K-12 Schools HVAC Duct Guide — Public, Catholic & Independent — Classrooms, STEM Labs, Library, Gym & Theatre

Why K-12 HVAC is its own discipline — distinct from childcare and tertiary

An Australian K-12 school sits between two other published SBKJ guides — the childcare and early learning guide for under-5s and the university and TAFE workshop and engineering lab guide for tertiary education. K-12 is neither. Children aged 5 to 18 are not infants, and a Year 11 chemistry teaching lab is not a university research bench. The codes that bracket K-12 HVAC — AS 1668.2, AS 2107, AS 2243, the NCC, the state Department of Education technical specifications, the post-COVID Indoor Air Quality program — combine into a problem space that deserves its own engineering treatment.

This guide is the playbook SBKJ engineers walk through with mechanical contractors fitting out school projects across Australia, whether the client is School Infrastructure NSW delivering a new public primary school in Western Sydney, the Catholic Education Office of Melbourne delivering a Year 7-12 secondary college in Brunswick, the Victorian School Building Authority rebuilding a regional secondary school in Bendigo, or a Headmaster's office at Geelong Grammar tendering a new STEM and senior school building at Corio. The standards converge: AS 1668.2 for outdoor air, NCC Class 9b for the building, AS/NZS 4254 for the ductwork, AS 2107 for acoustics, AS 2243 for the science laboratories, AS 1851 for the fire dampers, AS 1428.1 for accessibility, and the state Department or diocese technical specification for everything not specified in the codes. Get any one of those layers wrong and the school fails compliance, runs hot in summer or cold in winter, fails its post-COVID Indoor Air Quality audit, or — worse — a Year 12 chemistry experiment goes wrong inside a fume cupboard that was never properly commissioned.

The good news: the design problem is bounded. Australian K-12 schools share a known cohort of room types — general classrooms, specialist classrooms, science laboratories, libraries, school halls, gymnasiums, music rooms, theatres, art rooms, design and technology workshops, food technology rooms, canteens, sick bays, administration, staff rooms and toilet blocks. Once the schedule of rooms is set, the ductwork specification follows mechanically. This guide walks through that specification room by room, with the regulatory hook for each decision and the practical SBKJ-line implications, then closes with a sector-by-sector walk through the operator landscape that drives the specifications.

The Australian regulatory stack for K-12 schools

Eight layers of regulation drive HVAC ductwork decisions in an Australian K-12 school project. Most consultants name three or four. The eight layers, in priority order, are:

1. National Construction Code (NCC) / Building Code of Australia (BCA). K-12 school teaching buildings are classified as Class 9b assembly under NCC Volume One, with Class 6 layered for any commercial kitchen attached to a canteen or refectory, Class 9a for any sick bay with treatment beds, Class 9c for boarding house residential where applicable, and Class 10b for groundskeeper storage outside the main envelope. Class 9b triggers mechanical ventilation to AS 1668.2, fire compartmentation, smoke management to AS 1668.1 where applicable, exit provisions and accessibility under the Premises Standards 2010.
2. AS 1668.2 — Mechanical ventilation in buildings. Table 3.2 sets outdoor air rates by space type — 10 L/s/person for general classrooms, 12 L/s/person for libraries, 25 L/s/person for gymnasiums during peak PE class use, 12 L/s/person for theatres at full house, 12 L/s/person for canteens. Section 5 covers commercial kitchen exhaust. The standard is the mechanical ventilation backbone for the entire school.
3. AS 4254 — Ductwork for air handling systems. Parts 1 and 2 cover flexible and rigid ductwork respectively. AS 4254.2 sets material gauges, joint construction, leakage classification (Class A is the tightest, Class C the loosest) and pressure testing. School projects typically specify Class A for low-leakage paths (fume hood exhaust, kitchen exhaust) and Class B for general supply and return.
4. AS 1530.4 — Fire resistance of building elements. Provides the fire-rating test method for any duct passing through a fire-rated boundary. The duct or duct sleeve assembly must achieve the FRL of the construction it penetrates — typically 60/60/60 or 90/90/90.
5. AS 2243 series — Safety in laboratories. Eight parts cover laboratory safety. For a K-12 school, Parts 1 (general planning), 2 (chemistry), 3 (microbiological — PC1, occasionally PC2 in senior labs) and 8 (fume cupboards) are the parts that matter. AS 2243.8 is the most-cited and prescribes 0.5 m/s ± 0.1 m/s face velocity at the design sash height for every fume cupboard.
6. AS 2107 — Acoustics — Recommended design sound levels and reverberation times for building interiors. Sets ambient internal noise targets by space type — NC-30 to NC-35 for classrooms, NC-30 for libraries, NC-25 to NC-30 for theatres and music rooms, NC-35 to NC-40 for gymnasiums in use. AS 1276 covers sound transmission class for partition design that complements the acoustic ductwork strategy.
7. AS 1851 — Routine service of fire protection systems and equipment. Sets the annual drop-test requirement for fire and smoke dampers, the inspection frequency for fire-rated penetrations and the documentation expected at essential safety measures audits.
8. State Department of Education technical specifications and Department of Education school infrastructure programs. Each state publishes a standard mechanical specification through the school infrastructure agency — Schools Infrastructure NSW for NSW, Victorian School Building Authority (VSBA) for Victoria, Queensland Department of Education Building and Asset Services for QLD, WA Department of Education for WA, SA Department for Education for SA, ACT Education Directorate for the ACT, NT Department of Education for the NT, TAS Department for Education Children and Young People for Tasmania. These specifications add state-specific positions on AHU types, BMS interfacing, NABERS Energy targets, post-COVID CO2 monitor specifications and accessibility compliance.

Additional standards that surface on specific spaces: AS 1940 (chemistry solvent storage), AS/NZS 60079 (intrinsically safe electrical zone in chemistry storage where solvents are kept), AS 1657 (platforms — mezzanine plant rooms), AS 2118 (sprinkler), AS 1742 (traffic and signage — coordination with school car park HVAC), AS 1428.1 (DDA accessibility), AS/NZS 1428.4 (wayfinding for vision-impaired students and visitors), AS 1276 (acoustic transmission class), AS 1530.4 (fire-rated test method), ASHRAE Standard 62.1 (international cross-reference for outdoor air) and the post-COVID schools ventilation guidance published by each state Department.

Post-COVID classroom ventilation — the change that reset every state specification

The most significant change to K-12 HVAC specification in the last two decades is the post-COVID Indoor Air Quality program rolled out across every Australian state. Between 2020 and 2023 every state Department of Education funded a CO2 monitor rollout, updated its classroom ventilation guidance and audited existing schools for ventilation effectiveness. The legacy of that program is now embedded in every new-build and refurbishment mechanical specification.

The Victorian Department of Education and Training distributed more than 51,000 CO2 monitors to Victorian public schools — a benchmark figure that is now cited in mechanical briefs across the country. NSW Department of Education ran an Air Purifier and CO2 Monitor program through Schools Infrastructure NSW. Queensland Department of Education funded ventilation upgrades through its existing capital works program. The ACT Education Directorate and the South Australian Department for Education ran similar programs. The legacy specification positions are remarkably consistent across the states:

• CO2 monitoring in every learning space. A wall-mounted NDIR CO2 sensor at 1.2 to 1.5 m above floor level, away from supply diffusers and exterior walls, with a teacher-visible display or a BMS-linked dashboard. Trigger at 1,200 ppm, target below 1,000 ppm, aspirational below 800 ppm in primary classrooms.
• Outdoor air rate conservatism. The AS 1668.2 minimum of 10 L/s/person for general classrooms is now routinely overdesigned to 12 to 15 L/s/person in new mechanical briefs, with demand-controlled ventilation trimming back during low occupancy.
• MERV 13 filtration minimum. Previously MERV 8 was acceptable; post-COVID specifications standardise on MERV 13 as the minimum for any AHU serving an occupied learning space. MERV 14 to 15 is increasingly specified for school halls and assembly spaces at high occupancy density.
• Pre-occupancy purge. A 60 to 120 minute pre-occupancy purge cycle running 100 percent outdoor air at full design flow before the first bell on every school day, plus an extended purge on the first day of each term.
• Continuous monitoring with auditable logging. Continuous CO2, temperature and humidity logging accessible to the school facilities manager via the BMS. Some state Departments now make the data accessible to parents through portal dashboards.
• Outdoor air verification at commissioning. Direct measurement of outdoor air at the AHU rather than calculated from damper position. Often required as part of practical completion sign-off.

The implications for ductwork are direct. The outdoor air duct sizing has gone up by 20 to 50 percent over pre-COVID baselines. The supply trunks are larger to keep face velocity within the AS 2107 acoustic targets at the higher airflow. The AHU plant rooms are larger to accommodate the larger AHU and the MERV 13 filter bank. The energy recovery layer (heat wheel or plate exchanger) on outdoor air pays back faster than it did pre-COVID. For mechanical contractors and ducting fabricators, the volume of duct per square metre of school floor area is meaningfully higher than it was five years ago.

General classroom — the largest single zone count

General classrooms are the largest single zone count in any K-12 school — a typical 800-student secondary school will have 35 to 50 general classrooms, plus specialist rooms. The HVAC system has to handle peak occupancy through five 50-minute teaching periods per day, with breaks for recess and lunch when the room is empty, plus extended hours for after-school care, parent-teacher nights, exam supervision and after-hours community use.

Design conditions. 22 to 24°C dry bulb, 40 to 60 percent relative humidity, NC-30 to NC-35 acoustic target. AS 1668.2 outdoor air at 10 L/s/person minimum, post-COVID specifications design to 12 to 15 L/s/person. Demand-controlled ventilation modulates the outside air via CO2 sensor with a 1,000 ppm setpoint, 1,200 ppm alarm.

Air change rate. Typical primary classroom 4 to 6 ACH; secondary classroom 5 to 7 ACH. Higher ACH is acceptable acoustically only if face velocities are managed below the noise threshold. The bottleneck is acoustic, not flow capacity.

Multi-zone VAV with reheat. Classrooms in east-west oriented buildings experience large solar gain differentials. Multi-zone VAV with reheat (or DOAS plus terminal heat pumps) handles the differential without overcooling shaded rooms to satisfy sun-exposed rooms. Each classroom is its own zone with a wall thermostat at 1.5 m height, occupancy sensor for after-hours override, and CO2 sensor as described.

Diffuser layout. Throw across the room rather than down onto student desks. Supply face velocity below 2.5 m/s, return below 2.0 m/s. Return grilles located centrally, away from doorways where short-cycle effects from corridor air infiltration disrupt the room balance. Avoid linear slot diffusers above the teacher zone (cold air drop onto the teacher during prolonged standing).

Acoustic target NC-30 to NC-35. NC-30 corresponds to approximately 35 dBA — quiet enough that a teacher's normal speaking voice carries to the back row without amplification. NC-35 is the upper bound for general classrooms. The targets are routinely measured during state Department of Education commissioning audits. Achieving them reliably requires the duct sizing discipline above, an inline attenuator at each VAV terminal, 25 mm internal acoustic lining over the last 6 to 9 m of supply duct, and vibration isolation on the AHU.

Lighting interlock and after-hours operation. The classroom HVAC operates on a programmed schedule tied to bell times, with an occupancy sensor permitting after-hours override for teacher preparation and OSHC use. The HVAC drops to setback (24 to 26°C cooling, 18 to 20°C heating, minimum outdoor air) during nights, weekends and school holidays.

Where the school operates after-school care, parent-teacher nights, evening adult education or community use, the AHU schedule must extend to cover those hours. Many post-COVID specifications now mandate continuous fan-only operation 24/7 with minimal outside air during unoccupied periods to provide background ventilation and minimise mould risk in humid coastal climates.

Specialist classrooms — art, music, languages, drama and computer

Specialist classrooms are general classroom variants with additional requirements driven by the subject taught. The HVAC pattern carries over from general classroom with adjustments: art rooms add local extract for the kiln (1,100°C firing generates toxic glaze fumes including lead — dedicated stainless steel extract to roof) plus solvent storage to AS 1940 and ceramics dust extraction. Music rooms and ensemble rooms target NC-25 to NC-30 acoustic with isolated supply path, no shared trunk between adjacent rooms (cross-talk prevention), 50 mm internal acoustic lining over the full supply branch length, and acoustic doors with full perimeter seals. Drama studios target NC-30 with dedicated heat extract for the theatrical lighting grid where present. Computer labs carry a significant sensible heat load (50 to 100 PCs generates 10 to 15 kW) requiring dedicated AHU or VRV indoor unit sized for IT load plus occupancy, with redundant cooling for any server room within the lab. Library media centres combine library acoustic requirements (NC-30) with PC heat load — refer to the library, museum and archive guide for preservation aspects.

STEM science laboratory cluster — where the highest engineering precision sits

The STEM science laboratory cluster is the highest-engineering-precision part of any K-12 school. A typical Year 7-12 secondary school will have three to six science labs in the cluster — chemistry, biology, physics, a multi-purpose junior science lab, often a senior physics or applied science lab, and increasingly a STEM workshop with 3D printers and CNC equipment. Each room has different ductwork requirements, and the cluster shares a single fume hood exhaust manifold to the roof. Getting the cluster wrong is one of the few HVAC failures that can put students at risk during a chemistry practical.

Chemistry teaching laboratory

The chemistry teaching lab is the most demanding room in the cluster. AS 2243.2 governs the chemistry lab; AS 2243.8 governs the fume cupboards within it.

Design conditions. 22 to 24°C dry bulb, 40 to 50 percent RH, 8 to 10 ACH with 100 percent outside air (no recirculation). The room is held slightly negative relative to the adjacent corridor — typically minus 5 to minus 10 Pa — so that any fume spill migrates away from learning spaces and toward the exhaust path. NC-40 acoustic target (higher than general classroom because fume cupboard fans contribute baseline noise that the duct system alone cannot eliminate).

Fume cupboard face velocity. AS/NZS 2243.8 requires 0.5 m/s ± 0.1 m/s at the design sash height. Most school specifications go nominal 0.5 m/s with an alarm low at 0.4 m/s. Variable-air-volume cupboards modulate exhaust to hold face velocity constant as the sash is raised or lowered — the more common contemporary specification, especially where the school runs an energy-conscious facility brief and avoids the constant-volume waste of a fixed-sash design.

Exhaust ductwork. The fume cupboard exhaust runs in dedicated 304 stainless steel from the cupboard outlet to roof discharge — no recirculation, no AHU return path, no plenum sharing with comfort ductwork. Welded longitudinal seams for low leakage. Each cupboard typically draws 0.7 to 1.5 m³/s at design sash. A four-cupboard chemistry lab manifolds to a single roof stack with redundant fans (N+1 configuration is standard practice — one operating, one standby with automatic switchover on fan failure).

Fume cupboard alarm system. Continuous face velocity monitor at each cupboard, audible and visual alarm at low velocity, BMS integration with central fault logging. The alarm should mute briefly when the teacher initiates a sash movement and re-arm automatically.

Chemical storage. A separate chemical storage room adjacent to the lab, sized to AS 1940 for the volume and class of chemicals held. Where flammable solvents (Class 3) are stored, the storage room is intrinsically safe to AS/NZS 60079 with the appropriate zone classification (typically Zone 2 for the room, Zone 1 inside the cabinet) and dedicated extract at 6 to 10 ACH continuous. The extract discharges to roof, separate from the fume cupboard manifold to avoid commingling of acids and solvents.

Wet bench services. Each lab bench has integrated services — water, gas, electricity, vacuum. The gas supply is typically natural gas to AS 5601, with shut-off valves at the door and emergency shut-off at the teacher's desk. Gas leak detection above the LEL (CH4 1.25 percent LEL trigger) interlocks the lab into emergency ventilation mode and isolates the gas supply at the meter.

Spill response. Spill kits at the door, eyewash stations to AS 4775 within 6 m of the work area, emergency shower at the door, drench shower interlock alarm. The HVAC contribution is the maintained negative pressure to confine any chemical aerosol generated during a spill response to the lab and its exhaust path.

Biology teaching laboratory

The biology lab is closer to a general classroom than the chemistry lab but adds specific extracts for the biological work conducted.

Design conditions. 22 to 24°C, 40 to 60 percent RH, 6 to 8 ACH. PC1 containment per AS/NZS 2243.3 for most school biology — sufficient for handling non-pathogenic organisms (yeast, plant tissue culture, common soil microbes). Some senior biology labs (Year 11 and 12 IB, VCE Biology, NSW HSC Biology, QCE Biology, WA ATAR Biology) run small-scale PC2 work — handling of E. coli K-12 strains for genetic engineering practicals — under the supervision of teachers trained in PC2 procedures.

Autoclave. A small steam autoclave for sterilising glassware and disposing of biological waste generates humidity that requires local extract — typically 15 to 25 L/s direct to outside on a dedicated extract, with the extract grille over the autoclave. Where the autoclave is located in a service room adjacent to the lab, the extract is in the service room.

Biological Safety Cabinet (BSC). Where the lab includes a Class II Type A2 BSC for PC2 work, the cabinet HEPA exhaust is plumbed through the room return air path (Type A2 — recirculation acceptable inside the cabinet, room exhaust acceptable). The room AHU does not recirculate to other rooms — once-through air with full outside-air supply. Where a Class II Type B2 BSC is used (full exhaust to outside), a dedicated stainless duct to roof discharge.

Specimen storage. Refrigerators and freezers for specimens — standard refrigerator sensible and latent load applies. Where formalin-preserved specimens are stored (dissection program), a vented cabinet to capture formaldehyde leakage — formaldehyde STEL is 1 ppm, and an unvented cabinet of preserved specimens in a closed room will exceed STEL within hours.

Dissection bench. Where the lab is used for dissection practicals, a downdraft or canopy extract over each bench at 0.5 m/s capture velocity removes formaldehyde and biological odour at source. Dedicated stainless duct to roof discharge.

Physics teaching laboratory

The physics lab is the closest of the science labs to a general classroom. The HVAC requirements are general classroom plus local extract for specific demonstrations.

Design conditions. 22 to 24°C, 40 to 60 percent RH, 5 to 7 ACH. NC-35 acoustic target — same as general classroom. MERV 13 supply filtration.

Laser demonstration extract. Where the school physics program includes laser cutting demonstrations or laser experiments using more than Class 2 lasers, local extract at the work area captures any vapour or particulate generated. AS/NZS IEC 60825.1 governs the laser safety; the HVAC contribution is the local extract.

3D printer extract. Most contemporary physics or STEM labs include a 3D printer fleet — typically four to twelve FDM printers running ABS, PLA or composite filaments. ABS printing emits formaldehyde, styrene and ultrafine particles (UFP). PLA is lower-emission but still produces UFP. A dedicated extract canopy or enclosed cabinet over each printer at 0.5 m/s capture velocity removes the emissions at source. Dedicated stainless duct to roof discharge.

Cosmic ray, radiation and radioactivity demonstrations. Where the school holds small calibration sources for radioactivity demonstrations (typically alpha, beta and gamma sealed sources at very low activity), the room is registered with the state radiation regulator and the storage is per AS/NZS 2243.4. The HVAC contribution is normal classroom ventilation — sealed sources do not generate airborne contamination.

STEM workshop, design and technology — 3D printer, CNC, laser cutter

The STEM workshop is increasingly the defining specialist space in contemporary K-12 schools — a hybrid design and technology room with 3D printers, CNC milling, laser cutting, electronics assembly, and traditional joinery and metalwork. Each technology has its own extract requirement.

• 3D printer fleet. Extract at each printer envelope at 0.5 m/s capture velocity capturing formaldehyde, styrene and UFP. Where the printers are in a dedicated cabinet (typical for resin SLA printers), the cabinet itself provides containment and a single extract serves the cabinet bank.
• CNC milling and routing. Downdraft tables and tool-tip extract capture wood dust, MDF dust, aluminium chips and coolant aerosol. Wood dust extract per AS 4024 dust collection — typically 2,000 to 4,000 L/s at the collector for a four-station workshop, with the collected dust managed by a bag house or cyclone.
• Laser cutter. CO2 laser cutters generate combustion products (CO, formaldehyde, hydrogen chloride from chlorinated plastics, acrolein from acrylic). Dedicated extract at the cutter envelope at the manufacturer's specified flow rate (typically 200 to 600 L/s) with HEPA and activated carbon filtration on the discharge.
• Electronics assembly. Solder fume extraction at each workstation — typically a small bench-top extractor with HEPA and activated carbon, locally vented or trunk-vented to roof. Lead-free solder is mandatory in schools (RoHS).
• Joinery and metalwork. Refer to the broader workshop guide — wood dust extraction, weld fume extraction (where senior students undertake basic welding training), grinding dust extract.

Library and reading room — preservation overlaps with study comfort

The library has two HVAC jobs: keep the readers comfortable and quiet, and keep the book collection in conservation-appropriate conditions. The two objectives overlap most of the time but diverge at the margins — archive collections require tighter humidity control than the comfort of human readers requires.

Design conditions for the main reading room. 21 to 23°C, 45 to 55 percent RH, NC-30 acoustic, CO2 below 800 ppm aspirational during peak after-school study periods. The slightly cooler temperature than a general classroom (21 to 23 vs 22 to 24) supports paper preservation and reduces the load on cooling during peak study sessions when the room fills with senior students.

Air change rate. 3 to 5 ACH — lower than a classroom because the occupancy density is typically lower, but tightly held humidity is more important than high air change.

Diffuser layout. Avoid direct flow onto reading tables — drafts on senior students during multi-hour study sessions generate complaints. Avoid flow over open book displays — direct airflow over open pages accelerates paper deterioration.

Acoustic target NC-30. Sleep room acoustic level — the library should be quiet enough that the AHU is not audible during silent study. Sized ductwork, attenuators on each branch, and acoustic lining over the supply branches achieve the target.

Archive and special collection zone. Where the library holds an archive, special collection, rare book collection or school history archive, that zone runs as a separate HVAC sub-zone with tighter humidity control — 50 percent RH ± 5 percent — and lower temperature (18 to 20°C) for paper preservation. The materials of construction for the archive ducting include corrosion-resistant fasteners and gaskets to manage long-term off-gassing concerns. For deeper detail refer to the library, museum and archive HVAC duct guide.

IT and PC infrastructure. Library media centres carry a significant PC fleet, library catalogue terminals and printing stations. Separate HVAC sub-zone for the IT density, with cooling sized to the PC heat load plus occupancy plus solar gain.

Gymnasium and indoor sports hall — high occupancy, ball impact, displacement ventilation

The school gymnasium serves multiple functions — PE class delivery during the school day, after-school sports training, weekend competition, school assemblies, drama productions where there is no dedicated theatre, exam supervision for large cohorts, and community use outside school hours. The HVAC system has to handle the full envelope, with the peak load being a Year 7 PE class doing high-intensity interval training in 35°C ambient.

Design conditions. 18 to 22°C during PE use (lower than other spaces because the occupants are exercising and generating significant body heat), 22 to 24°C during sedentary use (assemblies, exams). 40 to 60 percent RH. NC-35 to NC-40 acoustic target.

Ventilation rate. 25 L/s/person fresh air during peak PE use per AS 1668.2 Table 3.2 (a significant step up from 10 L/s/person in classrooms — reflecting the higher metabolic load of exercising occupants). At 60 students plus three teachers, that is 1,575 L/s of fresh air for a typical PE class.

Air change rate. 4 to 6 ACH on the gymnasium volume during peak use. Higher ACH during assembly when the room is filled to standing capacity (1,000+ students for some independent schools' senior assemblies).

Displacement ventilation. The dominant gymnasium design pattern is displacement ventilation — large low-sidewall supply diffusers introducing cool conditioned air at low velocity, allowing the thermal plume from exercising bodies to rise and exit at high-level return grilles at the ridge. This pattern delivers comfort to the playing surface while exhausting heat and CO2 from the upper volume.

Diffuser ball-impact protection. Low-level diffusers in a gymnasium must be ball-impact rated — drum-louvre or perforated face plates with steel guards rated for direct hits from basketballs, soccer balls, dodgeballs and the occasional cricket or hockey ball. Avoid linear slot diffusers at ball-strike height. The state Department specifications typically prescribe drum-louvre diffuser face plates and impact-resistant flush-mounted return grilles.

External wall louvre placement. Where outdoor air is drawn through external wall louvres at low level, locate the louvres at side play position so ball strikes do not impair the louvre face or the bird mesh behind it. Higher-level wall louvres avoid the ball strike risk but require a longer outdoor air duct run.

Acoustic target NC-35 to NC-40. Higher than a classroom because the gymnasium is acoustically reverberant by nature and the AHU noise is masked by the activity noise. The lower bound (NC-35) is desirable for assembly use where speech intelligibility matters.

Humidity management. Gymnasiums in humid coastal climates (Brisbane, Sydney, Townsville, Cairns, Darwin) experience high latent loads from sweating occupants. Specify dehumidification capability on the AHU coil and verify against the peak humid-day cooling design condition. Mould management on the gymnasium ceiling and acoustic linings depends on this.

Court flooring interaction. Sprung timber sports floors expand and contract with humidity. Tight humidity control (40 to 60 percent RH) protects the floor and prevents the expansion gaps from closing during humid weather or opening during dry weather.

School theatre and performing arts auditorium

Most independent schools and a growing number of public and Catholic schools include a dedicated school theatre or performing arts auditorium. The space supports the school drama and music programs, end-of-year productions, speech nights, school assemblies on a smaller scale than the full-school gymnasium, and community use through the school's community-engagement program.

Design conditions. 22 to 24°C, 40 to 60 percent RH, NC-25 to NC-30 acoustic target — substantially tighter than a classroom because the auditorium is acoustically critical for the performance use.

Ventilation rate. 12 L/s/person at full house per AS 1668.2 Table 3.2. For a 400-seat auditorium that is 4,800 L/s — about 17,000 m³/h, requiring a substantial dedicated AHU. Demand-controlled ventilation modulates from the design rate during full house down to background rate during rehearsal or partial occupancy.

Displacement ventilation under raked seating. The dominant theatre design pattern is displacement ventilation with supply diffusers under each seat or in the riser of each step in the rake, allowing cool conditioned air to bathe the audience at low velocity. High-level return at the ceiling exhausts the heat and CO2 plume. This pattern delivers excellent comfort at remarkably low fan energy because the supply air does not have to mix the entire auditorium volume — it just has to keep the occupied zone comfortable.

Acoustic target NC-25 to NC-30. NC-25 is recording-studio quiet. Hitting NC-25 in a 400-seat auditorium with a 5,000 L/s AHU is a serious engineering challenge — it requires very large ducts (face velocity below 4 m/s in supply, below 3 m/s in return), substantial attenuation (typically two attenuators in series on each supply branch with 35 dB combined insertion loss), thick acoustic lining over long duct runs, and vibration isolation on the AHU. The AHU itself is typically located in a remote plant room with the ductwork run through acoustic plenums.

Reverberation time. AS 2107 specifies a reverberation time of 0.8 to 1.2 seconds for school auditoriums depending on use — speech-focused (school assembly) at the lower end, music-focused (orchestral concert) at the upper end. The acoustic design of the room interior (wall and ceiling treatments) drives the reverberation time; the HVAC contribution is keeping the background noise floor low enough that the reverberation is audible against the noise floor.

Fly tower extract. Where the theatre includes a fly tower for backdrop and curtain movement, the fly tower itself is a tall vertical volume requiring heat extract — typically a roof-mounted exhaust fan with smoke spill capability per AS 1668.1 and a make-up air supply at low level from the stage.

Dressing room ventilation. Dressing rooms behind the stage are typically classified the same as the auditorium for ventilation rate, with the addition of a hair-styling extract above any mirror station (hairspray VOCs) and a make-up area extract.

Dimmer rack room. The dimmer rack room hosts the theatrical lighting control and the dimmer racks — significant heat load (typically 5 to 15 kW depending on rig size) that requires a dedicated AHU or VRV indoor unit. Plenty of school theatres have had a midwinter performance disrupted by an overheating dimmer rack tripping out — design the heat rejection conservatively.

Smoke management. Auditoriums above the NCC smoke spill threshold (typically 1,000 occupants for assembly buildings) require smoke spill ventilation per AS 1668.1. The smoke spill ductwork is specified to survival temperature with fire-rated construction. See the cinema, theatre and entertainment HVAC duct guide for the detail.

School hall — the multi-purpose assembly space

The school hall is the multi-purpose assembly space found in almost every Australian school — used for full-school assemblies, exam supervision, parent-teacher nights, performances, indoor sport during inclement weather, OSHC activity space and community hire. Design conditions: 22 to 24°C during assembly and exams, 18 to 22°C during indoor sport use, 40 to 60 percent RH, NC-35 acoustic during occupied use. Ventilation 12 L/s/person at full house per AS 1668.2 — a 600-occupant hall is 7,200 L/s of outdoor air on a large dedicated AHU. The mixed-use challenge is that the hall is sometimes used as a gymnasium (displacement ventilation with ball-impact protection), sometimes as a theatre (raked seating displacement), sometimes as an exam venue (quiet comfort) and sometimes as an assembly venue (voice intelligibility). Most state Department specifications resolve this with a hybrid design — high-level supply diffusers with adjustable throw, low-level return, ball-impact protection on accessible faces, and substantial acoustic attenuation. Schools that hire the hall for community use need an after-hours AHU schedule and BMS configuration that supports evening operation without running the whole-school plant.

Canteen, tuckshop and refectory — commercial kitchen exhaust meets school canteen

Most Australian K-12 schools include some form of food service — a tuckshop running for recess and lunch in primary schools, a fuller canteen or refectory in secondary and senior schools, and in boarding schools a full commercial dining hall. Where cooking is undertaken on site, AS 1668.2 Section 5 commercial kitchen exhaust requirements apply with NFPA 96 as international cross-reference. The cooking line grease hood is sized for 0.4 to 0.5 m/s capture velocity, fabricated in welded 304 stainless steel on welded longitudinal seams for grease integrity, fire-rated kitchen exhaust riser through the building, cleanouts at every change of direction, grease trap at discharge. Dedicated make-up air at 80 to 90 percent of exhaust rate maintains slight negative pressure relative to adjacent dining and learning areas — Brisbane and Darwin schools size make-up air with substantial dehumidification capacity. Dining area is standard classroom-level comfort (22 to 24°C, 40 to 60 percent RH, NC-35 to NC-40 acoustic, MERV 13 supply) on a dedicated AHU separate from the kitchen exhaust. Dishwashing area needs local extract over the dishwasher at 25 to 50 L/s/m². Where gas cooking is installed, gas detection above the LEL (CH4 1.25 percent LEL trigger) interlocks the kitchen ventilation into emergency mode and isolates the gas supply at the meter, with CO monitoring at 30 ppm OEL and audible alarm. For full detail see the commercial kitchen exhaust guide.

Toilet, change room, shower and sick bay

AS 1668.2 mandates mechanical extract for toilet, change room and shower facilities: 25 L/s per WC pan and 25 L/s per urinal stall as continuous extract direct to outside (no recirculation, negative pressure relative to adjacent learning spaces), 30 L/s per shower head for humidity, and 10 L/s/m² for the change room volume during use. Extract grilles locate to capture odour and humidity at source — above the WC pan, above the shower, in the upper volume of change rooms. Where the toilet block serves the gymnasium, the extract sizing combines with the change room — typically a single fan handling the whole envelope at worst-case combined load.

The sick bay (also called the first aid room or wellbeing room in contemporary independent school terminology) hosts unwell students, minor first aid for sports injuries and confidential counsellor discussions. Where it includes a treatment bed, it may be classified Class 9a health care under the NCC. Design conditions: 22 to 24°C, 40 to 60 percent RH, NC-30 acoustic, MERV 13 filtration minimum (HEPA H13 for any isolation room within the sick bay), 10 to 15 L/s/person fresh air (slightly elevated over classroom because of elevated infectious-illness exposure). Some larger schools include a discrete isolation room running as a negative-pressure zone with HEPA H13 supply and dedicated exhaust direct to outside — the pattern is identical to a hospital airborne-infection isolation room at a smaller scale, see the hospital and healthcare HVAC duct guide. The counsellor room targets NC-30 with no shared ductwork to adjacent classrooms (conversation privacy).

Administration, staff room, server room and plant rooms

Administration spaces are standard office-grade HVAC — 22 to 24°C, 40 to 60 percent RH, NC-35 to NC-40 acoustic, 10 L/s/person outdoor air per AS 1668.2 Table 3.2, MERV 13 filtration. Separate AHU or AHU zone from the learning room cluster because the operating schedule is different (administration runs longer hours). Reception and parent waiting areas need slightly elevated outdoor air for morning drop-off and parent-teacher event peaks. Principal's office and senior administration target NC-30 with acoustic isolation for confidential conversations. Photocopy areas need local extract for ozone emission from older laser printers (OEL 0.1 ppm). Server rooms and IT closets need dedicated cooling for the networking and storage heat load with N+1 redundancy for rooms hosting business-critical infrastructure.

Lift machine rooms (mandatory for any school with more than ground floor under Premises Standards 2010 accessibility) require heat extract — 30°C maximum target since lift control equipment derates above 35°C. Plant rooms hosting AHUs, boilers and chillers require their own ventilation — typically natural louvres for air-source plant, mechanical extract where heat or gas appliances are present. Gas-fired boilers require dedicated combustion air, gas detection and emergency ventilation interlock per AS 5601.

Boarding house dormitory and preschool — where applicable

Many independent schools and some Catholic schools include a boarding house — residential accommodation for regional Australian and international students. The boarding house is classified Class 9c residential care or Class 3 residential accommodation under the NCC. Design conditions: 21 to 23°C during sleep hours, 22 to 24°C during study/recreation, 40 to 60 percent RH, NC-30 acoustic in sleeping rooms. Ventilation 7.5 to 10 L/s/person per AS 1668.2 for residential accommodation. Acoustic isolation between rooms — duct strategy similar to a hotel or aged care residence with no shared trunks (cross-talk prevention). Refer to the hotel and hospitality HVAC duct guide and the aged care, retirement and disability HVAC duct guide for related residential patterns. Bathroom and amenities extract per the main school facility. Boarding dining hall follows the commercial kitchen exhaust pattern above. Study halls and tutorial rooms are treated as general classrooms.

Many K-12 schools include a preschool, kindergarten or pre-prep year (Reception, Foundation, Kindy depending on state). The regulatory classification governs: where the preschool is operated under the school's Department of Education registration, the K-12 HVAC pattern applies. Where the preschool is operated as a regulated Education and Care Service under the National Quality Framework — typical of independent school preschools and stand-alone kindergartens — the childcare HVAC pattern applies, including 12 L/s/person AS 1668.2 rate, NQS Quality Area 3 evidence requirements and 25 L/s nappy change extract where toileting is in transition. Refer to the childcare and early learning guide.

After-hours care and OSHC integration

Out of School Hours Care (OSHC) operates 0700 to 0900 in the morning and 1500 to 1830 in the afternoon, plus pupil-free days and school holidays. Major operators (Camp Australia, TheirCare, Junior Adventures Group) typically operate within the school's existing facilities. The HVAC implications: the school AHU must run during the OSHC operating window with a 0630 cold start before 0700 occupancy, continuing through 1830 (pre-COVID 0800 to 1600 schedules are no longer sufficient); outdoor air must hold during OSHC since the space runs at the same or higher density (demand-controlled ventilation tied to CO2 monitoring handles this automatically); acoustic targets are lower priority during recreational use; and the holiday setback strategy must accommodate OSHC operation in the spaces actually used while the rest of the school runs in deep setback. For the regulated childcare aspects of OSHC under the NQF, refer to the childcare and early learning guide.

Accessibility and DDA — AS 1428.1 and the Premises Standards 2010

The Disability (Access to Premises — Buildings) Standards 2010 apply to all new and significantly upgraded Australian school buildings. The HVAC ductwork implications concentrate on a few decisions: diffuser and grille height and thermostat sensor placement must respect AS 1428.1 accessibility reach ranges (700 to 1,200 mm above floor for controls accessible to wheelchair-using staff); lift machine room ventilation must support continuous lift operation since heat-related shut-downs block accessible movement between floors; AS/NZS 1428.4 wayfinding for vision-impaired users requires auditory signalling (lift chimes, fire alarm) that is not masked by AHU noise — the acoustic NC-30 to NC-35 classroom target supports this directly; and schools with significant autism spectrum or sensory processing populations specify lower acoustic targets (NC-25), low air velocity at occupant level (below 0.15 m/s) and perforated face diffusers rather than linear slots for lower regenerated noise.

Acoustic targets and the AS 2107 specification

AS/NZS 2107:2016 is the controlling acoustic standard for Australian school interiors. The recommended internal noise levels by space type: primary and secondary classroom NC-30 to NC-35; library reading room NC-30; school auditorium and theatre NC-25 to NC-30; music room and ensemble room NC-25 to NC-30; recording studio within the music wing NC-25; school hall and gymnasium in active use NC-35 to NC-40; sensory and special education classroom NC-25; administration office NC-35 to NC-40; counsellor and wellbeing room NC-30; sick bay NC-30; canteen and dining hall NC-35 to NC-40; science laboratory NC-40 (fume cupboard fan noise governs); design and technology workshop NC-45 to NC-50 (machinery noise governs); boarding house dormitory sleeping room NC-30. Hitting these targets reliably depends on duct sizing discipline, attenuator selection and acoustic lining as covered in the acoustic HVAC duct lining and attenuator guide. AS 1276 covers the partition acoustic transmission class — the HVAC contribution is keeping background noise low enough that the partition performance is audible against the noise floor.

School holiday setback and energy benchmarking

Australian K-12 schools run roughly 200 student days per year. The HVAC system manages two operating modes: occupied (school day, 200 days) and unoccupied (165 days — the larger fraction). Deep school holiday setback closes outside air dampers to minimum infiltration, cycles AHU fans off for unoccupied hours, relaxes supply temperatures by 4 to 6°C, disables demand-controlled ventilation and reduces energy to 30 to 50 percent of school day operation. A two-hour 100 percent outdoor air pre-occupancy purge on the morning of the first return-to-school day brings the building to design conditions before students arrive — the first day of Term 1 (early February) is often the highest-risk day for indoor air quality after the long Christmas shutdown.

The NABERS Energy for Schools rating tool rates whole-school energy intensity in MJ/m²/year. Higher star ratings push designers toward variable air volume, demand-controlled ventilation, full economiser cycle, low static pressure design (target external static under 250 Pa), and tight-leakage TDF flange duct (Class A to AS 4254.2). A 5-star or 5.5-star NABERS Energy rating is the contemporary target for new public school builds in NSW, Victoria, the ACT and Queensland. Some independent schools are pursuing Climate Active carbon neutral certification as a parent-marketing differentiator — the HVAC contribution is energy efficiency (NABERS rating), embedded carbon in the ductwork (galvanised steel has lower embedded carbon than aluminium) and R32 refrigerant in split AC.

SBKJ machine configuration for K-12 school fabrication

For Australian K-12 school project work, SBKJ engineers recommend the following standard machine configuration for the mechanical contractor or ducting fabricator delivering the work:

• SBAL-V galvanised auto duct line — the workhorse. The SBAL-V handles galvanised steel from 0.5 to 1.5 mm thickness in the SBAL-V-1250J (1,250 mm coil width) or SBAL-V-1500J (1,500 mm coil width) configurations, running at 16 m/min. The U-shape automatic duct production line covers TDF, angle flange and drive cleat seam types. This is the right machine for the general school envelope — classrooms, library, gymnasium, theatre, administration, refectory dining area, OSHC space. Z275 galvanising minimum for coastal schools (Sydney, Brisbane, Perth, Adelaide, Hobart). 380V 3-phase 50Hz power, ISO 9001:2015 and CE certified. See the SBAL-V product page for full technical data.
• SBTF-1500 spiral tubeformer for round duct. Spiral round duct is the preferred solution for multi-storey return risers (typical in two- and three-storey school buildings), atrium runs in independent school senior building feature spaces, and HEPA-filtered branches where pressure performance matters. Spiral round provides better pressure performance than rectangular at equivalent face velocity.
• SBSF-1525 stainless duct forming machine. Stainless steel 304 forming for chemistry lab fume hood plenum, biology autoclave extract, sick bay isolation room exhaust and the commercial kitchen exhaust envelope. The SBSF-1525 handles 1525 mm coil width stainless. Welded TIG seams for grease and corrosion integrity.
• SB-ZF1500 automatic stitchwelder. For stainless fume hood plenum welded seams, kitchen make-up air duct welded seams, and any application requiring fully automated longitudinal stitch welding for duct components up to 1500 mm in length. Handles material thickness from 0.8 to 3 mm with diameters from 150 to 1500 mm. Ideal for high-volume school project fume hood plenum and stainless kitchen exhaust fabrication.
• SBPC1500 plasma cutter for fitting fabrication. Fittings (elbows, branches, transitions) for the school project run through the plasma cutter for accurate cuts to AS 4254.2 tolerances. Where the project pipeline supports it, a CNC plasma cutter linked to BIM models reduces fitting fabrication time significantly.
• SBLR-600 elbow welder. Stainless segmented elbows for chemistry exhaust, kitchen exhaust and any other welded-seam application. The SBLR-600 handles 600 mm elbow segments with consistent weld penetration.
• SBFB-1500 spiral for multi-storey return riser. Where the school has a vertical return riser between floors, the spiral forming machine produces large-diameter spiral round duct for the riser. Round geometry handles the vertical airflow better acoustically than rectangular and survives differential thermal expansion between floors better.
• Spark-resistant construction for LPG bottle storage. Where the school canteen uses LPG bottles rather than mains natural gas, the bottle storage cabinet ventilation requires spark-resistant construction with conductive fasteners and grounded duct to manage static discharge per AS/NZS 60079 hazardous area classification.

A typical K-12 fabricator package occupies approximately 30 to 40 m of factory floor and supports two to three school projects per quarter at single-shift operation. For mechanical contractors with sustained school sector work — the panel contractors for Schools Infrastructure NSW, the Victorian School Building Authority, the Catholic Education Office of Sydney, or one of the major independent school groups — the capital payback against outsourced ductwork is typically 18 to 30 months.

See the comparison guide SBAL-V vs SBAL-III for the specification differences between the two auto duct lines.

Public school operators — state Departments of Education

The Australian public school sector is operated by the state Departments of Education, with each state running its own school infrastructure program through a dedicated agency. The largest operators (approximate 2026 school counts):

• NSW Department of Education — 3,000+ public schools, infrastructure delivered through Schools Infrastructure NSW. Mechanical specifications follow the NSW Department of Education Mechanical Services Standard.
• Victorian Department of Education and Training — 1,500+ public schools plus ~600 funded kindergartens, infrastructure delivered through the Victorian School Building Authority (VSBA). VSBA technical specifications mandate post-COVID CO2 monitoring.
• Queensland Department of Education — 1,200+ public schools, delivered through QLD Building and Asset Services.
• Western Australia Department of Education — 800+ public schools, delivered through Building Management and Works WA. Climate-adapted design for Perth metro, South-West and Pilbara/Kimberley remote schools.
• South Australia Department for Education — 700+ public schools.
• ACT Education Directorate — 90+ public schools with continued investment in Molonglo Valley.
• Northern Territory Department of Education — 150+ schools with tropical Darwin/Top End and arid Alice Springs climates.
• Tasmania Department for Education, Children and Young People — 250+ public schools.

Common state Department mechanical specification positions are AS 1668.2 ventilation, AS 4254 ductwork, AS 2107 acoustics, NCC Class 9b building classification, MERV 13 filtration minimum, post-COVID CO2 monitoring, NABERS Energy for Schools target rating, school holiday setback and AS 1428.1 accessibility. State-specific variations include AHU type (VAV with reheat in cool-temperate, displacement ventilation in warm-temperate and tropical), BMS interfacing, R32 refrigerant standard, and panel contractor procurement.

Catholic systemic schools — diocesan school networks

The Catholic systemic school network operates around 1,750 schools across Australia, organised by archdiocese and diocese. Each archdiocese maintains a Catholic Education Office that publishes facility specifications and runs the capital works program. The largest Catholic school operators are Sydney Catholic Schools (~170 schools, Catholic Schools NSW provides cross-diocese support), Melbourne Archdiocese Catholic Schools (~290 schools — largest single Catholic system in Australia), Brisbane Catholic Education (~145 schools), Catholic Education WA (~165 schools), Catholic Education SA (~105 schools), Catholic Education Tasmania (~40 schools), Catholic Education Canberra Goulburn (~55 schools) and Northern Territory Catholic Schools (~18 schools). Additional dioceses include Wollongong, Parramatta, Maitland-Newcastle, Bathurst, Lismore, Armidale, Wagga Wagga and Broken Bay in NSW, Sandhurst, Ballarat and Sale in Victoria, and Toowoomba, Townsville, Rockhampton and Cairns in Queensland. The Council of Catholic School Parents is the parent representation body across the network.

Catholic systemic school mechanical specifications generally follow the state Department of Education technical positions with diocesan additions — chapel ventilation (most Catholic schools include a chapel), religious education classrooms (no unusual HVAC requirements), and statue-friendly humidity controls in spaces hosting historical religious art or relics. Catholic schools commonly integrate the parish church into the school precinct — refer to the religious place of worship HVAC duct guide for the chapel and church HVAC pattern.

Independent schools — the bespoke specification market

The Australian independent school sector includes around 1,170 schools enrolling about 17 percent of all Australian students. The peak body is the Independent Schools Council of Australia (ISCA), with state associations AISNSW (400+ schools), Independent Schools Victoria ISV (200+ schools), Independent Schools Queensland ISQ, AISWA, AISSA, AISACT and AISTAS, plus the Australian Council of Heads of Independent Schools (ACHEDC). The major schools — those that historically supplied the leadership cohort of Australian business, law and academia and today operate substantial capital works programs:

• Victoria. Geelong Grammar (Corio), The Geelong College, Melbourne Grammar (East Melbourne), Scotch College Melbourne (Hawthorn), Wesley College Melbourne (Glen Waverley, St Kilda Road, Elsternwick), MLC Melbourne (Hawthorn), Trinity Grammar (Kew), Carey Baptist Grammar, St Catherine's School Toorak, Korowa Anglican, Camberwell Grammar, Caulfield Grammar, Haileybury (Keysborough, Brighton, Berwick, Castlefield, Melbourne, Newport).
• NSW. The King's School (Parramatta), Knox Grammar (Wahroonga), Sydney Grammar, Newington College, Cranbrook, Trinity Grammar Summer Hill, Shore (North Sydney), St Catherine's School Waverley, PLC Sydney (Croydon), The Scots College (Bellevue Hill).
• Queensland. Brisbane Grammar, Anglican Church Grammar (Churchie), Brisbane Boys' College, Brisbane Girls Grammar, Somerville House.
• Western Australia. Christ Church Grammar, Wesley College Perth, Scotch College Perth, Hale School, MLC Perth, Penrhos College.
• South Australia. St Peter's College Adelaide, Wesley College Adelaide, Pulteney Grammar, Prince Alfred College, Scotch College Adelaide.
• Tasmania. The Hutchins School (Sandy Bay), The Friends' School Hobart.
• ACT. Canberra Grammar, Daramalan College.

Independent schools operate bespoke mechanical specifications written by the school's consulting engineer, typically referencing the same Australian Standards as the public sector but with school-specific additions — heritage building constraints (many schools occupy buildings from the 1860s onward, requiring sensitive HVAC retrofit routing), Climate Active and 5.5- to 6-star NABERS Energy pursuit as parent-marketing differentiators, bespoke STEM precincts and senior school buildings (Wesley Melbourne's STEM Centre, Scotch Melbourne's Senior School redevelopment, Geelong Grammar's senior buildings), boarding house provision in most regional and many metro schools, dedicated 200- to 500-seat performing arts auditoria for the drama and music programs, and indoor swimming pools at the larger sites (see indoor pool and aquatic centre HVAC duct guide for the pool pattern).

EPC firms, consulting engineers and industry bodies

The Australian K-12 school capital works market is served by EPC firms and consulting engineers with sustained school-sector expertise — AECOM Australia, Aurecon, Norman Disney & Young (NDY), WSP Australia, Arup, Slattery Australia (cost management), and on the delivery side Schools Infrastructure NSW, the Victorian School Building Authority (VSBA), Lendlease, Built and Hutchinson Builders for PPP school packages, Capella Capital for PPP financing, and Cardno and Stantec for engineering consultancy. For modular and relocatable classroom delivery — increasingly common for capacity-expansion and remote school replacements — the major manufacturers include Anchor Buildings (Pinkenba QLD), Modular Building Solutions, Hutchinson Modular, McGrath Built Smart, Easy Move Cabins and Ausco Modular. Modular classrooms ship with prefabricated HVAC and require factory-tested duct connections, well suited to a fabricator running an SBKJ duct line in standardised module sizes.

Industry bodies and sustainability programs shaping the specification context include the Independent Schools Council of Australia (ISCA) as national independent peak body, the Australian Sustainable Schools Initiative (AuSSI), the Australian Education Union (AEU) with sustained focus on classroom indoor air quality, the Australian Council for Educational Research (ACER), NABERS Energy for Schools as the energy benchmarking tool, Climate Active for carbon neutral certification, Green Star Education for building rating, and Safe Work Australia Workplace Exposure Standards. The Safe Work Australia WES that drives the chemistry lab, kitchen and workshop HVAC are: CO2 5,000 ppm TWA (classroom IAQ target below 1,000 ppm), formaldehyde 1 ppm STEL, VOC general, ammonia 25 ppm, respirable dust 10 mg/m³, methylene chloride 50 ppm (rare in schools), iodine vapour, ozone 0.1 ppm (laser printer rooms), CH4 1.25 percent LEL (gas detection trigger), R32 refrigerant (split AC) and CO 30 ppm (gas kitchen).

Commissioning and the school facility manager's evidence pack

Commissioning is not complete when the AHU runs and the rooms hold setpoint. The handover deliverable is an evidence pack that survives Department of Education audit, the post-COVID Indoor Air Quality audit and the annual essential safety measures inspection: design intent statement; calculated and measured airflow schedules room-by-room with AS 1668.2 reference; AHU performance test record (coil, fan curves, motor draw, filter pressure drop, economiser verification); direct outdoor air measurement at each AHU intake (calculated values from damper position are no longer accepted by most state Departments); pressure relationship record (verified negative in chemistry labs, isolation rooms, kitchens and toilet blocks); acoustic measurement report against AS 2107 targets; AS/NZS 2243.8 fume cupboard face velocity verification with hot-wire anemometer at multiple sash positions; fire and smoke damper installation and AS 1851 drop-test certificates; CO2 sensor calibration record; filter change-out schedule for MERV 13 (annual) and HEPA H13 (twice-yearly) replacement; maintenance manual for the school facility manager; BMS training certificate including post-COVID CO2 dashboard interpretation; pre-occupancy purge log; and a 12-month measured NABERS Energy for Schools rating baseline after first full school year.

Ongoing operational verification

Ongoing verification is part of the service model — quarterly AHU service (coil clean, filter inspection, belt and coupling inspection, control valve stroke test, drain pan clean); annual ductwork inspection (internal condition, joint integrity, acoustic lining condition, damper position); annual filter replacement (MERV 13 annual, HEPA H13 twice yearly, pressure-drop logging as objective trigger); annual AS 1851 fire damper drop test; annual AS/NZS 2243.8 fume cupboard face velocity test with hot-wire anemometer at the design sash height; annual NDIR CO2 sensor calibration against reference; biennial duct cleaning with NADCA-style protocols and before-and-after documentation; continuous BMS monitoring of CO2, temperature, humidity, AHU status, filter pressure drop and damper position; and a pre-term purge schedule documented before each of the four school terms. Many state Departments are now writing continuous monitoring requirements into the consultant brief with data accessible to the regional facilities team via a cloud BMS.

Where this fits in the broader SBKJ insights library

This guide is part of the SBKJ insights library covering Australian institutional HVAC sectors. Closely related guides: the broader education, school and university HVAC duct guide covering the full educational pipeline; the tertiary university and TAFE workshop and engineering lab guide for university workshops, fume cupboard teaching labs and research labs; the under-5 childcare, kindergarten and OSHC guide for the regulated childcare sector under the National Quality Framework; the library, museum and archive guide for archive and special collection rooms; the cinema, theatre and entertainment guide for the school theatre pattern; the sports and fitness centre guide for the gymnasium and sports hall pattern at scale; the commercial kitchen exhaust guide for the canteen, refectory and boarding dining hall; the indoor pool and aquatic centre guide for schools with indoor pools; the hospital and healthcare guide for sick bay isolation rooms; the religious place of worship guide for chapels; the hotel and hospitality guide for boarding dormitories; the acoustic HVAC duct lining and attenuator guide; the SBAL-V vs SBAL-III machine comparison; the SBKJ machine catalogue; and the SBAL-V product page.

How SBKJ supports K-12 school projects

SBKJ Group's Australian operation is headquartered in Box Hill North, Victoria. Mechanical contractors fitting out K-12 school projects across Australia work with us on three workstreams:

• Duct line specification and supply. SBAL-V galvanised standard configuration with the options described above — Z275 galvanising for coastal schools, TDF flanges, acoustic lining capability, MERV 13-appropriate face velocities, plus the stainless 304 and spiral round equipment for the science and kitchen exhaust envelopes.
• Engineering review. Review of the consultant's mechanical specification against AS 1668.2, AS 4254, AS 2107, AS 2243, the NCC, the state Department of Education technical specification and the diocesan or independent school facility brief. Free for shortlisted projects.
• Commissioning support. Pre-handover review of the commissioning evidence pack, with sample reports from comparable school projects for benchmarking.

Talk to an SBKJ engineer about your K-12 school project →

FAQ

What outdoor air rate does AS 1668.2 require for an Australian K-12 classroom?

AS 1668.2 Table 3.2 sets 10 L/s/person for general classrooms. Post-COVID conservative practice raises this to 12 to 15 L/s/person with demand-controlled ventilation tied to CO2 monitoring. ASHRAE 62.1 is the international cross-reference; design to the greater of the two rates.

Is CO2 monitoring mandatory in Australian schools post-COVID?

CO2 monitoring is now required or strongly recommended in every Australian state and territory. Victorian DET distributed 51,000+ CO2 monitors to public schools. NSW DoE, QLD DoE and the ACT Education Directorate run similar programs. Trigger at 1,200 ppm, target below 1,000 ppm, aspirational below 800 ppm in primary classrooms.

What fume hood face velocity is required for a school chemistry lab?

AS/NZS 2243.8 requires 0.5 m/s ± 0.1 m/s at the design sash height for any fume cupboard. Most school specifications go nominal 0.5 m/s with a low alarm at 0.4 m/s and a continuous-monitor LCD display visible to the teacher.

What classification is a K-12 school under the NCC?

K-12 teaching buildings are classified Class 9b assembly, with Class 6 layered for any commercial kitchen, Class 9a for any sick bay with treatment beds, Class 9c for boarding house residential and Class 10b for groundskeeper storage. Class 9b drives mechanical ventilation to AS 1668.2, fire compartmentation and accessibility to AS 1428.1.

What acoustic NC target applies to school classrooms and theatres?

AS/NZS 2107:2016 sets NC-30 to NC-35 for classrooms, NC-30 for libraries, NC-25 to NC-30 for theatres and music rooms, NC-25 for recording studios, NC-35 to NC-40 for school halls and gymnasiums in active use.

What SBKJ machine line is recommended for a K-12 school fabricator?

SBAL-V galvanised auto duct line (SBAL-V-1250J or SBAL-V-1500J, 0.5 to 1.5 mm, 16 m/min) for the general school envelope, SBSF-1525 stainless for chemistry and kitchen, SB-ZF1500 stitchwelder for fume hood plenum, SBTF-1500 spiral for multi-storey return risers, SBPC1500 plasma for fittings, SBLR-600 elbow welder for stainless elbows.

How does the science lab differ from a general classroom?

Chemistry teaching lab: 8 to 10 ACH, 100 percent outside air, AS/NZS 2243.8 fume cupboards at 0.5 m/s, dedicated stainless exhaust to roof, AS 1940 chemical storage, negative pressure relative to corridor. Biology lab: PC1 (some senior labs PC2), small autoclave, BSC Class II Type A2 for genetic engineering. Physics lab: closer to general classroom plus local extract for laser cutting demonstrations and 3D printer ABS fumes.

Who are the largest Australian K-12 school operators?

Public: NSW DoE (3,000+ schools), VIC DET (1,500+ schools), QLD DoE (1,200+), WA DoE (800+), SA DfE (700+), TAS DECYP (250+), NT DoE (150+), ACT ED (90+). Catholic: Melbourne Archdiocese Catholic Schools (largest single network), Sydney Catholic Schools, Brisbane Catholic Education, Catholic Education WA, Catholic Education SA, Catholic Education Tasmania, Catholic Education Canberra Goulburn. Independent: ISCA at peak, with major schools including Geelong Grammar, Melbourne Grammar, Scotch College Melbourne, Wesley, MLC, Haileybury, The King's School, Knox Grammar, Sydney Grammar, Brisbane Grammar, Hale School, Christ Church Grammar Perth, St Peter's College Adelaide, Hutchins, Canberra Grammar.