Childcare Centre, Kindergarten & OSHC HVAC Ductwork Guide — NQF, NQS Quality Area 3, AS 1668.2

Why childcare HVAC is its own discipline

An early learning room and a serviced office look superficially similar — same building shell, same ceiling void, similar floor area. They are not the same problem. The early learning room holds children whose lung tissue is still developing, whose immune systems are still being primed, who spend 8–10 hours a day in the same airspace, and who cannot articulate that the room is too cold, too dry, too loud, or too stale. The HVAC system has to do that work for them. And it has to do it under the National Quality Framework — a regulatory regime that gives ACECQA-appointed authorised officers the right to walk through a centre on a rating visit, ask for the mechanical drawings, ask to see the commissioning report, and rate the service against National Quality Standard Quality Area 3 — Physical Environment.

This guide is the same procedure SBKJ engineers walk through with mechanical contractors fitting out childcare projects across Australia — whether the operator is one of the listed groups (G8 Education, Affinity Education) or a single-site community kindergarten. The standards converge: AS 1668.2 for outdoor air, BCA Class 9b for the building classification, the Education and Care Services National Regulations for the operating regime, NQS Quality Area 3 for ongoing assessment, and the operator's own facility brief for everything not specified in the codes. Get any one of those layers wrong and the centre either fails compliance, generates parent complaints, or loses its NQS rating tier on assessment.

The good news: the design problem is bounded. Childcare facilities are typically 400–1,200 m² internal area, single-storey or two-storey, with a known cohort of room types — infant rooms, toddler rooms, preschool rooms, sleep rooms, nappy change facilities, bottle prep, kitchen, OSHC activity space, administration, staff room, indoor-outdoor transition. Once the room schedule is known 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.

The Australian regulatory stack for childcare HVAC

Five layers of regulation drive HVAC decisions in an Australian childcare fit-out. Most consultants name two or three. The five layers, in priority order, are:

1. National Construction Code (NCC) / Building Code of Australia (BCA) — governs the building classification (Class 9b assembly building for childcare), fire compartmentation, smoke management, mechanical ventilation, exit provisions and accessibility (under Premises Standards 2010). HVAC ductwork penetrating fire-rated boundaries must maintain the construction's FRL via correctly specified fire dampers; smoke compartments require smoke dampers; larger centres requiring smoke spill must comply with AS 1668.1.
2. AS 1668.2 — The use of ventilation and air conditioning in buildings — prescribes 12 L/s/person of outdoor air for childcare-classified spaces, sets the 25 L/s nappy change exhaust requirement, defines kitchen and laundry extract rates, and defines bottle prep humidity removal where applicable. AS 1668.2 is the mechanical ventilation backbone and is referenced by the BCA via NCC Specification F4.5.
3. Education and Care Services National Regulations — the operational regulations administered by state regulators (NSW Department of Education for NSW, Department of Education for Victoria, etc.) under the Education and Care Services National Law. These regulations cover staff-to-child ratios that drive peak occupancy (1:4 for under-2s, 1:5 for 2–3s, 1:11 for 3–5s in NSW), facility square-metre minimums (3.25 m² indoor per child, 7 m² outdoor), and safe sleep practice that drives sleep room temperature and acoustics.
4. National Quality Framework (NQF) and National Quality Standard (NQS) — Quality Area 3 Physical Environment — the quality assessment regime administered by ACECQA. Quality Area 3 has two standards: 3.1 (the design of the facility is appropriate for the operation of the service) and 3.2 (the service environment is inclusive, promotes competence and supports exploration and play-based learning). HVAC contributes to both standards. Authorised officers may request mechanical drawings, commissioning reports, balance reports and operational records.
5. Operator facility brief — the operator's internal engineering specification. The largest operators publish detailed briefs that go beyond the codes: G8 Education, Goodstart Early Learning, Affinity Education, Only About Children, Guardian Childcare & Education, KU Children's Services, Edge Early Learning, Imagine Childcare, KidsCo and Bright Horizons each maintain operator-specific specifications. Camp Australia and TheirCare run OSHC-specific briefs. State-funded preschools (NSW Department of Education preschools, Victorian kindergartens) follow state-issued specifications.

AS 1668.2 — the 12 L/s/person rule and what drives it

AS 1668.2 prescribes 12 L/s/person of outdoor air for childcare and early learning spaces. Compared to the 10 L/s/person rate used for general office occupancy, the 12 L/s figure is a 20% premium that catches first-time childcare designers off guard. Three factors drive it:

• Higher metabolic activity per body mass. Children at play generate more CO2 per kilogram of body weight than seated adults. The standard accounts for this by raising the per-person outdoor air rate.
• Higher peak occupancy density. The Education and Care Services National Regulations set a 3.25 m² indoor minimum per child, which is denser than typical office space (commonly 8–12 m² per person). At ratio, a 30 m² toddler room may legitimately hold nine children plus two educators — eleven people in 30 m² is high for any continuous-occupancy space.
• Elevated infectious-illness load. Group childcare is a known infectious-illness multiplier — RSV, influenza, gastrointestinal illness, hand-foot-mouth disease all spread efficiently in early learning settings. The 12 L/s/person rate is a partial dilution control alongside surface hygiene practice.

Designers should also cross-check ASHRAE Standard 62.1 outdoor air rates for educational and daycare occupancies. Many international operators reference both standards in their consultant brief, and the higher of the two governs. ASHRAE 62.1 itself was updated significantly in the post-pandemic period and now reflects more conservative outdoor air positions than earlier editions. Where the operator brief is silent on which standard governs, document the assumption in the design intent and the commissioning report.

A worked example: a 600 m² centre with licensed capacity for 90 children at peak ratio (with 12 educators) totals 102 occupants. At 12 L/s/person the outdoor air requirement is 1,224 L/s — approximately 4,400 m³/h. That outdoor air load drives AHU sizing, energy recovery (heat wheel or plate exchanger) economics, and ductwork sizing for the outdoor air pickup. Centres without heat recovery on the outdoor air feed pay for that decision in winter heating bills for the entire 10–15 year asset life.

Zoning by age cohort — the design pattern that survives NQS rating

The dominant zoning error in childcare HVAC design is treating the building as one open-plan space with a single AHU. The design pattern that survives both code compliance and NQS rating zones the plant by age cohort, recognising that infant rooms have different setpoints, different acoustics, different occupancy patterns and a different illness profile from preschool rooms.

The zoning pattern SBKJ engineers recommend for a typical 90-place centre:

• Zone 1 — Infant rooms (0–2 years). Dedicated room AHU, tight setpoint deadband, MERV 13 minimum filtration with HEPA H13 progressive operators. Return air path engineered to avoid drawing across the nappy change facility. Independent VFD on the supply fan to allow night-mode operation during winter close-down.
• Zone 2 — Toddler rooms (2–3 years). Multi-zone AHU acceptable. VAV with reheat in east-west buildings to handle solar gain differential. Diffuser layout avoiding floor mat areas where children sit.
• Zone 3 — Preschool rooms (3–5 years). Multi-zone AHU acceptable. Higher activity level than toddler rooms tolerates slightly higher diffuser face velocities but still well within acoustic targets.
• Zone 4 — Sleep rooms. Dedicated AHU branch, lower setpoint, tightest acoustic specification (NC-30), dim lighting interlocked with night-mode HVAC. Separate from general activity rooms.
• Zone 5 — Nappy change and bottle prep. Dedicated extract systems, no recirculation, direct to outside. Negative pressure relative to adjacent learning rooms to prevent odour migration.
• Zone 6 — OSHC activity space. Out of school hours care typically activates between 0700–0900 and 1500–1830, with the room dormant during the school day. AHU should support a programmable schedule with rapid pull-down at 0630.
• Zone 7 — Kitchen, laundry, services. AS 1668.2 plus AS 4674 for food preparation, dedicated extract systems, food-grade duct materials within the kitchen envelope.
• Zone 8 — Administration and staff areas. Standard office-grade ventilation (10 L/s/person), separate AHU from learning room zones.
• Zone 9 — Indoor-outdoor transition vestibule. Pre-conditioning buffer between climate-controlled indoor space and outdoor play area. Sized at approximately 50% of adjacent learning room rate.

The zoning decision flows from the room schedule. Once zoning is fixed the ductwork specification is mechanical: trunk sizes, branch sizes, diffuser locations, return air paths, exhaust paths and damper schedule all fall out of the zoned plant strategy.

Infant room (0–2 years) — the highest-precision room in the centre

Infant rooms hold children aged 0–2 years. Infants thermoregulate poorly, are cared for at floor level much of the day, sleep multiple times per shift, are fed via bottle (sometimes via direct breast feeding by visiting parents), and have nappies changed every 2–3 hours. The HVAC system has to handle all of this without producing drafts on the floor, without producing noise that wakes sleeping infants, without recirculating odour from the nappy change facility, and without elevating humidity from the bottle steriliser.

Design conditions: 22–24°C, 40–60% relative humidity, ±0.5°C deadband. The deadband matters — a 1.5°C swing felt by an adult educator is barely perceptible, but for a six-month-old in a sleep bag it can mean waking from cold or sweating from heat. Tight deadband requires a competent VAV with reheat strategy, modulating control valves rather than two-position, and a high-resolution room sensor not located adjacent to a diffuser jet or solar window.

Filtration: MERV 13 minimum, HEPA H13 specified by progressive operators. The filtration class is driven by paediatric respiratory health rationale: children under five are presented to GPs with respiratory illness more than three times the population average, and reducing PM2.5 and bioaerosol loading in the air they breathe for 8–10 hours a day is one of the few interventions facility owners directly control. SBKJ duct lines are sized for either filter class; specifying HEPA H13 raises fan static pressure by approximately 250 Pa over a MERV 13 baseline, which the AHU and ductwork must accommodate.

Diffuser layout: Avoid direct overhead drops onto the cot floor area. Linear slot diffusers along the room perimeter with throw across the room (rather than directly down) prevent drafts on sleeping infants. Return grilles located near the room centre, not adjacent to the nappy change zone.

Return air path: The infant room return path must not draw across the nappy change room. The simplest engineering solution is a ducted return picking up at the opposite side of the room from the nappy change door, with the nappy change room held under negative pressure by its dedicated 25 L/s exhaust.

Acoustic target: NC-30 at minimum, NC-25 in the cot/sleep portion of the room. Diffuser regenerated noise from undersized ductwork is the most common acoustic non-conformance — face velocity below 4 m/s in supply branches and 3 m/s in return branches is a workable rule of thumb, with attenuators sized via manufacturer dB-per-attenuator data.

Sleep area within infant room: Many infant rooms include a discrete sleep zone within the same room rather than a separate sleep room. Provide a dimmable lighting circuit interlocked with HVAC night-mode (lower temperature setpoint, lower fan speed, lower light level) for the sleep portion of the room.

Toddler and preschool rooms — the largest occupancy load

Toddler rooms (2–3 years) and preschool rooms (3–5 years) carry the largest occupancy load in a typical centre — at NSW ratios, a single room can hold 11 children with one educator in the preschool age band. The HVAC system has to handle peak occupancy through morning arrival, mid-morning peak activity, post-lunch quiet time, afternoon activity, and end-of-day pickup with consistently good comfort.

Design conditions: 21–23°C, 40–60% RH. Slightly cooler than infant rooms because the children are larger, more active, and more able to regulate their own thermal experience by adding or removing layers and by moving around the room.

Multi-zone VAV with reheat: Toddler and preschool rooms in east-west oriented buildings experience large solar gain differentials between rooms — a north-facing room in winter receives substantial passive heat gain, while a south-facing room receives little. Multi-zone VAV with reheat (or DOAS plus terminal heat pumps) handles this differential without overcooling the south rooms to satisfy the north rooms.

Diffuser layout: Avoid floor mat areas where children sit and lie. Throw diffusers should aim across the room rather than directly down onto play zones. Return grilles centrally located, away from doorways where diffused outdoor air during drop-off and pickup creates short-cycle conditions.

Acoustic target: NC-35 in active play rooms. Lower than offices because parental complaints about noisy AHUs are routine — a parent dropping off at 0730 and noticing fan noise will mention it at the rating visit if asked.

CO2 monitoring: A CO2 logger in each room provides an objective ventilation-effectiveness signal during NQS rating visits. CO2 above 1,200 ppm during peak occupancy is a strong signal that outdoor air supply is undersized or the AHU outdoor air damper is not opening to design position. Many operators now specify CO2 displays in each room as a parental-confidence feature.

Sleep rooms — the acoustically tightest spaces in the centre

Sleep rooms hold sleeping children — typically toddlers in cots and preschool children on stretcher beds for the post-lunch sleep period. Sleep room HVAC has three jobs: keep the room cooler than activity rooms (19–21°C — supporting safe sleep practice), keep the room quiet (NC-30 or below), and keep the room dim (lighting interlocked with HVAC night-mode).

Design conditions: 19–21°C, 40–60% RH. Cooler than activity rooms because cooler ambient supports deeper sleep and reduces heat-related sleep disruption. The setpoint can be programmed to drop by 1–2°C during the active sleep period (typically 1230–1430) and recover to activity-room setpoint before the children wake.

Acoustic target NC-30: NC-30 corresponds to approximately 35 dBA in a typical sleep room — quiet enough that sleeping children are not disturbed by AHU noise, diffuser regenerated noise, or duct-borne transmission from adjacent activity rooms. Hitting NC-30 reliably requires:

• Sized ductwork — supply face velocity below 4 m/s, return face velocity below 3 m/s.
• Correctly specified attenuators — typically a dissipative splitter attenuator on the supply branch within 2–3 m of the sleep room, sized for 15–25 dB insertion loss across mid-frequency bands.
• Acoustic duct lining on supply and return runs within 6 m of the sleep room — see our acoustic duct lining and attenuator guide for detail on lining materials, thickness selection and regenerated noise calculation.
• Vibration isolation on the AHU servicing the sleep room — spring isolators on the AHU base, flexible connectors at the fan discharge and return, and either a flexible canvas connector or a flexible duct connector at the AHU-to-ductwork transition.
• Avoidance of direct line-of-sight from the AHU supply fan through the ductwork to the sleep room diffuser — ductwork bends and attenuators break that line of sight and reduce duct-borne fan noise transmission.

Lighting interlock: A dimmable lighting circuit interlocked with HVAC night-mode allows the sleep room to be darkened simultaneously with the temperature setpoint dropping and the fan speed reducing. The simplest implementation is a single time-clock signal driving the BMS night-mode strategy across both lighting and HVAC.

Nappy change rooms — where most childcare HVAC compliance fails

The nappy change facility is the single most common source of AS 1668.2 non-conformance in Australian childcare design. The standard mandates a minimum 25 L/s mechanical exhaust direct to outside, with no recirculation, on a dedicated fan running continuously during operating hours. Three failure modes recur:

1. Exhaust shared with toilet exhaust. Sharing the nappy change exhaust with adjacent toilet exhaust is acceptable only if the combined system is correctly interlocked, run continuously, and sized for the combined load. Many fit-outs share the duct but underrun the fan, leaving the nappy change facility under-exhausted at peak.
2. Exhaust grille located across the room from the change table. Capturing odour and bioaerosols at source requires the exhaust grille directly above the change table, typically within a 1.5 m radius. A grille at the opposite end of the room captures the diluted plume after odour has migrated into the adjacent learning room.
3. Recirculation through the AHU. A fundamental code breach: nappy change air must not be recirculated through the AHU. Ducted exhaust direct to outside, no return air pickup in the nappy change facility, and the room held under negative pressure relative to adjacent learning rooms.

Migration of odour and bioaerosols from nappy change facilities to adjacent learning rooms is one of the top complaint categories in Education and Care Services regulator inspections. The mechanical solution is straightforward: 25 L/s minimum, dedicated fan, direct to outside, exhaust grille over the change table, room held under negative pressure. Get any one of those four wrong and the room fails on first inspection.

Bottle preparation and steriliser — humidity removal

Bottle preparation and steriliser areas generate humidity from steam steriliser cycles, hot water bottle warming, and dishwashing of bottle parts. The humidity migrates into adjacent infant rooms if not controlled, elevating room RH above the 60% upper bound and encouraging mould growth in ceiling voids and behind cabinetry.

The mechanical solution is a dedicated extract for the bottle prep area, typically 15–25 L/s on a dedicated fan direct to outside, with the make-up air drawn from the adjacent infant room (which is itself supplied with conditioned outdoor air). The bottle prep area runs slightly negative relative to the infant room, drawing air out of the infant room, through the bottle prep, and to outside. This pattern controls both humidity and any cooking odour from the bottle warming process.

Where bottle prep is co-located with kitchen functions (some smaller centres combine the spaces), the kitchen extract specification (AS 1668.2 plus AS 4674) governs and the bottle prep extract becomes a sub-set of the kitchen extract.

The indoor-outdoor transition vestibule

Children in regulated childcare spend a substantial portion of the day outdoors — the Education and Care Services National Regulations mandate 7 m² of outdoor space per child, more than double the indoor requirement, and the curriculum is designed around outdoor-indoor transitions. Children move between climate-controlled indoor space and outdoor play multiple times per session.

Without an entry vestibule, every door opening creates a short-cycle event for the room AHU — outdoor air plus children plus educators all moving through a single doorway, dropping room temperature by 2–3°C in winter and raising it by 2–3°C in summer until the AHU recovers. Over a day with 8–10 outdoor transitions, the cumulative energy cost is significant and the comfort experience for children indoors is poor.

The design solution is an entry vestibule between the outdoor play area and the indoor learning rooms — a pre-conditioning buffer space typically 4–6 m² in floor area, sized at approximately 50% of the adjacent learning room outdoor air rate. The vestibule conditions the air slightly toward the indoor setpoint before the second door opens into the learning room, reducing the magnitude of the short-cycle event and protecting the room AHU from working hard against repeated door openings.

HEPA filtration — when to specify it for childcare

HEPA H13 filtration is not mandated by AS 1668.2 for general childcare ventilation. The MERV 13 baseline that contemporary specifications adopt captures the majority of PM2.5 and most bioaerosol loading, and is what most consultant briefs require. HEPA H13 — which captures 99.95% of particles at 0.3 micron — is reserved for specific use cases:

• Infant rooms. The youngest cohort, longest in-room duration per day, weakest immune system. Progressive operators (Bright Horizons, Only About Children, Guardian Childcare & Education) specify HEPA H13 in infant rooms as a parental-confidence feature.
• Isolation/illness rooms. A small room set aside for children who become unwell during the session, where they wait for parent collection. HEPA H13 reduces cross-contamination risk to the educator providing care.
• Centres located near major roads or industrial sources. Centres with elevated outside-air PM2.5 — proximity to freeways, airport flight paths, industrial corridors — benefit from HEPA H13 on outdoor air supply regardless of room type.

The cost driver of HEPA H13 is fan static pressure. A clean HEPA H13 filter runs around 250 Pa at design face velocity; a dirty filter approaching change-out runs around 600 Pa. The AHU and ductwork must accommodate that pressure delta, which means selecting a higher-static fan, sizing the duct branches for the higher pressure drop, and budgeting for more frequent filter replacement (typically twice a year for HEPA H13 versus annually for MERV 13).

SBKJ duct lines are sized for either filter class. The SBAL-III galvanized standard specification handles MERV 13 face velocities natively, and the duct specification for HEPA H13 simply tightens the face velocity range and raises the gauge schedule on higher-pressure branches.

VOC and material emissions — the Green Star angle

A newly fitted-out childcare centre experiences elevated total volatile organic compound (TVOC) loading for 6–12 weeks post-handover as sealants, adhesives, paint, floor coverings, joinery and acoustic insulation off-gas residual VOCs. Children and educators occupying that space during the off-gas period are exposed to TVOC levels significantly above steady-state.

The Green Star Indoor Environment credit category provides a structured approach to specifying low-emitting materials — paints, sealants, adhesives, floor coverings, ceiling tiles, acoustic insulation and duct insulation that meet specified emission limits (typically South Coast Air Quality Management District Rule 1168 for sealants, or the ECO-INSTITUT certification for materials more broadly). Larger operators increasingly require Green Star compliance in the consultant brief, and even where not formally required, the principles are good practice.

For ductwork specifically, this means specifying duct sealants and gasket materials to low-emission standards, avoiding fibreglass acoustic linings where alternative materials are available (or ensuring the lining is fully encapsulated and edge-sealed to prevent fibre release), and running a pre-occupation purge cycle — typically 72 hours of 100% outdoor air at full design flow before children occupy the building. The pre-occupation purge is one of the cheapest IAQ interventions available and is increasingly written into operator handover protocols.

BCA Class 9b — the building code implications

Under the National Construction Code Volume One, an early childhood education and care premises is typically classified as Class 9b — a building used for assembly, including a building used for educational purposes. This classification triggers a specific set of requirements that flow into HVAC ductwork design:

• Fire compartmentation. Class 9b buildings have fire-resistance level (FRL) requirements that vary with size, height and rise of stories. Ductwork penetrating fire-rated walls or floors must maintain the FRL via correctly specified fire dampers — typically 60/60/60 or 90/90/90 dampers depending on the construction's required FRL. Damper installation must be witnessed by the certifier and drop-tested annually.
• Smoke compartmentation. Larger centres may be divided into smoke compartments with smoke dampers at compartment boundaries. The smoke damper assembly must include the damper, the actuator, and the smoke detection wiring back to the fire alarm panel.
• Smoke spill. Centres exceeding the size threshold may require a smoke spill system designed to AS 1668.1. Smoke spill ductwork is specified differently from comfort ductwork — heavier gauge, smoke-rated penetrations, fire-rated supports, and survival-temperature insulation.
• Mechanical ventilation. Class 9b mandates mechanical ventilation per AS 1668.2 — natural ventilation alone is not acceptable for childcare-classified spaces. This drives the AHU specification, the ductwork sizing and the outdoor air provisions.
• Exit provisions. Exit door layouts in Class 9b drive the room geometry and therefore the supply and return diffuser layout. Diffusers should not be located such that a child standing on a piece of furniture could touch a hot supply diffuser face.
• Accessibility (Premises Standards 2010). The Disability (Access to Premises — Buildings) Standards 2010 apply to childcare facilities. Accessibility considerations include the height of supply and return grilles within reach of children, controls accessible to educators with disabilities, and tactile and auditory signalling not interfered with by AHU noise.

AS 4674 — where food preparation occurs

Most Australian childcare centres prepare a cooked midday meal on site rather than receiving prepared meals from a central kitchen. Where food is prepared on site, AS 4674 — Construction and fit-out of food premises — applies in addition to AS 1668.2.

The HVAC implications are concentrated on the kitchen envelope:

• Kitchen exhaust hood sized per AS 1668.2 and AS 4674, typically capturing 75–80% of cooking heat and odour at source.
• Dedicated make-up air to replace exhausted air, typically 90% of the exhaust rate to maintain slight negative pressure relative to adjacent learning rooms.
• Food-grade duct materials within the food preparation envelope — galvanized or stainless steel, no internal acoustic linings that could harbour grease, smooth-bore for cleanability.
• Separation of kitchen exhaust ductwork from learning room HVAC — kitchen exhaust must not share trunks with comfort ducting.
• Grease-laden vapour exhaust meeting AS 1668.1 fire requirements — the kitchen exhaust riser and discharge are part of the fire engineering for the building.

For SBKJ duct lines, the kitchen envelope typically uses the same SBAL-III galvanized specification as the rest of the centre, with stainless steel transitions where the duct passes through the cooking hood and an external grease trap upstream of the exhaust fan.

Acoustic targets — NC-30 sleep, NC-35 activity

Acoustic NC ratings are now routinely measured during NQS rating visits — partly because parents notice noisy HVAC at drop-off and pickup, and partly because diffuser regenerated noise is a strong signal of undersized ductwork. The targets to design to are:

• Sleep rooms — NC-30. Approximately 35 dBA in a typical sleep room. Quiet enough that 30 sleeping toddlers are not disturbed.
• Active learning rooms — NC-35. Approximately 40 dBA. Below conversation level, allowing educators to conduct group story time without competing with HVAC noise.
• Administration and staff areas — NC-40. Approximately 45 dBA. Standard office acoustic level.
• Kitchen and back-of-house — NC-45 acceptable. Higher acoustic level acceptable where children are not the primary occupants.

Hitting these targets reliably requires the duct sizing rules of thumb noted earlier (supply face velocity below 4 m/s, return below 3 m/s for sleep and active rooms), correctly specified attenuators, acoustic duct lining within 6 m of acoustically sensitive rooms, and vibration isolation on the AHU. Our acoustic HVAC duct lining and attenuator guide covers the lining material selection, thickness rules, regenerated noise calculation and attenuator sizing in detail.

Energy benchmarking — NABERS for Schools and Climate Active

The energy performance of a childcare centre is increasingly tracked via NABERS for Schools (the National Australian Built Environment Rating System extension covering educational facilities including early learning and OSHC) and via the Climate Active certification trend (formerly the National Carbon Offset Standard). Larger operators (G8 Education, Goodstart Early Learning, Affinity Education) are increasingly writing target NABERS ratings into the consultant brief, and Climate Active certification appears as a parental-marketing differentiator at the premium end of the market.

For HVAC ductwork specifically, the energy implications are:

• Heat recovery on outdoor air. A heat wheel or plate exchanger on the outdoor air feed recovers 60–80% of the energy in the exhaust stream during winter heating. At 12 L/s/person and 100 occupants, the energy at stake is significant — heat recovery typically pays back within 3–5 years.
• VFD on supply and return fans. Variable speed drives allow the AHU to track real occupancy via CO2 trim or temperature trim, dropping fan energy by 40–60% during shoulder hours.
• Duct sizing for low pressure drop. Slightly larger duct sizes reduce fan energy across the 10–15 year asset life. The capital premium for upsizing duct branches by one nominal size pays back rapidly through reduced fan energy.
• Insulation specification. External duct insulation prevents condensation in summer and reduces heat loss in winter — both energy savings.
• AHU efficiency. High-efficiency motors (IE3 or IE4), high-efficiency coils, low-pressure-drop filter banks all reduce the building energy budget.

SBKJ machine configuration for childcare ductwork

For Australian childcare fit-outs SBKJ engineers recommend the following standard machine configuration:

• SBAL-III galvanized as standard duct line. The SBAL-III is the workhorse for childcare, education and healthcare ductwork — robust, AS/NZS 4254-1 compliant, MERV 13+ rated face velocities natively, and capable of producing the rectangular duct sizes typical of childcare branch and trunk ductwork. See our comparison of SBAL-V versus SBAL-III for the specification differences.
• Z275 minimum galvanizing for coastal centres. Centres in Sydney, Brisbane, Perth and other coastal cities should specify Z275 minimum galvanizing — the higher zinc coating mass extends duct life under chloride exposure.
• MERV 13+ rated face velocities on all rooms. Duct sizing tables for childcare runs assume MERV 13 minimum and accommodate HEPA H13 in infant rooms.
• TDF flanged connections for pressure-tested seams. TDF flanges allow pressure-tested duct seams that hold to 1,000 Pa with zero detectable leakage — important for both energy performance and for indoor pressure relationship integrity (nappy change negative pressure, infant room neutral pressure).
• Acoustic lining option for sleep room branches. SBKJ duct lines can produce both bare and pre-lined duct sections. Sleep room branches are typically specified with acoustic lining within 6 m of the diffuser.
• Spiral round duct for higher-pressure runs. Where higher pressure runs are required (HEPA H13 infant room branches), spiral round duct provides better pressure performance than rectangular at equivalent face velocity.

For mechanical contractors fitting out multiple centres a year, an in-house duct line with this configuration produces ductwork to the operator's specification in batch sizes that match the project pipeline — typically two to three centres per quarter for a mid-size mechanical contractor. The capital payback against outsourced ductwork is typically 18–30 months.

The largest Australian childcare operators and how they specify HVAC

The Australian regulated childcare sector is dominated by a small number of large operators alongside hundreds of single-site community centres and state-funded preschools. The largest operators publish detailed facility briefs that mechanical contractors typically work to:

• G8 Education. The largest ASX-listed operator. Multi-brand portfolio. Centralised facility specifications for new fit-outs, with regional engineering oversight.
• Goodstart Early Learning. The largest not-for-profit operator. Strong sustainability and energy benchmarking focus, NABERS for Schools alignment in the brief.
• Affinity Education. Multi-brand operator with significant fit-out pipeline. Specifications typically reference AS 1668.2, BCA Class 9b, MERV 13 minimum filtration.
• Only About Children. Premium positioning. HEPA H13 specified in infant rooms as standard. Acoustic NC-30 in sleep rooms as standard. Often references both AS 1668.2 and ASHRAE 62.1.
• Edge Early Learning. Queensland-headquartered operator. Standard AS 1668.2 specifications, focus on outdoor-indoor transition design.
• Guardian Childcare & Education. Premium positioning across major metro markets. Dedicated infant room AHU is standard, HEPA H13 progressive.
• KU Children's Services. Long-established not-for-profit. Strong focus on sustainability and Indigenous engagement. Standard AS 1668.2 specifications.
• Imagine Childcare. Multi-site operator. Standard specifications referencing AS 1668.2 and BCA Class 9b.
• KidsCo. Mid-size multi-site operator.
• Bright Horizons. Global operator with Australian presence. References both Australian standards and international parent specifications — ASHRAE 62.1, US-style HEPA in infant rooms.
• Camp Australia. Largest OSHC (out of school hours care) operator. OSHC fit-outs share school facilities, so HVAC specifications are typically driven by the school's existing AHU plant rather than a dedicated OSHC AHU.
• TheirCare. Large OSHC operator. Similar profile to Camp Australia.
• NSW Department of Education preschools. State-funded preschools attached to NSW public schools. Specifications follow NSW DoE standard mechanical specifications.
• Victorian kindergartens. Funded by the Victorian Department of Education. Specifications follow Victorian Department mechanical standards.

Across these operators the common technical positions are: AS 1668.2 for ventilation, BCA Class 9b for the building, MERV 13 minimum filtration, NC-30 for sleep rooms, 25 L/s for nappy change exhaust, NABERS for Schools energy benchmarking, and Green Star low-emitting materials. Premium operators add HEPA H13 in infant rooms, dedicated infant room AHUs, Climate Active certification, and tighter acoustic targets.

Commissioning and the NQS evidence pack

Commissioning a childcare HVAC system is not complete when the AHU runs and the rooms are at temperature. The handover deliverable is an evidence pack that survives an NQS rating visit and an Education and Care Services regulator inspection. The pack should include:

1. Design intent statement. What the system was designed to deliver — outdoor air rates, temperature setpoints, humidity bands, acoustic targets, filtration class, fire-rated separations.
2. Calculated airflow schedule. Room-by-room calculated supply, return and exhaust airflows, with the AS 1668.2 reference for each calculation.
3. Measured airflow report. Room-by-room measured airflows at every grille, by an independent commissioning agent, against the calculated values.
4. AHU performance test record. Coil performance, fan curves, motor draw, filter pressure drop at clean and dirty conditions, control valve stroke tests.
5. Pressure relationship record. Verified negative pressure in nappy change rooms, neutral pressure in infant rooms, neutral or slightly positive pressure in learning rooms, negative pressure in kitchen back-of-house.
6. Acoustic measurement report. NC ratings measured at each room type at design fan speed, witnessed against the design targets.
7. Fire damper installation and drop-test certificates. Witnessed installation of every fire damper, with a drop-test certificate for each.
8. Smoke damper test certificates. Where applicable.
9. Filter change-out schedule. Documented schedule for MERV 13 (annual) and HEPA H13 (twice yearly), with manufacturer guidance on pressure drop trigger points.
10. Maintenance manual for the centre director. A non-engineer-readable summary of what the system does, how to identify obvious faults (room not cooling, AHU not running, alarm panel showing fault), and who to call.
11. BMS operator training certificate. Training delivered to the centre director and at least one senior educator on the operator interface.
12. Pre-occupation purge log. Documented 72-hour pre-occupation purge before children occupy the building.

This pack is the foundation for both NQS rating and ongoing essential safety measures compliance. The marginal cost of preparing the pack at handover is small; the cost of trying to reconstruct it three years later when the regulator asks is large.

Ongoing operational verification

Childcare HVAC systems run 50 weeks a year, 11 hours a day, with a vulnerable user population. Ongoing verification is part of the service model:

• Quarterly AHU service. Coil clean, filter inspection, belt/coupling inspection, control valve stroke test, drain pan clean.
• Annual ductwork inspection. Visual inspection of internal duct condition, joint integrity, acoustic lining condition, damper position verification.
• Annual filter replacement. MERV 13 typically annual; HEPA H13 typically twice yearly. Pressure-drop logging gives an objective trigger.
• Annual fire damper drop test. Mandated by the building's essential safety measures schedule.
• Biennial duct cleaning. Internal duct cleaning with NADCA-style protocols, with before-and-after photographs.
• Continuous CO2 logging. CO2 in each learning room as an objective ventilation-effectiveness indicator. Trend lines should not exceed 1,200 ppm during peak occupancy.
• Continuous temperature and humidity logging. Trend lines should sit within the room-type design bands (22–24°C infant, 21–23°C activity, 19–21°C sleep).

Many operators are now writing continuous monitoring requirements into the consultant brief, with the data accessible to the regional facility manager via a cloud BMS. The cost of this monitoring layer is small relative to the operational risk it manages.

OSHC — out of school hours care has its own profile

Out of School Hours Care (OSHC) is the regulated childcare segment serving primary school children before and after school, on pupil-free days, and during school holidays. The dominant operators are Camp Australia and TheirCare, with smaller operators including Junior Adventures Group and a long tail of single-school OSHC programs run by parent committees or the school itself.

OSHC operates inside school facilities — typically the school hall, multipurpose room, or a dedicated OSHC space within the school footprint. Because OSHC inherits the school's existing AHU plant, the HVAC specification work is different from a greenfield childcare fit-out. The questions to answer for OSHC HVAC compliance are:

• Is the existing AHU sized for the OSHC operating window? OSHC activates 0700–0900 and 1500–1830 — both periods outside the typical school AHU operating schedule. The AHU may need a programmable schedule extension and rapid pull-down at 0630.
• Does the existing ventilation rate meet 12 L/s/person at OSHC ratio? School halls are typically designed to 10 L/s/person for infrequent assembly use. OSHC uses the same space at higher density, for longer hours, with younger children. The outdoor air rate often needs an upgrade.
• Are there nappy change facilities? Most OSHC programs serve children aged 5+ and do not include nappy change. Where the OSHC program serves Kindy/Prep children with toileting still in transition, the 25 L/s exhaust requirement applies.
• Is the acoustic environment acceptable? School halls are acoustically lively spaces designed for performance, not for after-school homework time. Acoustic improvements (lining, attenuators, rebalancing) often form part of an OSHC fit-out.
• Is the OSHC space clearly demarcated for NQS rating purposes? Where OSHC shares space with curricular school activities, the NQS rating visit assesses the OSHC operating period and configuration specifically.

For mechanical contractors, OSHC fit-outs are typically smaller in scale than greenfield childcare but more numerous — Camp Australia and TheirCare each operate several hundred sites across Australia, with regular refurbishment cycles. The work tends to focus on AHU upgrades, ductwork extensions for new room configurations, and acoustic improvements rather than full new-build mechanical packages.

State-funded preschools and Victorian kindergartens

Alongside the listed and not-for-profit operators, a substantial portion of Australian early learning is delivered through state-funded preschools and kindergartens — NSW Department of Education preschools attached to NSW public schools, and the Victorian kindergarten sector funded by the Victorian Department of Education.

State-funded facilities follow state-issued mechanical specifications which broadly track the National standards (AS 1668.2, BCA Class 9b) but include additional state-specific requirements:

• NSW DoE publishes a Mechanical Services Standard that specifies AHU types, control strategies, and BMS interfacing requirements for all NSW education infrastructure including attached preschools.
• Victorian DET publishes equivalent specifications via the Victorian School Building Authority for state schools and kindergartens.
• Both states are increasingly requiring NABERS for Schools rating in the design brief and mandate continuous monitoring of indoor air quality for new builds.
• Kindergartens funded under the Victorian Free Kinder reform — the rapid expansion of kindergarten places announced in recent years — are typically built or fitted out under a standard design template, which includes a standard mechanical specification.

For mechanical contractors, state-funded work flows through the relevant state department's panel of approved contractors, and the design specifications are generally fixed at the panel-tender stage rather than negotiated per project. Working to the state's standard specification is usually more efficient than attempting to substitute alternative approaches.

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:

• Education, school and university HVAC duct guide — covers the broader school sector including primary, secondary, and tertiary institutions, where childcare and OSHC sit at the entry end of the educational pipeline.
• Hospital and healthcare HVAC duct guide — covers paediatric wards, neonatal units and other healthcare environments where the engineering precision required is even tighter than infant rooms in childcare.
• AS 1668.2 Australian ventilation code reference — the reference guide to the standard cited throughout this article, with worked examples for each occupancy class.
• SBAL-V versus SBAL-III — the machine specification comparison for the duct lines recommended in this guide.
• Acoustic HVAC duct lining and attenuator guide — the acoustic detail behind the NC-30 sleep room target.

How SBKJ supports childcare projects

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

• Duct line specification and supply. SBAL-III galvanized standard configuration with the options described above — Z275 galvanizing, TDF flanges, acoustic lining capability, filter-class-appropriate face velocities.
• Engineering review. Review of the consultant's mechanical specification against AS 1668.2, BCA Class 9b, the operator brief and the NQS Quality Area 3 evidence requirements. Free for shortlisted projects.
• Commissioning support. Pre-handover review of the commissioning evidence pack, with sample reports from comparable centres for comparison.

Talk to an SBKJ engineer about your childcare project →

FAQ

What is the AS 1668.2 outdoor air rate for an Australian childcare centre?

12 L/s/person — a 20% premium over the 10 L/s/person rate for offices, reflecting higher metabolic activity, denser occupancy at peak ratios, and elevated infectious-illness load. Cross-check ASHRAE 62.1 where the operator brief references it; the higher rate governs.

What temperature should an infant room be at?

22–24°C with 40–60% RH and a tight ±0.5°C deadband, on a dedicated room AHU. Toddler and preschool rooms run slightly cooler at 21–23°C; sleep rooms run cooler still at 19–21°C to support safe sleep practice.

How does NQS Quality Area 3 affect HVAC?

NQS Quality Area 3 — Physical Environment — is assessed by ACECQA-appointed authorised officers during NQS rating visits. The HVAC system contributes to Standards 3.1 and 3.2. Mechanical drawings, commissioning reports and balance reports are routinely requested at rating.

Why does nappy change need 25 L/s direct exhaust?

AS 1668.2 mandates a minimum 25 L/s mechanical exhaust direct to outside, dedicated fan, no recirculation, running continuously during operating hours. The exhaust grille should be over the change table to capture odour and bioaerosols at source. This is the most common AS 1668.2 non-conformance in childcare.

Do childcare centres need HEPA filtration?

Not mandated — MERV 13 minimum is the contemporary baseline. HEPA H13 is reserved for infant rooms (progressive operators), isolation/illness rooms, and centres in elevated-PM2.5 locations. SBKJ duct lines are sized for either filter class.

What acoustic level should sleep rooms target?

NC-30 — approximately 35 dBA. Hitting NC-30 reliably requires sized ductwork (supply face velocity below 4 m/s, return below 3 m/s), correctly specified attenuators, and acoustic duct lining within 6 m of the sleep room.

Is a childcare centre Class 9b under the BCA?

Yes — typically. This drives mechanical ventilation requirements, fire and smoke compartmentation, exit provisions, and accessibility (Premises Standards 2010). Ductwork penetrating fire-rated boundaries must maintain the FRL via fire dampers.

Who are the largest Australian childcare operators?

G8 Education (largest ASX-listed), Goodstart Early Learning (largest not-for-profit), Affinity Education, Only About Children, Edge Early Learning, Guardian Childcare & Education, KU Children's Services, Imagine Childcare, KidsCo, Bright Horizons. OSHC is dominated by Camp Australia and TheirCare. State-funded preschools include NSW Department of Education preschools and Victorian kindergartens.