZS 2243.3 PC2 biosafety reference is invoked for the on-farm veterinary diagnostic and sampling area in the hatchery, including the day-old chick blood and tissue sampling for Salmonella, Pullorum and Mycoplasma gallisepticum surveillance.

Animal feed mill HVAC duct — Ridley, Coprice, Riverina Stockfeeds, Lienert premix

The animal feed mill envelope at the Ridley Corporation ASX:RIC integrated mill network, the Coprice Riverina rice-based feed mill, the Riverina Stockfeeds southern New South Wales mills, the Wagga Stockfeeds Wagga Wagga mill and the Lienert Australia premix manufacturing site is a textbook Zone 22 dust hazardous area under AS/NZS 60079.10.2 with NFPA 660 combustible particulate solids engineering throughout. The cereal grain dust, vegetable meal dust, animal feed dust and pellet fines have Kst values in the 100 to 160 bar metres per second range; the deflagration vent panel sizing on the dust collector, baghouse and cyclone follows NFPA 68 calculations.

APVMA-registered medicated premix (ionophore-class antibiotic for ruminant including monensin and lasalocid, anti-coccidial for poultry, anthelmintic for sheep and beef) is added at the mixer station and triggers tighter operator exposure control under SafeWork Australia chemical handling guidance. The medicated premix dispensing station operates as a dedicated dust extraction envelope with HEPA-filtered extract before atmosphere release, dedicated PPE for the operator (P2 respirator minimum) and locked storage for the premix product.

The HVAC duct material is heavy-gauge galvanised throughout the dust extraction system serving the silo, conveyor, hammermill, mixer, pellet mill conditioner, pellet mill die and cooler with bolted flanged construction, electrically bonded and grounded at every flange, with explosion isolation valves at every equipment transition. The Ridley Corporation pellet mill at Cottesloe (poultry), the Coprice Riverina ruminant feed mill, the Lienert Australia premix manufacturing site and the Riverina Stockfeeds mills all run equivalent envelopes. SBKJ supplies the livestock feed pellet mill ductwork using the SBFB-1500 spiral fitting machine and the SBAL-V auto duct line in heavy-gauge galvanised variant. The SBPC1500 plasma cutter in spark-resistant configuration prepares plate for the dust collector housing and the cyclone separator.

Manure handling, effluent lagoon and anaerobic digester biogas — AS/NZS 60079 Zone 1 NFPA 853

Manure scrape and slurry handling

The manure scrape envelope at the egg layer caged colony (Pace Farm, Sunny Queen, Pirovic, Farm Pride), the piggery slurry pit (SunPork, Rivalea, Linley Valley) and the cattle feedlot manure pad (JBS, Teys, Stanbroke, Mort & Co, Smithfield, Killara, Rangers Valley) is the upstream collection point for the downstream anaerobic digester, lagoon, composting and land-application treatment train. The manure scrape conveyor under the caged layer tier, the slatted floor slurry pit under the piggery grower-finisher pen, and the manure pad scrape under the feedlot pen all collect concentrated manure at high moisture content (typically 75 to 90 percent water) into the centralised slurry channel or lagoon influent line.

The manure scrape generates ammonia (urea decomposition), hydrogen sulfide (anaerobic decomposition), methane (anaerobic decomposition), volatile fatty acids and amine odour at concentrations significantly above the WES at the conveyor and discharge point. Dedicated extract at the manure scrape conveyor and the slurry channel discharge with capture velocity 1.0 to 1.5 metres per second is the standard installed configuration. The HVAC duct material is 316L stainless because of the aggressive ammonia and chloride exposure. SBKJ supplies the manure scrape and slurry channel ductwork using the SBAL-V auto duct line in 316L stainless variant with the SBLR-600 longitudinal seam welder for continuous TIG seam construction.

Effluent lagoon and covered lagoon biogas capture

The effluent lagoon at the JBS feedlot network, the Mort & Co Grassdale, the Smithfield Cattle Company, the Killara Quirindi, the Rangers Valley feedlot, the SunPork piggery network and the Rivalea Corowa is the dominant fugitive emission source on any intensive livestock site and the dominant odour emission source in any rural local government area surrounding the operation. The lagoon holds the manure-laden runoff and slurry for anaerobic decomposition and evaporation, with the larger sites implementing covered lagoon biogas capture to convert the methane fugitive emission into controlled emission.

The covered lagoon biogas capture envelope uses an HDPE or LDPE membrane cover sheet floated on the lagoon surface, anchored to a perimeter trench, with a centralised gas collection skirt extracting the biogas through a 316L stainless piping run to the H2S scrubber, gas conditioning and combustion engine or atmospheric flare. The biogas typically contains 55 to 65 percent methane, 30 to 40 percent CO2, 1 to 3 percent H2S and trace water vapour and ammonia. The biogas piping is engineered to AS/NZS 60079.10.1 Zone 0/1 hazardous area; the H2S scrubber housing is engineered to AS/NZS 60079.10.1 Zone 1; the combustion engine genset skid is engineered to Zone 2. SBKJ supplies the covered lagoon biogas piping using the SBAL-V auto duct line in 316L stainless 1.5 mm variant with continuous welded longitudinal seam via the SBLR-600.

Anaerobic digester biogas — NFPA 853 and AS/NZS 60079 Zone 0/1

The largest Australian intensive livestock sites operate engineered anaerobic digester biogas systems for renewable energy generation and carbon credit revenue under the Emissions Reduction Fund ERF. The fixed-dome anaerobic digester at the SunPork piggery hubs, the engineered concrete digester at the larger Inghams broiler operations, the covered lagoon digester at the JBS feedlot network and the engineered tank digester at the Pace Farm composting and biogas operations all operate as Zone 0/1 hazardous areas with NFPA 853 reference framework.

The digester vessel interior, the biogas storage holder, the H2S scrubber vessel and the gas compressor skid are Zone 0 or Zone 1. The space immediately surrounding any flanged joint, valve, instrument tapping, sample point or vent stack discharge is Zone 2. Continuous methane monitoring with alarm at 25 percent LEL (1.25 percent CH4 in air) and shutdown at 50 percent LEL. Continuous H2S monitoring with alarm at 5 ppm and shutdown at 10 ppm. Continuous O2 monitoring on the digester headspace to confirm anaerobic environment is maintained. The biogas combustion engine (typically a converted natural gas engine or a dedicated biogas engine such as Jenbacher or Caterpillar G3500) generates 1 to 3 MW electrical output at the larger sites and provides on-site renewable electricity plus heat recovery for the digester and shed heating loads.

Odour control biofilter, chemical scrubber and RTO — the three-stage train

Stage one — chemical wet scrubber

The stage one wet scrubber on the feedlot pen capture, the piggery shed end exhaust, the broiler shed end-of-cycle litter capture, the egg layer barn extract and the rendering plant cooker discharge is typically a packed-bed counter-current scrubber with sodium hypochlorite (NaOCl) at 5 to 10 percent active chlorine concentration for combined ammonia and H2S capture, or sulfuric acid (H2SO4) at pH 2 to 3 for dedicated ammonia capture as ammonium sulfate fertiliser byproduct. The scrubber is sized for the peak vapour load with 25 percent safety margin. The scrubber housing is 316L stainless or FRP (fibre-reinforced plastic) construction.

Stage two — activated carbon adsorber or regenerative thermal oxidiser RTO

The stage two odour control is either an activated carbon adsorber (for smaller sites with moderate odour load) or a regenerative thermal oxidiser RTO (for larger sites with continuous high odour load and rendering attached). The RTO operates at 800 to 900 degrees Celsius combustion temperature with three-vessel switching for thermal efficiency (typically 90 to 95 percent thermal energy recovery). The RTO inlet, outlet and exhaust stack are engineered in 309/310S high-temperature stainless steel.

Stage three — biofilter polish

The stage three biofilter polish handles the residual odour after the wet scrubber and the adsorber or RTO. The biofilter is an engineered media bed (compost, peat or proprietary engineered media including wood chip, bark and inert support) with minimum 30 to 45 second empty-bed contact time. The biofilter operates at ambient temperature with humidified air to maintain biological activity in the media. Discharge from the biofilter is essentially odour-neutral and is released to atmosphere via a low-velocity dispersal stack.

Veterinary, artificial insemination and embryo transfer envelope

The veterinary and reproductive technology envelope on the larger Australian intensive livestock sites covers artificial insemination (AI), embryo transfer (ET), semen handling, semen liquid nitrogen cryostorage at minus 196 degrees Celsius, embryo cryostorage and pregnancy diagnosis ultrasound. The Australian Veterinary Association AVA professional standards, the APVMA chemical registration for the AI catheter lubricant and the embryo culture media, and the NHMRC National Health and Medical Research Council guidelines on veterinary research practice all apply.

The AI room at the SunPork breeder hub, the Rivalea Corowa breeder, the Inghams hatchery, the Baiada Steggles hatchery, the Pace Farm pullet rearing facility and the larger feedlot bull stations operate with HEPA-filtered supply, dedicated extract at the semen handling bench with capture velocity 1.0 metres per second, and a dedicated liquid nitrogen storage room with continuous O2 monitoring (the O2 displacement risk from liquid nitrogen evaporation in an enclosed space is the dominant acute fatality risk in any AI or ET facility — the WES for O2 is a minimum 19.5 percent volume in air, monitored continuously). The HVAC duct material is 316L stainless throughout because of the chloride exposure from sanitation chemistry and the cryogenic exposure at the liquid nitrogen vapour discharge.

Animal transport, truck wash and biosecurity envelope

The animal transport and truck wash envelope at every Australian intensive livestock site under AS 4485 and the AQIS biosecurity framework is the upstream and downstream biosecurity boundary of the operation. B-Double cattle truck and road train cattle transport between the feedlot, the abattoir and the rearing property; piggery truck transport between the breeder hub, the grower-finisher hub and the abattoir; broiler truck transport between the grow-out shed and the processing plant; and egg layer pullet transport between the rearing facility and the layer barn all run on dedicated livestock transport vehicles that must be washed and sanitised between every load to manage the biosecurity risk envelope.

The truck wash facility operates with hot water at 80 to 90 degrees Celsius, chlorine sanitation chemistry (sodium hypochlorite at 50 to 200 ppm free chlorine), peracetic acid or quaternary ammonium compound disinfectant, and high-pressure pump (typically 200 to 400 bar discharge pressure) with capture and treatment of the wash water and runoff. The HVAC envelope around the truck wash facility is conditioned with positive pressure to maintain operator comfort and prevent aerosol egress to the surrounding biosecurity envelope. Continuous monitoring of chlorine, peracetic acid and ammonia residual at the operator face. The HVAC duct material is 316L stainless because of the aggressive chloride and peracetic acid exposure.

Mortality management and mass mortality response — HPAI, ASF, FMD

The mortality management envelope at every Australian intensive livestock site under the AHA Animal Health Australia framework and the Biosecurity Act 2015 covers the routine daily mortality disposal (typically 1 to 5 percent of stocking per cycle for broilers, 0.5 to 2 percent for piggery, 0.1 to 1 percent for cattle feedlot) and the mass mortality response envelope for disease outbreak (HPAI H5N1 bird flu, ASF African Swine Fever, FMD Foot-and-Mouth Disease, Newcastle disease, lumpy skin disease, anthrax). The routine daily mortality is disposed via the on-site composting envelope, the rendering envelope at the Australian Renderers Association ARA member sites, or the on-site incineration where AHA Animal Health Australia framework permits.

The mass mortality response envelope is the highest biosecurity classification on the Australian intensive livestock site and is engineered to the ASHRAE 170 negative pressure isolation envelope with HEPA-filtered extract before discharge. Mass HPAI H5N1 depopulation at a poultry farm requires the entire shed to be sealed and the bird depopulation conducted under controlled atmosphere (typically CO2 gassing or whole-shed ventilation shutdown with elevated CO2). The carcase disposal is by on-site composting, deep burial, on-site rendering or off-site disposal to a licensed AHA Animal Health Australia-approved facility. The HEPA-filtered extract on the depopulation envelope manages the virus aerosol risk to the surrounding rural community. The HVAC duct material is 316L stainless with continuous welded longitudinal seams via the SBAL-V auto duct line and the SBLR-600 longitudinal seam welder.

Post-slaughter cold chain — ammonia refrigeration at JBS, Teys, SunPork, Inghams

The post-slaughter cold chain at JBS Beef City, Teys Beenleigh, Stanbroke, Mort & Co Grassdale Beef Australia, Smithfield, SunPork Caboolture pork processing, Rivalea Corowa pork processing, Linley Valley Pork WA processing, Inghams broiler processing, Baiada Steggles processing, Cordina processing NSW and Hazeldenes processing VIC runs R-717 ammonia refrigeration at industrial scale under AS/NZS 1677 and AS/NZS 5149. The IQF freezer at minus 25 to minus 35 degrees Celsius runs R-717 direct expansion or pumped circulation; the chiller floor at 4 to 10 degrees Celsius runs R-717 secondary loop or direct expansion. The compressor room is a Class I Zone 2 hazardous area under AS/NZS 60079.10.1 and is engineered to AS/NZS 1677 emergency ventilation requirements at 30 air changes per hour minimum.

The HVAC duct response is dedicated 316L stainless extract from the compressor room to a wet scrubber discharge, spark-resistant motor and damper actuator construction throughout the plant room, continuous ammonia monitoring with low-level alarm at 15 ppm and high-level shutdown at 25 ppm, and absolute prohibition of galvanised duct in any space where wet ammonia is possible. Modern lower-charge installations also use R-32, R-454B or R-744 CO2 transcritical for the smaller post-slaughter cold store applications — particularly in the further processing envelope at the Inghams marinade and cooked product line and the JBS portioning room. SBKJ supplies the ammonia plant ductwork using the SBAL-V auto duct line in 316L stainless variant with the SBPC1500 plasma cutter in spark-resistant configuration.

Further processing — deboning, portioning, marinade, cooked, IQF cold chain

The further processing envelope at the Inghams cooked and further processed product line, the JBS Australia portioning and marinade line, the Teys further processing, the SunPork further processing and the Baiada Steggles further processing operates as a separate AS 4696 food premises envelope downstream of the primary processing chiller. The deboning and portioning room at 4 to 10 degrees Celsius with R-717 ammonia secondary loop refrigeration; the marinade injection room with brine and seasoning solution at 4 degrees Celsius; the cooked product line with steam-cook oven (NFPA 86 industrial oven envelope) and chilled holding; the IQF freezer at minus 25 to minus 35 degrees Celsius; the MAP modified atmosphere packaging and vacuum pack line; the secondary packaging and case-pack line.

The HVAC duct envelope is 316L stainless throughout the wet processing zone because of the chloride exposure from the daily sanitation, the brine injection chemistry and the steam-cook condensate. The cooked product line steam-cook oven is engineered to NFPA 86 industrial oven Class B with combustion safety controls, purge cycle and overtemperature shutdown. The IQF freezer plenum and the cold store envelope are dedicated 316L stainless with vapour barrier continuity throughout to prevent condensation and ice formation on the insulation envelope.

SBKJ machine package for the Australian intensive livestock CAFO scope

SBKJ Group manufactures and supplies the complete HVAC duct fabrication machinery package for the Australian intensive livestock CAFO HVAC envelope. The SBAL-V auto duct line is the dominant machine for the high-volume tunnel ventilation inlet plenum, the tunnel discharge fan plenum, the feed prep mill dust extraction, the piggery and poultry shed envelope, the egg layer barn envelope, the manure handling and slurry pit extract, the anaerobic digester biogas piping, the odour control scrubber inlet and the post-slaughter cold chain ammonia plant room duct. The SBAL-V runs in galvanised heavy-gauge variant for the dry HVAC supply scope and in 304L or 316L stainless variant for the wet processing and corrosive exposure scope. The SBAL-III mid-range auto duct line supports the high-throughput tunnel inlet plenum production at the larger Inghams and Baiada broiler shed installation programmes.

The SBSF-1525 round flanger supports the heavy-gauge 250 degree Celsius / 2-hour fire-rated rendering and biogas ductwork and the AS 1530.4 fire-rated penetration scope. The SB-ZF1500 stitchwelder provides continuous TIG seam construction on the 316L stainless wet processing and biosecurity isolation duct scope. The SBFB-1500 spiral fitting machine provides the round-spiral duct fabrication for the grain dust, feed dust, litter and bedding dust conveying scope under NFPA 660. The SBPC1500 plasma cutter in spark-resistant configuration provides plate prep for the AS/NZS 60079 Zone 1 biogas, Zone 21/22 grain dust and Class I Zone 2 ammonia plant scope — the spark-resistant configuration keeps plate fabrication inside the hazardous area envelope without elevated ignition risk. The SBLR-600 longitudinal seam welder provides continuous TIG seam construction on the 316L stainless wet processing duct scope. The SBTF-1500, SBTF-1602 and SBTF-2020 spiral tubeformers provide the heavy-gauge spiral duct fabrication across the full diameter range from 100 to 2020 mm.

Standards consolidation and audit pathway

The Australian intensive livestock CAFO HVAC duct guide consolidates the multiple Australian Standards, NFPA references, industry codes and regulatory frameworks that govern the sector. AS 1668.2 (Mechanical Ventilation) and AS 4254 (Ductwork for Air-Handling Systems in Buildings) are the foundational ductwork references. AS 1530.4 (Fire Resistance Test) covers the fire-rated duct scope where the building separation requires a 1, 2 or 4 hour fire rating. AS/NZS 60079 (Explosive Atmospheres) covers the hazardous area classification for grain dust (Zone 21/22), biogas methane (Zone 0/1), ammonia plant (Class I Zone 2), LPG forklift and burner (Class I Zone 2) and feed silo grain dust (Zone 21/22). AS 3957 (Dust Hazard) covers the combustible particulate solids hazard classification.

NFPA 660 (2025) is the global authoritative consolidated combustible particulate solids standard. NFPA 68 (Standard on Explosion Protection by Deflagration Venting) and NFPA 69 (Standard on Explosion Prevention Systems) cover the deflagration vent and explosion prevention engineering. NFPA 853 (Standard for the Installation of Stationary Fuel Cell Power Systems and the parallel anaerobic digester biogas guidance) covers the biogas engineering. AS 4485 (Design and Operation of Australian Piggery and Poultry Buildings) is the binding shed design reference. AS 5807 (Free Range Egg Standards) codifies the Free Range Egg Standards 2017 maximum 10,000 birds per hectare. The ALFA Cattle Feedlot Code of Practice, the APL Pig Welfare Code, the ACMF Chicken Welfare Code, the Biosecurity Act 2015, the AHA Animal Health Australia framework, the APVMA Chemical Registration, the AQIS Export Certification and the RSPCA welfare envelope all apply concurrently.

The audit pathway runs through the ALFA NFAS accreditation audit for the cattle feedlot, the APL APIQ Plus audit for the piggery, the ACMF audit for the broiler and layer farm, the AS 5807 free range certification audit for the layer farm, the AHA Animal Health Australia surveillance and response inspection, the APVMA chemical registration dossier review, the AQIS export inspection for the abattoir and processing line, the PrimeSafe (Victoria), Safe Food Production Queensland and NSW Food Authority audits for the further processing scope, and the state EPA (NSW EPA, VIC EPA, QLD DES) consent compliance audit for the odour and effluent emission envelope. SBKJ Group commissioning support includes the Installation Qualification, Operational Qualification and Performance Qualification documentation pack tied to each audit pathway, with mill certificates, weld procedure qualification records, NDT reports and as-built drawing pack delivered for each installation.

The ARBS 2026 Sydney showcase and the SBKJ Australian engineering footprint

SBKJ Group will present the complete intensive livestock CAFO HVAC duct package at the ARBS 2026 (Air-Conditioning, Refrigeration and Building Services Exhibition) in Sydney NSW in May 2026 — the dominant trade event for the Australian HVAC, refrigeration and building services industry. The SBKJ stand will showcase the SBAL-V auto duct line in both galvanised heavy-gauge and 316L stainless variant, the SBAL-III mid-range auto duct line, the SBSF-1525 round flanger, the SB-ZF1500 stitchwelder, the SBFB-1500 spiral fitting machine, the SBPC1500 plasma cutter, the SBLR-600 longitudinal seam welder and the SBTF spiral tubeformer range — with engineering reference packs for the cattle feedlot, piggery, poultry broiler, egg layer, feed mill, anaerobic digester biogas, odour control biofilter and RTO, post-slaughter cold chain and ASHRAE 170 biosecurity isolation envelopes.

SBKJ Group is registered as an Australian engineering business at Box Hill North VIC and operates as the Australian channel for the SBKJ machinery range across the cattle feedlot, piggery, poultry broiler, egg layer, hatchery, feed mill, anaerobic digester biogas, odour control, post-slaughter cold chain and biosecurity isolation envelope. SBKJ engineers walk the JBS, Teys, Stanbroke, Mort & Co, Smithfield, Killara, Rangers Valley, SunPork, Rivalea, Linley Valley Pork, Inghams, Baiada, ProTen, Cordina, Hazeldenes, Pace Farm, Sunny Queen, Pirovic, Farm Pride, Ridley Corporation, Coprice, Riverina Stockfeeds and Lienert sites with field engineering support, commissioning support, spares and consumables support and audit-ready documentation pack delivery for each installation.

Talk to an SBKJ engineer

SBKJ Group books production slots six months ahead for JBS Australia, Teys Cargill, Stanbroke Pastoral, Mort & Co, Smithfield Cattle Company, Killara Feedlot, Rangers Valley Feedlot, SunPork Group, Rivalea (under SunPork), George Weston Foods, Linley Valley Pork, Inghams Group ASX:ING, Baiada Poultry Steggles, ProTen, Cordina Chicken Farms, Hazeldenes, Bartter Steggles, Pace Farm, Sunny Queen Australia, Pirovic Egg Farms, Farm Pride, Ridley Corporation ASX:RIC, Coprice Riverina, Riverina Stockfeeds, Wagga Stockfeeds and Lienert Australia specifications. The earliest a confirmed brief converts to FAT-ready machinery is typically 14 to 20 weeks depending on coil variant (galvanised heavy-gauge, 304L stainless, 316L stainless, 309/310S high-temperature stainless) plus 2 to 4 weeks Australian dispatch from Box Hill North VIC. Talk to an SBKJ engineer for an itemised landed-cost worksheet that ties scope to scope and standard to standard.