Why education HVAC is unique
Education facilities are unlike any other building type the HVAC industry serves. They combine the highest occupant density of any non-assembly occupancy, a brutally repetitive 8 AM to 3 PM CO2 ramp, three 10-week academic terms separated by holidays during which the building sits nearly empty, and a programme mix that nominally calls itself a single building but operationally covers a classroom block, a science wing, a gymnasium, a library, a cafeteria, an auditorium, an administration block and increasingly a swimming pool — each with its own acoustic, ventilation and energy requirements.
On top of all that, the budget per square metre is roughly half of a commercial office and a fraction of a hospital, and the user (a 12-year-old who cannot read a thermostat) cannot give the BMS feedback when the system is failing. The HVAC engineer is designing for an audience that physiologically struggles with high CO2 (cognitive performance drops measurably above 1,200 ppm in school-age children), generates roughly 60 percent of the moisture and odour load that adults do per kilogram body mass, and spends six to eight hours a day in the same room.
Fabrication and commissioning of school ductwork is also unlike commercial work. The site is occupied by minors, which means stricter contractor controls, mandatory working-with-children certification for installers, school holiday delivery windows that compress 12 weeks of work into a six-week January break or a two-week mid-year break, and an asset owner (state education department, diocese, university facilities team) who will run the building for 40 to 60 years rather than sell it on a 7-year cycle. Specification mistakes compound across decades of operation and tens of thousands of student-occupant hours per year.
This guide is the engineering reference SBKJ uses with school architects, mechanical consultants, head contractors and university campus planners across Australia, from greenfield K-12 campuses on the urban fringe of Sydney and Melbourne to retrofit projects in heritage-listed Group of Eight university buildings. It walks the full duct specification — facility type, occupancy density, ASHRAE and Australian Standards ventilation rates, classroom acoustic NC, lecture theatre and library treatment, science lab fume hood exhaust, gymnasium and cafeteria, materials, fabrication tolerances, NABERS Energy targets, school holiday setback, and the SBKJ machinery stack that produces the duct package on time and to leakage class.
The Australian education facility typology
Before specifying any HVAC, the engineer needs to nail down which education facility type the project is. Each type has a different occupancy density, schedule and seasonal swing that drives ventilation sizing.
Primary school (P-6)
A primary school in Australia covers Foundation (Prep, sometimes Kindergarten) through Year 6. Typical enrolment is 200 to 600 students across 8 to 24 home-room classrooms of 22 to 28 students each. Occupancy density is around 1.8 to 2.0 m² per student (lower than secondary because the body is smaller and the room layout is more flexible). The schedule is concentrated 9 AM to 3 PM with morning recess and lunch break, and the seasonal swing is the standard four-term Australian academic calendar with the long break in December–January.
Primary classrooms typically use ducted reverse-cycle split systems or VRV/VRF zoned to two or four classrooms per indoor unit, with mechanical fresh-air supply through a separate duct path. Acoustic target is NC-30 to NC-35. Materials are standard galvanised duct with internal acoustic lining over the last 6 to 9 m of supply branch.
Secondary school (Years 7-12)
Secondary schools cover Years 7 to 12 in most Australian states (Year 7 to 11 in some independent schools, Year 7 to 13 in a small number of international curriculum schools). Enrolment ranges from 600 to 2,000 students. Occupancy density is 2.0 to 2.4 m² per student, slightly higher than primary because the room layout includes individual desks and laboratory benches. The programme mix is more diverse: general classrooms, science laboratories (chemistry, biology, physics), home economics and food technology rooms, woodwork and metalwork shops (with their own dust and fume extraction), art studios with kiln rooms, music rooms with isolation requirements, gymnasium, cafeteria, library, auditorium and administration block.
The HVAC architecture for a secondary school is more zoned than a primary school. Each programme area is typically a separate AHU or rooftop unit with appropriate filtration, acoustic treatment and exhaust integration. The duct package is roughly 2.5 to 3 times the linear metre count of a primary school of equivalent enrolment, simply because of the programme diversity.
Combined K-12
K-12 schools combine primary and secondary on a single campus, common in independent and Catholic education and increasingly in regional state schools where population is too small to support separate campuses. Enrolment 800 to 2,500. The HVAC challenge is interface zoning: the primary block needs to be acoustically and operationally separate from the secondary block (different bell schedules, different recess times) but share the same central plant economically.
TAFE, vocational and Registered Training Organisation (RTO)
TAFE and RTO facilities deliver vocational education across trades and tertiary qualifications. The programme mix is industrial: welding workshops, automotive workshops, hairdressing and barbering training salons, commercial cookery training kitchens, beauty therapy rooms, allied health simulation labs, IT and electrical training rooms. The HVAC architecture is dominated by exhaust integration — welding fume extraction, automotive bay extraction, kitchen exhaust, hair salon chemical extraction, nail salon dust extraction. Galvanised duct is supplemented with stainless steel and PVC depending on the chemical environment.
University campus
Australian university campuses fall into several tiers. The Group of Eight (Sydney, Melbourne, ANU, UQ, Monash, UNSW, Adelaide, UWA) operate research-intensive campuses with high lecture theatre density, large libraries, extensive science and engineering laboratories, indoor sports centres, residential colleges and increasingly co-located medical research institutes. Technology universities (UTS, RMIT, Curtin, QUT, Deakin, Macquarie, Western Sydney, Swinburne) have a similar programme mix with stronger applied-research and teaching-lab focus. Regional universities (Newcastle, Wollongong, James Cook, Charles Sturt, Southern Cross, Federation, Charles Darwin, La Trobe regional campuses) often combine teaching and limited research on smaller campus footprints.
University HVAC is the most complex education facility type. A single building can include 500-seat lecture theatres, 50-seat tutorial rooms, undergraduate teaching labs, postgraduate research labs, academic offices, a library wing, a cafe and a small auditorium. Each occupancy has different ventilation, acoustic, schedule and energy targets, and the building serves a 24/7 academic community rather than a 9-to-3 school day.
Research institute
Australia hosts a strong network of research institutes co-located with universities and independently. CSIRO operates national research facilities at multiple sites. Defence Science and Technology Group runs classified labs at Edinburgh SA, Fishermans Bend VIC and other locations. ANSTO operates the Lucas Heights nuclear and synchrotron facilities. Medical research institutes including Walter and Eliza Hall (Parkville VIC), Garvan Institute (Darlinghurst NSW), Centenary Institute (Camperdown NSW), QIMR Berghofer (Herston QLD), Telethon Kids Institute (Nedlands WA), Menzies (Hobart TAS) and the Florey Neuroscience Institute (Parkville VIC) run cleanroom and BSL-2/BSL-3 laboratory environments.
Research institute HVAC is closer to pharma cleanroom than to school HVAC. Refer to the SBKJ cleanroom industry page and the pharma and biotech cleanroom guide for full specification of these environments. Within an education-focused building (a teaching wing of a research institute), the HVAC reverts to standard university lecture and lab specification.
Early childhood centre and kindergarten
Early childhood education and care covers long day care, kindergarten and pre-school for children aged six weeks to five years. Occupancy density is the highest of any education facility — 1.5 to 1.8 m² per child including cot rooms. Per-person ventilation rates are slightly higher than primary classroom because children's tidal volume per kilogram body mass is higher. Acoustic target NC-30 with significant attention to low-frequency rumble that can wake sleeping infants. Materials are typically standard galvanised with anti-microbial internal lining.
Language school and religious school
Language schools (English Language Intensive Courses for Overseas Students, ELICOS) and religious schools serve specific student populations with shorter schedules or different programme structures. HVAC architecture is essentially the same as primary or secondary depending on the age range, with attention to multi-cultural building usage patterns (extended hours, weekend operation for religious schools).
Online learning hub
A relatively new building type, online learning hubs are physical centres for predominantly remote students to access supervised exam sessions, group tutorials and IT resources. Lower occupancy density than a traditional classroom (one PC per student, typically 4 m² per workstation) but high IT cooling load. Acoustic target NC-30 to NC-35, high-grade filtration to manage particulate from student commute, and zoned VAV with individual workstation control where budget allows.
Australian education capital programme context
SBKJ machinery is specified into Australian education projects through several major capital programmes worth combined tens of billions of dollars over rolling five-year horizons.
State public school capital programmes
NSW School Infrastructure manages the largest public school capital pipeline in Australia at over USD 8 billion across new schools, major upgrades, and the Cooler Classrooms programme that is air-conditioning state schools across the state. Procurement is centralised through Department of Education with mechanical specification typically aligned to NCC Section J, AS 1668.2 and a target NABERS Energy for Schools rating of 5 stars or higher.
VIC School Building Authority (operating under the Victorian Department of Education) runs over USD 2 billion of annual school capital. The Permanent Modular Schools programme, the Greater Shepparton Secondary College replacement, the new schools rolled out across Melbourne's growth corridors (Wyndham, Whittlesea, Casey) and the upgrade of Inner Melbourne Secondary College all follow this funding pipeline. NABERS Energy for Schools targets are 5 stars minimum on new builds.
Queensland Department of Education coordinates the Building Future Schools programme including new high schools across Brisbane, Gold Coast, Sunshine Coast, Toowoomba and the regional centres. Tropical climate ventilation requirements push higher fresh-air rates than southern states and demand stricter humidity control on the supply path.
Western Australian Department of Education runs new school construction across the Perth metro growth corridors and regional WA. SA Department for Education, Tasmanian Department for Education, NT Department of Education and ACT Education Directorate run smaller but proportionally similar capital pipelines.
Private and Catholic school capital expenditure
The Greater Public Schools (GPS), Associated Public Schools (APS) and equivalent independent school networks across Australia collectively run school capital programmes in the hundreds of millions per year. Catholic Education in each diocese (Sydney, Melbourne, Brisbane, Adelaide, Perth and the regional dioceses) operates its own capital pipeline. Private schools typically specify higher acoustic targets and more sophisticated HVAC architecture than state schools because of the parent-funded fee base.
Australian university capital expenditure
The Group of Eight universities collectively run over USD 3 billion of annual capital programme covering new teaching buildings, research facilities, student accommodation and major refurbishment of heritage-listed campus buildings. Sydney University has the Charles Perkins Centre, Susan Wakil Health Building and ongoing camperdown campus master plan. The University of Melbourne has the Parkville campus master plan including the Western Edge Biosciences building and the Student Precinct. ANU has Acton campus redevelopment. Monash has the Clayton campus expansion. UNSW has Kensington campus master plan. UQ has St Lucia campus expansion. Adelaide and UWA each operate similar pipelines on their respective campuses.
Technology universities (UTS Broadway, RMIT Swanston, Curtin Bentley, QUT Gardens Point, Deakin Burwood and Geelong, Macquarie North Ryde) and regional universities together represent another USD 1.5 billion of annual capital. Each pipeline includes lecture theatres, libraries, lab buildings, admin and student-services buildings, all of which need substantial HVAC duct fabrication.
Research institute capital
Research institute capital spend is typically smaller in dollar terms but requires the most demanding HVAC specification. CSIRO, Defence Science and Technology Group, ANSTO and the medical research institutes (Walter and Eliza Hall, Garvan, Centenary, QIMR Berghofer, Telethon Kids, Menzies, Florey) all run rolling capital programmes for new lab buildings and major lab refurbishments. Specification typically references AS 2243 (laboratory safety), AS/NZS 2982 (laboratory construction), and the relevant biosafety standards (AS/NZS 2243.3 Microbiological safety).
Key standards and references
Australian education HVAC design references several Australian and international standards. The mechanical engineer typically designs to whichever produces the higher fresh-air rate or stricter acoustic target.
Ventilation and indoor air quality
ASHRAE 62.1 — Ventilation for Acceptable Indoor Air Quality. Table 6-1 gives default occupant and area ventilation rates by occupancy category. For classrooms ages 9 and above, the rate is 5 cfm per person plus 0.06 cfm per square foot of floor area. For ages 5-8 the rate increases to 7.5 cfm per person plus 0.06 cfm per square foot, and for ages 4 and under it is 10 cfm per person plus 0.18 cfm per square foot. Lecture theatres are 7.5 cfm per person, libraries are 5 cfm per person plus 0.12 cfm per square foot, science labs are 10 cfm per person plus 0.18 cfm per square foot, and gymnasiums are 20 cfm per person.
ASHRAE 170 — Ventilation of Health Care Facilities. Applied where the school includes a medical clinic (boarding school sick bay, university student health centre, on-campus medical centre). Specifies pressure cascades, air change rates and filtration that exceed the standard education category.
AS 1668.2 — The use of ventilation and airconditioning in buildings: Mechanical ventilation in buildings. The Australian Standard for mechanical ventilation. Table 3.2 gives minimum outdoor air rates by occupancy: 10 L/s per person for general classrooms and offices, 12 L/s per person for libraries and laboratory rooms, 12 L/s per person for science labs, 15 L/s per person for assembly halls, 25 L/s per person for gymnasiums during PE, and specific rates for kitchens (50 L/s per square metre of cooking surface).
For most Australian education projects, AS 1668.2 produces a slightly higher fresh-air rate than ASHRAE 62.1 and therefore governs the design. For projects with a strong international standard reference (some independent schools, multi-national university partnerships), ASHRAE 62.1 is run in parallel and the higher value used.
Energy efficiency
National Construction Code (NCC) Section J — Energy efficiency. Sets minimum energy performance for class 9b (assembly buildings, including schools) and class 5/6 (university teaching buildings). HVAC-specific clauses cover minimum equipment efficiency, economiser cycle, fan power, duct insulation, and building automation. Section J 6 is the verification pathway for HVAC specifically.
NABERS Energy for Schools. The Australian National Built Environment Rating System operates a school-specific tool that measures whole-school energy use intensity in MJ per square metre per year against a benchmark database. Star ratings range from 0.5 to 6 stars in 0.5-star increments. New school designs increasingly target 5 stars or higher, which requires aggressive HVAC efficiency including demand-controlled ventilation, deep school holiday setback, full economiser, low static pressure design and tight-leakage ductwork.
Green Star — Education v1 / v2. The Green Building Council of Australia operates a Green Star tool for education buildings covering energy, water, materials, indoor environment, transport, land use and innovation. HVAC contributes to energy and indoor environment credits.
Acoustic standards
AS/NZS 2107:2016 — Acoustics: Recommended design sound levels and reverberation times for building interiors. Table 1 gives recommended internal noise levels: NC-30 to NC-35 for primary and secondary classrooms, NC-25 to NC-30 for university lecture theatres, NC-25 to NC-30 for music rooms, NC-30 for libraries with study areas, NC-35 to NC-40 for gymnasiums and indoor sports halls, NC-25 for theatres and drama studios.
Refer to the SBKJ acoustic HVAC duct lining and attenuator guide for the full duct treatment specification at each NC target.
Smoke management and life safety
AS 1668.4 — Smoke management. Required for assembly occupancies including lecture theatres, auditoriums and gymnasiums. Specifies smoke exhaust fan capacity, smoke duct fire rating and zoning for safe egress.
NFPA 92 — Standard for Smoke Control Systems. Often referenced alongside AS 1668.4 for university lecture theatres and auditoriums to international standards.
Classroom HVAC architecture
The general classroom is the building block of every school. Get the classroom right and you have got 70 percent of a primary school, 60 percent of a secondary school and 40 percent of a university by linear metre of duct. Get it wrong and the project ships with student health complaints, parent emails and uncomfortable Year 9 maths classes.
Zone definition
A typical Australian school AHU zone covers two to four classrooms, or 60 to 80 student-occupants. Larger zoning saves capital cost but reduces individual teacher control and increases temperature variance during partial occupancy. The trend over the past decade has been toward smaller zones (one or two classrooms per VAV box) with central AHU, supported by demand-controlled ventilation to maintain energy efficiency.
Air distribution strategy
Two main strategies are used in Australian classrooms. Mixing ventilation uses ceiling-mounted supply diffusers with high-induction throw, mixing the supply air with room air to deliver a uniform temperature and CO2 concentration. This is the conventional approach and remains dominant in retrofit and budget-constrained new builds.
Displacement ventilation supplies cool, low-velocity air at floor level (perimeter sidewall or column-mounted diffusers) and removes warm exhaled air at the ceiling. Because supply air is cooler and at the breathing zone before it mixes with room air, displacement ventilation delivers measurably lower CO2 at the student's breathing height for the same total airflow. It is increasingly specified in new Australian schools and is mandatory in some state department guidelines for primary classrooms.
Displacement ventilation classrooms typically use 25 mm internal acoustic lining over the last 6 to 9 m of supply branch (lower than mixing because face velocity is lower) and supply diffuser face velocity under 1.5 m/s. The duct material is standard galvanised G90 with smooth internal lining for low pressure drop.
VAV terminal control
Each classroom typically has a VAV terminal (variable air volume box) with a damper and reheat coil controlled by the BMS. Occupant temperature setpoint adjustment is via a wall thermostat with a limited setpoint band (typically 21 to 24 °C in winter and summer respectively). The VAV box modulates supply airflow between minimum (typically 25 to 35 percent of design flow for ventilation only) and maximum (100 percent of design flow for peak cooling).
Demand-controlled ventilation
CO2 sensors are wall-mounted at 1.2 to 1.5 m above the floor, away from supply diffusers and exterior walls. Sensor type is NDIR (non-dispersive infrared) for accuracy and stability over a 5 to 7 year sensor life. The BMS modulates the outside air damper at the AHU and/or the VAV box minimum setpoint to maintain CO2 below the setpoint (1,000 ppm typical, 800 ppm for primary classrooms in some progressive specifications).
Post-COVID, many state education departments now require continuous CO2 logging with parent or staff visibility through the BMS. NSW Department of Education in particular has rolled out CO2 monitoring across thousands of classrooms with public-facing dashboards.
University lecture theatre HVAC
University lecture theatres are the highest occupancy density educational space — fixed seating typically delivers 0.6 m² per person. A 200 to 500 seat theatre is essentially an assembly occupancy with academic timetabling, switching from full to empty in three minutes between hour-long lectures.
Dedicated AHU and displacement ventilation
Lecture theatres almost universally use a dedicated AHU sized for full peak occupancy with displacement ventilation under raked seating. Supply diffusers are typically integrated under each seat or in the riser face below the seat row, with low face velocity (under 1.5 m/s) and supply air temperature 17 to 19 °C (cooler than mixing supply because the air is delivered directly to the breathing zone with minimal mixing).
Acoustic target NC-25 to NC-30
Lecture theatre audio quality requires NC-25 to NC-30 ambient noise. This is achieved through low-velocity supply air, large volume duct with 50 mm internal acoustic lining over the supply branch, an inline attenuator at the AHU discharge and a return-air attenuator at the AHU intake. Total attenuation across the supply path typically delivers 25 to 35 dB of noise reduction across the 250 Hz to 4 kHz speech band.
Smoke management
Lecture theatres above 100 occupants are typically smoke-managed under AS 1668.4 and NFPA 92, with smoke exhaust fans sized for 4 air changes per hour in the upper smoke zone, smoke-rated dampers at every penetration, and a dedicated smoke control panel integrated with the fire alarm system. Smoke duct is typically 1.5 mm galvanised with welded longitudinal seams or 1.0 mm with lock-formed seams sealed with intumescent gasket.
Free cooling and economiser
Lecture theatres with peak cooling load 50 to 150 kW benefit substantially from full economiser cycle. When outside air temperature is below return air temperature (very common in Australian winter and shoulder seasons even with internal occupancy load), the AHU runs 100 percent outside air and bypasses the cooling coil, saving compressor energy. This is a major NABERS Energy contributor for university buildings.
Library HVAC
Libraries are deceptively complex. The book stack mass is a thermal flywheel storing daytime heat into the evening. Lighting is typically high (350 to 500 lux at the reading table). IT equipment in computer rooms and learning commons adds a sensible load. And the acoustic target is NC-30 across reading rooms and study spaces.
Zoning
A typical university library has at least three HVAC zones: reading and study rooms (NC-30, normal occupancy schedule), the open stack collection (NC-35, lower fresh-air rate per AS 1668.2 because lower occupancy density), and special collection or archive rooms with tight humidity control.
Archive and special collection HVAC
Special collection rooms holding rare books, manuscripts, photographic archives or research records require dedicated HVAC with humidity control 45 to 55 percent RH, temperature 18 to 22 °C, and tight filtration (MERV 13 minimum, MERV 14-15 for sensitive collections). Materials in the duct path should not off-gas formaldehyde or VOCs that could damage paper. Internal lining is typically smooth aluminium-faced fibreglass rather than raw fibreglass.
Science laboratory HVAC
School and university science laboratories combine a teaching space with a chemical environment. Specification is dominated by exhaust integration: fume hoods, biosafety cabinets, snorkel exhaust, gas cabinet exhaust, and general lab dilution exhaust. The supply path is also more demanding because it must make up the exhaust flow without short-circuiting.
Chemistry laboratory
A typical secondary or undergraduate chemistry lab has 4 to 8 fume hoods on the perimeter or in a central island layout. Each fume hood at fully open sash demands face velocity 0.5 m/s, which for a typical 1.5 m wide hood at 0.7 m sash opening produces an exhaust flow of 1.1 m³/s (3,800 m³/h or 2,200 cfm). For 6 hoods running simultaneously, the lab exhaust system is sized for around 6.5 m³/s.
Variable air volume fume hoods (VAV hoods) reduce energy by modulating exhaust based on sash position, but the supply system must still be sized for the maximum simultaneous diversity case (typically 60 to 75 percent simultaneous use at design). Material is 304L stainless steel with welded longitudinal seams, pickled and passivated. PVC or PP is used for trace acid systems (perchloric acid hoods specifically require PVC with a wash-down system).
Biology laboratory
Biology labs typically have biosafety cabinets (BSC Class II Type A2 or B2) for tissue culture and microbiology work. Class II Type A2 BSCs recirculate 70 percent of the air through HEPA filters and exhaust 30 percent to a thimble exhaust connected to the lab exhaust system. Class II Type B2 BSCs are 100 percent exhausted (hard-ducted) and require dedicated exhaust connection.
For higher containment (BSL-2+ research labs in undergraduate teaching, BSL-3 in research institutes), refer to the SBKJ cleanroom industry page and the pharma cleanroom guide.
Physics and electronics laboratory
Physics labs typically have lower exhaust requirements but may have laser safety zones, RF shielded rooms or vibration-isolated optics tables. HVAC architecture is essentially a higher-quality classroom with vibration isolation on the supply branch (flexible connectors, neoprene hangers, oversized duct with low velocity).
Radiation and gas room
Radiation labs (low-level radioisotope work in undergraduate teaching, research-grade radioisotope work at universities) require dedicated exhaust with HEPA filtration and zoned shutoff. Gas rooms storing flammable or toxic compressed gas require ATEX zoning and continuous extract in some cases. Material is 304L stainless welded for radiation, and PVC or stainless for gas room depending on the specific gas inventory.
Gymnasium and sports centre HVAC
School and university gymnasiums combine a high latent load (PE class body heat and moisture) with a high acoustic background (basketball games, PE class noise) and increasingly with secondary use as assembly hall for whole-school events. The HVAC architecture has to handle PE peak (25 L/s per person fresh air at peak occupancy) and assembly peak (500 to 2,000 occupants in a school gymnasium during a parent evening or graduation).
Displacement ventilation
Modern school gymnasiums use displacement ventilation from low sidewall diffusers, with high return at the ridge or roof penetrations. This handles the latent load (sweat evaporation) more effectively than overhead mixing because the warm moist air rises naturally to the return. Supply air temperature 18 to 20 °C, supply face velocity under 2.0 m/s.
Smoke management
Gymnasiums above 100 occupants when used as assembly are typically smoke-managed under AS 1668.4 / NFPA 92, with smoke exhaust at the ridge and make-up air at low level. Smoke ductwork is typically 1.0 to 1.5 mm galvanised with appropriate fire rating.
Acoustic target NC-35 to NC-40
Gymnasiums are tolerant of higher background noise, but the duct system should still achieve NC-35 to NC-40 to allow PE teacher voice command to carry across the floor and audio system intelligibility during assembly use.
Materials and fabric duct
Fabric ductwork is increasingly specified for gymnasium supply because it delivers very low face velocity (uniform porosity), is light, easy to clean (machine-washable in some products), and aesthetically acceptable in an exposed gym ceiling. Standard galvanised remains the workhorse for return air and smoke exhaust.
Cafeteria and canteen HVAC
School and university cafeterias combine three HVAC challenges: kitchen exhaust (high temperature grease-bearing), dishwasher humidity (high latent load), and dining occupant comfort (mixed-age students at peak lunch).
Kitchen exhaust
Commercial kitchen exhaust is specified to NFPA 96 / AS 1668.2 with hood capture velocity 0.5 m/s at hood face for canopy hoods and 0.4 m/s for proximity hoods. Exhaust ductwork is welded 304L stainless or 1.6 mm galvanised welded with appropriate fire-rated enclosure. Grease cleaning access is provided every 3 to 6 m of duct run.
Dishwasher hood
Commercial dishwashers produce significant latent heat that must be exhausted at the source. Dishwasher hoods are typically captive type (covering the dishwasher exit) with separate exhaust fan sized for moisture removal.
Dining area
The dining area itself is a normal occupancy zone — 24 °C supply, 50 percent RH, NC-35 acoustic target, fresh air per AS 1668.2 for dining. Diner density is typically 1.5 m² per occupant at peak service, dropping to 3 m² off peak.
Auditorium and drama studio HVAC
School and university auditoriums host whole-school events, drama productions, music recitals, public lectures and external community events. The HVAC architecture is theatre-grade: NC-25 acoustic target, displacement ventilation under raked seating, dedicated AHU with low static pressure (under 250 Pa external) to minimise fan noise.
Drama studios with rehearsal and recording use require the same NC-25 acoustic target with isolated supply and return paths to prevent cross-talk between adjacent rehearsal rooms. The dimmer-rack room (lighting control) requires separate HVAC with substantial heat rejection (lighting dimmers and rack-mounted equipment generate continuous heat even when the auditorium is empty).
Indoor pool HVAC (school pool)
Schools and universities increasingly include indoor swimming pools, particularly larger independent schools and university sports complexes. The HVAC architecture is dominated by dehumidification — the pool natatorium typically runs at 50 to 60 percent RH, and the dehumidification AHU is sized for the evaporation rate from the pool surface plus the deck wet area.
Refer to the SBKJ indoor pool and aquatic centre HVAC duct guide for full specification including 316 stainless or fabric duct material selection, condensation management, pool deck supply diffuser layout and isolation from main school HVAC.
Music room HVAC
Music rooms, recording studios and instrumental practice rooms require NC-25 acoustic target. The duct system must avoid cross-talk between adjacent practice rooms — a single trunk serving multiple rooms allows sound to travel through the duct from one room to the other ("flanking transmission" or "duct cross-talk"). Each music room typically has an isolated supply branch with 50 mm internal acoustic lining over the full branch length, an inline attenuator at the room boundary and a separate return path.
Recording studios with critical acoustics may require even tighter NC-20 targets, achieved through oversized duct (lower face velocity), full-length internal lining and a sound trap at the room boundary.
Special needs and disability access HVAC
Special needs classrooms, sensory rooms and autism spectrum learning environments require very low ambient noise (NC-25 typical), low air movement at occupant level (under 0.15 m/s), and individual zone control to allow temperature and ventilation adjustment for students with sensory sensitivities.
Linear slot diffusers (which can produce annoying high-frequency hiss at low flow) are typically avoided in favour of perforated face diffusers with very low face velocity. Internal acoustic lining is increased to 50 mm on the supply branch. The supply path includes vibration isolation to prevent low-frequency rumble that can trigger sensory distress.
Boarding house HVAC
Boarding schools and university residential colleges include guest-room style accommodation. HVAC architecture is closer to hotel guest room than classroom — fan coil units in each room, fresh air through a corridor or in-room ventilator, individual occupant control. Acoustic target NC-30 to NC-35 (sleep environment), supply face velocity under 2.5 m/s, internal acoustic lining over the supply branch.
Indoor air quality and student health
Post-COVID, the indoor air quality conversation in Australian education has shifted permanently. Where pre-2020 designs commonly used MERV 8 to 11 filtration, post-2022 the standard is MERV 13 minimum at the AHU, with MERV 14-15 specified for high-occupancy zones such as lecture theatres and assembly halls. The increased filter pressure drop must be designed into the fan static curve and AHU coil selection — retrofitting MERV 13 into a system designed for MERV 8 typically loses 20 percent of design airflow.
CO2 monitoring
CO2 monitoring has moved from "nice to have" to standard specification across Australian schools. NDIR sensors with calibration certificate, BMS integration, continuous logging and parent or staff visibility through the BMS dashboard are now baseline. NSW Department of Education has rolled out CO2 monitoring across thousands of classrooms with public-facing dashboards.
Particulate from outdoor pollution
Urban schools — particularly those in inner Sydney, inner Melbourne, inner Brisbane and the Adelaide CBD — are exposed to vehicle exhaust particulate, brake dust and re-entrained road dust. Higher-grade outside air filtration (MERV 13 minimum, F8 or higher in EN classification) is increasingly specified to manage this load. School playgrounds adjacent to major arterial roads have been a research focus and HVAC specification has responded.
Materials
Australian school and university duct fabrication uses a relatively narrow material palette compared with industrial HVAC, optimised for cost, fabrication speed, durability and the specific environment.
Galvanised steel G90 (AS 1397 Z275)
The workhorse of school HVAC. Galvanised steel to AS 1397 Z275 (G90 imperial equivalent) at 0.55 mm to 1.00 mm gauge depending on duct size, fabricated to AS/NZS 4254.2. Used for general supply and return in classrooms, offices, libraries, lecture theatres, gymnasium return air, cafeteria dining area supply. Service life 30 to 50 years in normal indoor environment.
Internally lined galvanised duct
Standard galvanised duct with 25 mm or 50 mm internal acoustic lining, used for classroom acoustic treatment, library supply, lecture theatre, music room and auditorium. Lining is typically fibreglass duct liner with neoprene-coated facing for surface durability.
Fabric ductwork
Increasingly common for retrofits, gymnasiums, large open zones and exposed-ceiling architecture. Fabric duct delivers uniform low-face-velocity supply through engineered porosity, is lightweight, machine-washable, and aesthetically acceptable. Used in school gyms, university atriums and learning commons.
304L stainless steel
Used for kitchen exhaust (NFPA 96 / AS 1668.2 grease-bearing exhaust) and chemistry lab fume hood exhaust. Welded longitudinal seams, pickled and passivated. Service life 30+ years in kitchen application, 20 to 30 years in chemistry application depending on chemical inventory.
PVC and PP
Used for trace acid exhaust (perchloric acid hoods specifically), chemistry storage room exhaust where chemical resistance is required, and some sciences lab installations where stainless is over-specified. Lower temperature limit and UV sensitivity must be considered.
316 stainless and fabric duct (pool)
For schools with indoor pools, the chlorinated air environment requires 316 stainless or fabric duct with corrosion-resistant coating. See indoor pool guide.
Fire-rated duct
Kitchen exhaust risers and smoke management duct require fire-rated assembly. Typically 1.6 mm galvanised with welded seams and Promatect or equivalent boarding to 2-hour fire rating per AS 1530.4.
Energy efficiency
Energy efficiency in school HVAC is dominated by five strategies that together can reduce annual energy use by 30 to 50 percent compared with code-minimum design.
Economiser cycle
Full air-side economiser allows the AHU to run 100 percent outside air whenever outside conditions are cooler than return air. In Australian climate (Sydney, Melbourne, Adelaide, Perth), economiser hours typically run 1,500 to 2,500 hours per year, eliminating compressor cooling energy during shoulder seasons and most winter daytime hours.
Demand-controlled ventilation
CO2-modulated outside air damper or VAV box minimum delivers the right amount of fresh air for actual occupancy rather than design occupancy. In a typical primary classroom that runs at 60 to 80 percent of design enrolment most days, DCV saves 20 to 30 percent of fresh-air energy.
Free cooling overnight
Where the building has thermal mass (concrete slab, exposed brick), overnight free cooling flushes the building with cool outside air and pre-cools the structure, reducing the morning cooling load. Implemented through scheduled outside air damper opening and supply fan operation 2 to 4 AM in summer.
Low static pressure design
Lower static pressure means lower fan power. Target external pressure for the AHU under 250 Pa, achieved through generous duct sizing (lower face velocity), fewer fittings per linear metre, large radius elbows (1.5 D or longer), and tight duct fabrication (minimal leakage adds artificial pressure drop). NABERS Energy modelling responds directly to fan static curve.
BMS scheduling and school holiday setback
Building automation system runs a school day schedule (cooling and ventilation 7 AM to 4 PM, weekday) with occupancy override for after-hours events. School holiday schedule runs deep setback: outside air at minimum, fans cycled off for unoccupied hours, supply temperature relaxed by 4 to 6 °C. Pre-occupancy purge two hours before first day of return-to-school flushes the building with fresh air.
School holiday HVAC operation
Australian schools typically have four academic terms with three holiday breaks plus the long summer break:
- Term 1 holidays: 2 weeks in April
- Term 2 holidays: 2 weeks in July (mid-year break)
- Term 3 holidays: 2 weeks in September-October
- Summer holidays: 6 to 8 weeks December-January
During school holidays, the building runs at minimum ventilation (closed outside air dampers, infiltration only), AHU fans cycled off for unoccupied hours (cleaning crews work 6 AM to 2 PM only), supply temperature relaxed to 26 °C cooling and 18 °C heating setpoints, no demand-controlled ventilation. The BMS schedule transition is a major energy saving — typical Australian school energy use during the 6-week summer break is 20 to 30 percent of school day operation.
The pre-occupancy purge is critical. Two hours before students arrive on the first day of return-to-school, the BMS runs full outside air at full supply fan to flush any accumulated indoor pollutants (off-gassing from new furnishings, cleaning chemical residue, settled dust). This pre-occupancy purge is now standard in Australian school BMS programming.
SBKJ machinery for education projects
Education projects typically run on tight programme deadlines aligned to school holiday installation windows. The duct fabrication shop has to deliver a large volume of standardised rectangular duct (classrooms, offices, library), a moderate volume of round duct (lecture theatres, atriums, gym supply), and a small but technically demanding stainless duct package (kitchen, chemistry lab). The SBKJ machinery stack supports this mix on a single factory floor.
SBAL-V Series VI auto duct production line
The SBAL-V auto duct production line is the workhorse for education project rectangular duct fabrication. In galvanised configuration with 1.0 mm maximum gauge and 1,500 mm coil width, it produces a typical school project's rectangular duct package in 6 to 10 weeks single-shift, or 4 to 6 weeks two-shift operation. Setup includes coil decoiler, leveller, notching station, lock-former (for Pittsburgh or button-punch lock), shear, TDF flange former (integrated or inline), and labelling for shop drawing identification.
Output specification: 60 to 85 m of finished rectangular duct per hour at typical school project mix (mix of 200 x 150 mm to 1,200 x 800 mm cross-sections), 0.55 to 1.00 mm gauge, length tolerance ±2 mm, squareness ±1 mm per linear metre, leakage class A or B per AS 4254.2.
SBTF spiral tubeformer for round duct
The SBTF spiral tubeformer in 1,500 mm diameter capacity produces the round duct package for lecture theatres, atriums, gym supply, and university ductwork. Output specification 100 m to 150 m per hour at typical 200 to 800 mm diameter, 0.55 to 1.20 mm gauge, length tolerance ±5 mm, leakage class A.
TDF flange former for tight-leakage exhaust
The TDF-IV flange former produces tight-leakage class duct for laboratory exhaust, kitchen exhaust risers and smoke management duct where leakage class A (the tightest class in AS 4254.2) is specified. The TDF flange seal with neoprene gasket delivers measurably lower leakage than slip-and-drive or S-and-drive seams.
Stainless capability for kitchen and chemistry lab
For the welded 304L stainless kitchen exhaust and chemistry lab fume hood exhaust, SBKJ supplies the stainless welding bay with TIG welding, pickling and passivation. Stainless duct fabrication runs at 8 to 15 m per hour depending on diameter and seam length — substantially slower than galvanised but typical for the required specification.
Shop floor footprint
The full SBAL-V plus SBTF plus TDF set occupies roughly 35 m of factory floor (15 m for the SBAL-V line including coil staging, 10 m for the SBTF spiral with strip handling, 6 m for the TDF station, 4 m for stainless welding). At single-shift operation, the set supports two large school projects per month or one university lab building per month. Two-shift doubles this throughput.
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FAQ
What ventilation rate does ASHRAE 62.1 require for a classroom?
ASHRAE 62.1 Table 6-1 specifies for ages 9 and above a classroom ventilation rate of 5 cfm per person plus 0.06 cfm per square foot of floor area, which combines into roughly 7.4 L/s per person at typical classroom densities. Younger student categories sit slightly higher per person. Australian designs reference both ASHRAE 62.1 and AS 1668.2 Table 3.2 (10 L/s per person for general occupancy) and design to whichever is greater, often producing 8 to 10 L/s per person for primary and secondary classrooms.
What materials are used for school HVAC ductwork?
Standard Australian school HVAC ductwork uses galvanised steel to AS 1397 grade Z275 (G90 imperial equivalent) at 0.55 to 1.00 mm gauge, fabricated to AS/NZS 4254.2. Internal acoustic lining is fibreglass duct liner at 25 mm or 50 mm. Fabric ductwork is increasingly common in retrofits, gymnasiums and large-volume zones. Science laboratory fume hood exhaust uses 304L stainless steel for chemistry, with PVC for trace acid systems. Kitchen exhaust uses 304L stainless to NFPA 96 / AS 1668.2 with welded longitudinal seams.
What is a typical lead time for a school HVAC project ductwork package?
For a new K-12 school of 600 to 1,200 students, the rectangular and round galvanised duct package typically runs 8 to 14 weeks from approved shop drawings to final delivery, fabricated on a single SBAL-V auto duct line in two-shift operation. Lab exhaust stainless duct adds 4 to 6 weeks because of welded seam fabrication and pickling. School holiday delivery windows align installation with January summer break or July mid-year break.
How does NABERS Education affect HVAC duct design?
The NABERS Energy for Schools tool rates whole-school energy use intensity in MJ per square metre per year. Higher star ratings push designers toward variable air volume systems, demand-controlled ventilation, low static pressure design (target external pressure under 250 Pa), fewer fittings per linear metre and aggressive duct insulation. Tightly fabricated TDF flange duct with low leakage class directly improves measured fan energy and contributes to a 5-star or 5.5-star NABERS Energy rating.
What are the acoustic NC targets for a classroom and lecture theatre?
AS/NZS 2107:2016 specifies NC-30 to NC-35 for primary and secondary classrooms, NC-25 to NC-30 for university lecture theatres, NC-25 to NC-30 for music rooms, NC-30 for libraries with study areas, and NC-35 to NC-40 for gymnasiums. Achieving NC-30 in a classroom typically requires 25 mm internal acoustic lining over the last 6 to 9 m of supply duct, an inline attenuator at each VAV terminal, and supply diffuser face velocity under 2.5 m/s.
What CO2 setpoint is used for demand-controlled ventilation in classrooms?
The standard control setpoint for classroom demand-controlled ventilation is 1,000 ppm CO2 (ASHRAE 62.1 informative recommendation), with some progressive Australian school authorities targeting 800 ppm for primary classrooms. CO2 sensors are wall-mounted at 1.2 to 1.5 m above the floor and modulate the outside air damper or VAV box to maintain setpoint. Post-COVID, many state education departments require continuous CO2 logging with parent or staff visibility through the building management system.
What machine specifications does SBKJ recommend for a school district fabricator?
For a fabricator supplying multiple K-12 schools per year, SBKJ recommends an SBAL-V Series VI auto duct production line in galvanised configuration (1.0 mm maximum gauge, 1,500 mm coil width), an SBTF-1500 spiral tubeformer for round duct serving lecture theatres and atriums, and a TDF-IV flange former for tight-leakage class duct for laboratory exhaust. The full set occupies roughly 35 m of factory floor and supports two large school projects per month at single-shift operation.
How is school holiday HVAC operation different from school day operation?
School holiday operation runs the building automation system in deep-setback mode: outside air dampers closed to minimum infiltration only, AHU fans cycled off for unoccupied hours, supply temperatures relaxed by 4 to 6 degrees C, no demand-controlled ventilation. Pre-occupancy purge is scheduled the morning of the first return-to-school day to flush the building with fresh air for two hours before students arrive. This setback strategy typically reduces school holiday energy use by 50 to 70 percent compared with school day operation.
