Marina, Yacht Club & Dry Stack Boat Storage HVAC Ductwork — Australian Coastal Facilities Engineering Guide

Why marina HVAC ductwork is its own engineering discipline

A marina is not a single building. It is a precinct that strings together a hospitality-grade clubhouse, a function space that hosts the season's presentation nights, a retail chandlery, a refit and service workshop with composite repair and engine service, a marine fueling station with petrol and diesel and often LPG cylinder fills, a hardstand and dry stack storage hall, member toilets and change rooms, a race control room with weather feeds and radio, and a network of equipment and pump rooms that all sit within a few hundred metres of the breakwater. Each of these has a different ventilation rate, a different temperature target, a different acoustic specification and — most consequentially — a different relationship with the salt aerosol that drifts in from the open water.

An HVAC ductwork specification that treats all of this as one building will fail in two ways. It will under-ventilate the function room on a regatta presentation night and over-ventilate the chandlery. It will run galvanised duct outside the clubhouse envelope and watch it corrode in three years. It will ignore the hazardous-area zoning around the fueling station and put non-Ex-rated diffusers within a Zone 1 envelope. The marina HVAC designer who keeps the precinct as one zone is the designer who calls SBKJ in year four to remake half the duct system in 316L stainless.

This guide is the same procedure SBKJ engineers run when our customers ask us to size and specify ductwork for a marina or yacht club project. We have built duct for marinas operated by d'Albora Marinas across Sydney and Brisbane, for the royal yacht squadrons of New South Wales, Victoria, Tasmania, Queensland and Western Australia, and for the Whitsundays and Sunshine Coast charter and bareboat operators. The standards quoted are Australian (AS 1668.2 ventilation, AS/NZS 60079 hazardous area, AS 1940 flammable liquid storage, AS/NZS 4254 ductwork construction) layered with the international ISO 9223 atmospheric corrosivity classification because the marine atmosphere is the same chemical environment whether you are at Sanctuary Cove on the Gold Coast or Bermagui on the Sapphire Coast.

The Australian marina industry — operators, associations and project pipeline

Australia has roughly 380 commercial marinas and yacht clubs ranging from a 20-berth fishing co-operative to the 600-plus berth precincts of the Gold Coast and Sydney. The industry is represented at peak-body level by The Australian Marine Industries Association which covers the broader marine manufacturing and refit ecosystem, and by the Marinas Industry Association of Australia (MIAA) which is the dedicated trade body for marina operators, accreditation under the Gold Anchor Scheme, and the technical standards work that drives capital expenditure cycles.

The dominant operator is d'Albora Marinas, the country's largest network with about ten marinas under management including Cabarita Point and Rushcutters Bay in Sydney, The Spit on Sydney's lower north shore, Akuna Bay in Ku-ring-gai Chase, Pittwater on the northern beaches, Nelson Bay in Port Stephens, the Cairns marina in Far North Queensland, Trinity Point on Lake Macquarie, and the Sunshine Coast facility on Queensland's tourist coast. The d'Albora network is the single largest portfolio buyer of HVAC infrastructure in Australian marinas — a clubhouse rebuild or dry stack expansion in the d'Albora portfolio is a recurring 18-month tender cycle.

The yacht club estate that runs alongside the commercial marinas includes the Royal Sydney Yacht Squadron at Kirribilli on Sydney Harbour, the Cruising Yacht Club of Australia (CYCA) at Rushcutters Bay (host of the Sydney to Hobart blue-water race), the Royal Prince Alfred Yacht Club at Newport on Pittwater, the Royal Yacht Club of Tasmania at Hobart, the Royal Melbourne Yacht Squadron at St Kilda on Port Phillip, the Royal Brighton Yacht Club on Port Phillip's eastern shore, the Royal Queensland Yacht Squadron at Manly in Brisbane, the Royal Perth Yacht Club at Crawley on the Swan River, and the Hamilton Island Yacht Club in the Whitsundays. These are member-owned hospitality operations with clubhouse HVAC standards equivalent to a 4-star hotel.

The Queensland tourism coast adds Sanctuary Cove Marine on the Gold Coast, Marina Mirage at Main Beach (Gold Coast), Hope Harbour Marina at Hope Island, Mooloolaba Marina on the Sunshine Coast, the Cairns Marlin Marina in Far North Queensland, and the smaller but commercially significant Empire Marina at Bobbin Head in northern Sydney and Bermagui Fishermen's Co-op Marina on the New South Wales south coast. Commercial industrial-port marine operators include the Beechworth Group in the workboat and dive support segment and MMA Offshore for offshore vessel services. Charter and tourism operators that anchor large parts of the Whitsundays and Sydney Harbour visitor economy include Cruise Whitsundays, Sealink and Captain Cook Cruises — each operating fleets that require berthing infrastructure with on-shore amenity and a service workshop.

The relevance for HVAC ductwork procurement is that the buyer profile is split. The clubhouse renovation is typically a hospitality fit-out under a club committee, the dry stack and workshop expansion is a marina operator capital project, and the fueling station rebuild is a compliance-driven refit triggered by AS 1940 and AS/NZS 60079 inspection cycles. The duct specification has to satisfy all three buyers under one technical narrative, and the SBKJ engineering brief is normally written to land cleanly with whichever party is the principal contractor on a given package.

Zoning the marina precinct — nine HVAC zones in one project

The first hour of any marina HVAC specification meeting is spent agreeing the zoning. SBKJ engineers carry a standard nine-zone breakdown that maps cleanly to AS 1668.2 occupancy categories and AS/NZS 60079 hazardous area classification. Every duct decision flows from this breakdown.

Zone 1 — Clubhouse public spaces. Lounge, bar, dining room, member library, foyer and arrival. Hospitality-grade HVAC at 22–24°C with mechanical cooling rated for peak summer regatta-day occupancy. Galvanised TDF ductwork to AS/NZS 4254 is acceptable here because the envelope is positively pressurised and excludes salt aerosol. Acoustic target NC-35.

Zone 2 — Member function rooms. Presentation nights, weddings, corporate hire, after-race dinners. 6–8 air changes per hour (ACH) under AS 1668.2 hospitality occupancy, with ventilation rate Vp at the upper end of 8–10 L/s per person because the room is regularly operating at peak occupancy. Acoustic target NC-35 to NC-40 depending on whether live music is part of the brief.

Zone 3 — Member toilets and change rooms. 25 L/s per water closet under AS 1668.2 specific extract rates, plus a moisture and salt aerosol management strategy because members walk in from the dock in wet sailing gear and rinse off in showers that produce chloride-laden steam. SBKJ specifies 316L stainless or aluminium extract duct inside the change rooms to handle the corrosive condensate.

Zone 4 — Race control and weather station. Working room with radio communications, weather data feeds, course management. Precision climate at 22°C ± 1°C, NC-30 acoustic, redundant cooling because a race control failure during a Sydney-to-Hobart start is a publication-class incident.

Zone 5 — Retail chandlery. Ship-store retail with sails, rigging hardware, charts, clothing and member apparel. 22–24°C ambient retail standard, modest ventilation rate, acoustic target NC-40. The chandlery often shares an external wall with the dry stack hall, which dictates a pressure-separation strategy.

Zone 6 — Hardstand and dry stack storage. High-bay warehouse with stacker forklifts retrieving trailerable boats up to 12 metres. Natural cross-ventilation through louvred openings, supplemented by mechanical extract sized for boat engine warm-up (CO and unburned hydrocarbons), battery charging (hydrogen dispersion), and bilge water evaporation. Duct material is marine-grade aluminium or 316L stainless because the indoor air is brackish.

Zone 7 — Refit and service workshop. Composite repair benches, engine service bays, paint touch-up booth, hardware and rigging shop. Composite repair styrene exhaust is cross-referenced from the boat-building and yacht-marine manufacturing guide. Engine service bays need oil mist and bilge-water-vapour capture. Paint touch-up booths follow NFPA 33 spray booth envelope ventilation. NC-50 acoustic is acceptable for workshop ambient.

Zone 8 — Fueling station and engine bay. Marine fueling at the jetty head (petrol and diesel) and any on-shore LPG cylinder fill or storage. AS/NZS 60079 hazardous area Zone 1 around the fuel pumps and dispenser, Zone 2 around the vent risers and over-fill points. AS 1940 governs the bulk tank vapour management. All extract duct is fully welded 316L stainless with bonded earth straps on every flange.

Zone 9 — Outdoor equipment, plant rooms and pump houses. Generator rooms, fire pump rooms, sprinkler tanks, treatment plant for grey water and bilge water, and the breakwater bilge pumping stations. Marine-grade aluminium or 316L stainless extract on all generator and pump room exhaust, and any combustion air intake needs salt-aerosol filtration ahead of the duct work.

AS 1668.2 ventilation — clubhouse, function rooms, amenities

AS 1668.2:2012 (the use of ventilation and airconditioning in buildings, mechanical ventilation in buildings) is the single most important code in the marina HVAC specification. Its core requirement is a mechanical ventilation rate Vp expressed in litres per second per person, with values that vary from 5 L/s/person for a low-density office to 12 L/s/person for a high-density bar or a function room with smoking permitted historically (though smoking is now prohibited in licensed venues so the design point sits around 10 L/s/person for high-density function spaces).

For yacht club clubhouses, the design points SBKJ uses are:

• Lounge, library, quiet bar. 8 L/s/person at a peak occupancy of 0.5 persons per m². This is the everyday clubhouse experience and the duct sizing is comfortable, with low face velocity at the diffuser to hit NC-35.
• Dining room. 8–10 L/s/person at peak occupancy of 1.0 persons per m² for a sit-down dinner format. The kitchen exhaust is on a separate canopy hood and grease duct schedule under AS 1668.1.
• Main bar with standing crowd. 10 L/s/person at peak occupancy of 1.2 persons per m². This is the design point that drives the clubhouse air-handler size on regatta presentation nights when 200 members are standing for the prize giving.
• Function room. 10 L/s/person at peak occupancy of 1.0 persons per m², with a target 6–8 air changes per hour to maintain CO₂ below 1,000 ppm during a four-hour event. This is the second-highest single-zone load in the project after the kitchen.
• Member toilets. 25 L/s per WC under AS 1668.2 specific extract, with the extract duct sized to maintain negative pressure relative to the lobby. SBKJ specifies a 316L extract duct in this zone because the chloride-laden shower steam from change rooms attacks galvanised duct from inside out.
• Change rooms and dryers. 10 L/s per m² floor area where wet sailing gear is being dried, with a heated supply air plenum to prevent condensation on the duct exterior.

The peak-occupancy nature of yacht club operations is what trips many designers. A club that serves 80 covers a night for routine member dining will see 250 members on a presentation night, 400 at the season-opening regatta, and 600 at a 12-hour invitational over a long weekend. The duct system has to handle the peak without recirculating CO₂ to the point where members feel the air go stale, because the perceived-comfort standard at a club is set by the most experienced members who travel internationally and know what good hospitality HVAC feels like. SBKJ designs for the 95th percentile event load, not the average day.

AS/NZS 60079 hazardous area — the fueling station and LPG cylinder store

AS/NZS 60079.10.1 is the explosive atmospheres standard for the classification of areas — Explosive gas atmospheres. At a marina fueling station the standard mandates a hazardous area drawing that maps Zone 0, 1 and 2 envelopes around every point where flammable vapour can exist under normal or fault conditions.

The typical marina fueling station has the following hazardous area envelopes:

• Zone 0 — continuous presence of flammable vapour. Inside the bulk fuel tank, inside the vapour recovery line, inside the dispenser internals during fuelling. No HVAC equipment is permitted inside Zone 0.
• Zone 1 — flammable vapour present in normal operation. Around the dispenser nozzle and hose connection, within a 1.0 m radius of the bulk tank vent riser, inside the LPG cylinder fill bay during decanting. HVAC equipment in Zone 1 must be Ex-rated to Ex e, Ex d or Ex p protection levels and the duct must be conductive, earthed and continuity-tested.
• Zone 2 — flammable vapour present only in fault conditions. Around the dispenser island within 3 m of the nozzle outlet, around the bulk tank vent within 3 m, around the LPG cylinder storage cage. HVAC equipment in Zone 2 must be Ex n or higher protection level and ventilation rates must be sized to dilute any escaping vapour to less than 25% of the lower explosive limit (LEL).

The companion standard AS 1940 (the storage and handling of flammable and combustible liquids) sets the minimum ventilation rate for the bulk tank vent, the decanting bay and the LPG cylinder store. The headline numbers are 6 air changes per hour minimum for a covered decanting area and natural cross-ventilation with maximum free-area louvre openings for an open-sided fuel canopy. The vapour recovery system on the bulk tank breather is a dedicated dry seal that returns vapour to the tank during fuelling rather than venting to atmosphere.

For duct material selection, SBKJ specifies 316L stainless steel for any duct that passes through Zone 1 or Zone 2, fully welded with TIG seam welding rather than Pittsburgh lock, and every flange earth-bonded to a station equipotential bond. The reason is twofold — the duct material has to survive the chloride-rich marine atmosphere outside the fueling envelope, and the duct interior has to survive the petrol and diesel vapour and the trace lead and sulphur compounds that condense on cool duct surfaces over years of operation. Galvanised duct in a fueling station extract corrodes from the inside in 18–24 months.

ISO 9223 atmospheric corrosivity — why C5-M kills galvanised duct

ISO 9223 (Corrosion of metals and alloys — Corrosivity of atmospheres — Classification, determination and estimation) is the international standard that classifies outdoor atmospheres on a scale of C1 (very low) through C5 (very high), with the suffix M for marine, I for industrial, T for tropical and so on. The Australian coastal atmosphere within 500 m of mean high water sits at C5-M, which is the most aggressive routine atmosphere in the Australian environment outside of an industrial fence line.

The mechanism that drives C5-M corrosion of galvanised steel is chloride attack. Salt spray and aerosol from breaking surf and wind-driven ocean evaporation lands on duct surfaces and dries, leaving a layer of sodium and magnesium chloride that becomes hygroscopic — it absorbs moisture from the air at relative humidity above 60% and forms a saturated chloride brine on the duct surface. This brine penetrates the zinc layer of galvanised duct, attacks the zinc, exposes the underlying steel and drives rust formation at rates of 25–80 µm per year. A standard 275 g/m² galvanised duct has a zinc layer thickness of about 19 µm per side, which is consumed in 6–12 months in a true C5-M environment. After the zinc is consumed the steel itself rusts through.

The practical implication for marina duct is that galvanised duct has a 3–5 year service life in any duct run that sees direct marine aerosol exposure — outdoor risers, hardstand and dry stack ventilation, fueling station extract, refit workshop natural ventilation, and any duct that passes through an open-sided structure within 200 m of the breakwater. Inside the conditioned clubhouse envelope, where the air handler filters out salt aerosol and the building is positively pressurised, galvanised duct lasts the design life of the building (25–30 years).

The material selection rules SBKJ applies on every marina project are:

• 316L stainless steel duct for outdoor and semi-outdoor runs, hazardous area extract at the fueling station, member toilet and change room extract where chloride condensate is in the duct interior, and any duct that passes through a salt-aerosol-exposed cavity. 316L is the molybdenum-bearing grade that resists chloride pitting; 304 stainless does not, and is not specified for marine duty.
• Marine-grade aluminium 5052 or 5754 for outdoor ductwork where weight is a structural consideration (rooftop riser stacks, high-bay dry stack ducts) and where the duct is not in contact with fuel vapour or paint solvents. Aluminium is lighter, cheaper than 316L and entirely suited to C5-M exterior service.
• Galvanised steel duct only inside a fully conditioned clubhouse envelope with positive pressurisation and salt-aerosol filtration on the outside air intake. Acceptable for chandlery retail, function rooms, dining room, foyer and back-of-house dry storage. Not acceptable for any toilet or change room, any kitchen exhaust, any extract that handles chloride aerosol from inside the duct.

Yacht club clubhouse — hospitality-grade HVAC inside a coastal envelope

The clubhouse is the yacht club's hospitality brand. Members and guests judge the club by the lounge temperature, the bar acoustic, the dining room air freshness and the foyer first impression. The HVAC specification is therefore aligned with 4-star hotel hospitality standards, not with an office building or a public-school assembly hall.

The temperature target is 22–24°C operating with humidity controlled between 40–60% relative humidity. The cooling load profile is dominated by solar gain on the harbour-facing glazing and by the peak-occupancy crowd load on regatta and presentation nights. A clubhouse rated for 200 standing members on Sydney-to-Hobart start day needs a cooling capacity 50–80% greater than a clubhouse with the same floor area in a non-event-driven hospitality operation. SBKJ sizes the air handler to handle the 95th percentile event, with VFD-driven supply fan modulation so the system runs efficiently on routine days.

The acoustic target is NC-35 across lounge, bar, dining and library. NC-35 means the duct cross-section is sized for face velocity at the diffuser of 2.5–3.0 m/s, with internal acoustic lining (25 mm fibreglass with perforated metal cover) on the supply air ducts upstream of the dining room and lounge diffusers. The kitchen exhaust is on a separate riser and acoustically isolated from the dining room ceiling cavity.

The duct material is galvanised TDF to AS/NZS 4254 because the clubhouse is positively pressurised and the outside air intake is salt-aerosol-filtered. Pittsburgh lock seam construction with TDF transverse joints (Transverse Duct Flange) is the SBKJ standard, fabricated on the SBAL-V auto duct production line. Where acoustic NC-35 is the target, internal duct lining is included in the prefab scope.

The supply air diffuser strategy in a yacht club clubhouse is normally a mix of linear slot diffusers along the perimeter glazing (to manage solar gain) and round ceiling diffusers in the centre of the space (to handle occupancy load). Return air is typically through a high-level ceiling void grille or a low-level chair-rail return. The duct designer's first job is to keep the supply air path away from the bar and dining areas where conversation acoustic is most sensitive.

Function room — peak-occupancy hospitality

The member function room is the most dynamic HVAC zone in the clubhouse. A typical 200 m² function room runs at 20 people for a routine committee meeting, 80 people for a sit-down dinner, 200 people for a presentation night and 250 people for a regatta after-party — a 12.5× range in occupancy load.

The design points SBKJ uses are:

• Ventilation rate. 10 L/s per person at peak occupancy of 1.0 persons per m² gives a total fresh-air requirement of 2,000 L/s (200 m² × 1.0 person × 10 L/s) for a 200 m² function room. That corresponds to about 7.2 ACH at a 1,000 m³ room volume, which sits at the upper end of the AS 1668.2 6–8 ACH band for hospitality occupancies.
• CO₂ control. CO₂ sensors in the return air duct modulate supply fan speed and outside air damper position to maintain CO₂ below 1,000 ppm during the event. On a quiet committee meeting the system runs at minimum airflow; on a presentation night it runs at peak.
• Temperature setpoint. 22°C ± 1°C during the event, with a pre-event purge cycle to bring the room to 21°C before the doors open. The crowd heat load brings the room to setpoint within 20 minutes of the start.
• Acoustic NC-35 to NC-40. NC-35 for a sit-down dinner, NC-40 acceptable for a live-music event where the room ambient is dominated by the band's PA. Duct attenuators on the supply riser if the function room shares a riser with the dining room.

The duct material is galvanised TDF inside the conditioned envelope, with stainless steel at the entry and exit of any cool-room or external supply air shaft to handle condensate.

Hardstand and dry stack storage — high-bay industrial ventilation

The dry stack hall is the marina's largest single building by floor area on most modern precincts — a 600-berth marina with a 40% dry stack ratio has a 240-vessel storage hall of typically 4,000–6,000 m² with eaves height 12–18 m and rack heights 4–6 stories. The HVAC strategy is fundamentally different from the clubhouse: this is high-bay industrial ventilation, not hospitality.

The primary ventilation strategy is natural cross-ventilation through louvred openings at high level (warm air buoyancy outlet) and low level (cool air inlet) on opposite long elevations of the building. Calculated free area is typically 1–2% of floor area each side, which gives a stack-driven ventilation rate of 3–5 ACH on a still day rising to 8–15 ACH in a 10-knot sea breeze.

The supplementary mechanical extract is sized to handle three event-driven loads:

• Boat engine warm-up. Stack staff regularly start outboard or inboard engines while boats are still on the rack for fault diagnosis. CO and unburned hydrocarbons need to be extracted from the rack aisle at 8–10 ACH local extract for 15–30 minutes per event.
• Battery charging hydrogen dispersion. Lead-acid battery charging stations vent hydrogen. AS 4775 and AS/NZS 60079 set hydrogen dispersion as a hazardous-area concern; the practical rule is 6 ACH minimum in the battery charging zone to keep hydrogen below 1% by volume (25% of LEL).
• Bilge water evaporation. Boats arriving from a wet sail or a salt-water flush carry several litres of bilge water that evaporates over 24–48 hours in the rack. The evaporated chloride aerosol is what makes the dry stack air corrosive to duct interiors — and is the reason galvanised duct is not specified inside the dry stack hall.

The duct material for supplementary mechanical extract inside the dry stack hall is marine-grade aluminium (5052 or 5754) or 316L stainless steel. The galvanised duct option that is acceptable inside the clubhouse is not acceptable here because the air inside the dry stack hall is brackish, salt-laden, and hot in summer. Internal duct corrosion in a galvanised dry stack duct produces zinc oxide flakes that travel down the duct, contaminate the extract fan and shorten the fan service life to 3–4 years.

Refit and service workshop — composite, engine, paint

The refit and service workshop is the marina's most diverse HVAC zone after the clubhouse. A 600-berth marina with full-service refit typically has 1,500–2,500 m² of workshop floor split between composite repair, engine service, paint touch-up, hardware fabrication, sail loft and a member storage area for off-season gear.

Composite repair area. Styrene and methyl ethyl ketone peroxide (MEKP) exhaust from gelcoat and laminate repair work is identical to a boatyard environment — see the SBKJ boat building and yacht marine manufacturing HVAC duct guide for the full specification, which covers styrene capture at 8 ACH local extract through a closed booth, activated carbon filtration or thermal oxidiser exhaust treatment, and AS 1940 storage of resin and peroxide. Duct material is 316L stainless because the styrene-rich extract atmosphere attacks aluminium over time.

Engine service bay. Inboard and outboard engine service produces oil mist (from engine internal blow-by), bilge water vapour (when an engine is removed and the engine bay is power-washed), and hydrocarbon fumes from fuel system service. SBKJ specifies a local extract canopy hood over each engine service bay rated for 1.5 m/s capture velocity at the source, ducted to a dedicated extract fan that discharges above the workshop roof. The extract duct is marine-grade aluminium because oil mist attacks zinc rapidly.

Paint touch-up booth. A boat refit paint booth follows NFPA 33 (Spray Application Using Flammable or Combustible Materials), which dictates envelope ventilation at 0.51 m/s downdraft for a downdraft booth or 0.31 m/s crossdraft for a crossdraft booth, with all electrical and HVAC components Ex-rated for the booth Zone 1 envelope. Duct is fully welded 316L stainless with bonded earth straps; the duct interior accumulates paint overspray and is cleaned on a 6-month cycle. Make-up air is heated and dehumidified to keep the booth operating in winter and summer.

Hardware fabrication shop. Welding, grinding and metalwork on stainless steel rigging hardware. Local extract at each welding bench with 3 ACH general workshop ventilation to keep the floor air clean. NC-50 acoustic acceptable.

Sail loft. Sail repair and sailmaking is essentially a sewing operation with industrial-scale machines and large floor footprint. 22–24°C ambient with 6 ACH general ventilation; acoustic NC-40 because conversation is part of the work. Duct material is galvanised inside the conditioned envelope.

Fueling station — Ex-rated, vapour recovery, stainless duct

The marina fueling station is the highest-consequence HVAC zone in the precinct. A petrol vapour ignition near the jetty fueling head is a national-incident-level event, and the engineering controls — AS/NZS 60079 hazardous area protection, AS 1940 vapour recovery, AS 1657 fixed platform access, AS 4801 OHS management — are all tested by routine compliance audits.

The SBKJ fueling station HVAC specification has the following non-negotiables:

• Ex-rated fans on all extract. Extract fans serving the dispenser canopy, the bulk tank vent envelope, the decanting bay and the LPG cylinder store are Ex-rated to the appropriate zone (Ex d or Ex p for Zone 1, Ex n or higher for Zone 2). Fan motor manufacturer is selected from the SBKJ approved-vendor list and the IECEx certificate is provided in the project handover pack.
• Fully welded 316L stainless duct. Every duct run that passes through Zone 1 or Zone 2 is fully welded with TIG seam welding rather than Pittsburgh lock seam, because Pittsburgh seams are a known leakage path under pressure pulsation. Flanges are 316L with PTFE gaskets and stainless fasteners.
• Earth-bonded continuity. Every duct flange has an earth strap bonded to the station equipotential earth grid, and continuity is tested at commissioning and on the annual hazardous area inspection cycle. The reason is to prevent any electrostatic discharge from vapour-laden duct surfaces igniting petrol vapour.
• AS 1940 vapour recovery. The bulk fuel tank vent is fitted with a vapour recovery system (Stage 1 vapour recovery during tanker offload, Stage 2 vapour recovery during nozzle dispensing) that returns vapour to the bulk tank rather than venting to atmosphere. The vent breather is a dry-seal pressure/vacuum valve rated for the tank.
• Dispenser canopy ventilation. The canopy over the fueling jetty is naturally ventilated with maximum free-area louvres on three sides, supplemented by mechanical extract on a manual switch that operates during refuelling. The intent is to dilute any escaping vapour to less than 25% LEL within 10 seconds of release.
• LPG cylinder store. If the marina sells gas bottles for member yacht galleys, the cylinder storage cage is hazardous Zone 2 in the upright position and Zone 1 around a leaking cylinder. Storage cage has high-level and low-level natural ventilation, and the discharge from any extract fan rises through a dedicated stack to roof level.

Retail chandlery — ship-store hospitality

The chandlery is the marina's retail showroom — sails, rigging hardware, electronics, charts, navigation guides, foul-weather gear, member apparel and gifts. The HVAC standard is retail ambient at 22–24°C with modest ventilation. The acoustic target is NC-40, which is generous for retail because the chandlery is typically not a high-conversation environment.

The duct material is galvanised TDF inside the conditioned envelope because the chandlery shares the clubhouse air-handling system and is positively pressurised against the dry stack hall. The pressure relationship matters — if the chandlery is at neutral pressure or negative pressure relative to the dry stack, brackish air infiltrates through the connecting door and corrodes the retail fitout, damages chart paper and discolours leather goods. SBKJ specifies a 15–25 Pa positive pressure differential from chandlery to dry stack as part of the air-balance commissioning brief.

Member toilets and change rooms — chloride aerosol management

The member toilet and change room block at a yacht club is where members rinse off after a sail, change out of wet kit, shower and use the toilets. The air inside these rooms is chloride-laden steam — and is the second most aggressive HVAC environment in the precinct after the fueling station extract.

The SBKJ specification for this zone is:

• 25 L/s per WC. AS 1668.2 specific extract rate for water closets, ducted to a dedicated extract fan that discharges above the roof at a location at least 6 m from any building outside air intake.
• 10 L/s per m² floor area in change rooms. Where wet gear is being dried and showers are in operation, the change room extract rate is set high to keep relative humidity below 70%.
• 316L stainless or marine aluminium extract duct. The chloride-laden condensate inside the duct attacks galvanised duct from inside out. SBKJ has replaced galvanised toilet extract ductwork at marinas with 5-year-old buildings — the duct interior was a salt-rust mess. Specifying 316L upfront is cheaper than retrofitting in year 6.
• Negative pressure relative to clubhouse. 10–20 Pa negative pressure differential to prevent odour and humidity transfer to the lounge and dining areas.
• Heated supply air in winter. Change room supply air is heated to 24°C in winter so wet members don't experience a cold-air discomfort moment getting changed.

Race control and weather station — precision climate

Race control is the operational nerve centre of every active yacht club during a regatta. The room runs radio communications to fleet vessels, weather feeds from the Bureau of Meteorology and local sensor stations, course management software, video feeds from the start line cameras, and the official race timer and scoring system. A failure here during the start of an offshore race is a national-news event.

The HVAC specification is:

• 22°C ± 1°C precision. Operator comfort is critical for a 12-hour race-day shift, and the electronics generate concentrated heat load that needs precision control.
• NC-30 acoustic. Below the clubhouse standard because radio comms have to be clearly audible. Duct sizing keeps face velocity at the diffuser below 2.0 m/s.
• Redundant cooling. Two independent split or chilled-water systems sized at 60% capacity each. Failure of one allows continued operation while the second is being serviced.
• UPS-backed ventilation fan. The supply fan and the equipment-room extract fan are backed by the same UPS as the radio and computing equipment, so a 30-second mains glitch doesn't drop the room temperature control.
• Galvanised duct inside the clubhouse envelope is acceptable because race control is positively pressurised against the outside environment.

SBKJ machine configuration for marina projects

SBKJ's standard machine recommendation for an Australian marina project is the SBAL-V auto duct production line configured with two specific options:

• Stainless steel 316L coil handling. The decoiler, leveller, beading station and Pittsburgh lock-former are specified for stainless coil 0.8–1.5 mm thickness. Tooling is hardened to handle the work-hardening behaviour of stainless. A separate aluminium coil handling configuration is available where the project duct is split between stainless (hazardous area, toilet extract) and aluminium (dry stack, hardstand).
• TIG seam welder option. For fully welded outdoor and hazardous-area duct runs, the SBAL-V is supplied with an inline TIG seam welder that replaces the Pittsburgh lock seam on selected ducts. TIG welding produces a continuous gas-tight seam suitable for AS/NZS 60079 hazardous area service and for ISO 9223 C5-M outdoor exposure.

A 600-berth marina with full clubhouse, function rooms, refit workshop, fueling station and dry stack typically needs 1,200–1,800 m² of total duct surface area split roughly:

• 60% galvanised TDF for the clubhouse, function rooms, chandlery, sail loft. Inside the conditioned envelope.
• 25% marine aluminium for dry stack, hardstand, refit workshop general ventilation. Brackish but not hazardous.
• 15% fully welded 316L stainless for fueling station extract, toilet and change room extract, composite repair extract, hazardous area duct. The high-consequence and high-corrosion service.

The SBAL-V machine produces the duct in-house at the fabricator's shop, which means the project schedule is decoupled from a single-source duct supplier and the quality is consistent across the three material types. SBKJ supplies the machine, the tooling, the commissioning support and the operator training; the fabricator runs the production line and delivers the duct to site against the construction schedule.

Acoustic targets across the marina precinct

The acoustic specification for an Australian yacht club and marina sits in a tighter band than most commercial buildings. The clubhouse hospitality areas need quiet enough HVAC that members can have a conversation, and the race control and weather station need quiet enough HVAC that radio communications are clearly audible.

The SBKJ acoustic schedule is:

• NC-25 to NC-30 — Race control, weather station, committee room, member library. Working spaces with critical communications. Duct sized for very low diffuser face velocity (1.5–2.0 m/s), internal acoustic lining, possibly inline duct attenuators on the supply branch.
• NC-35 — Lounge, bar, dining, foyer. Clubhouse hospitality standard. Face velocity 2.5–3.0 m/s, internal lining on supply.
• NC-35 to NC-40 — Function room. Depends on event format. NC-35 for sit-down dinners, NC-40 for live music.
• NC-40 — Chandlery, sail loft, member amenities. Modest acoustic, no lining.
• NC-45 to NC-50 — Refit workshop, dry stack hall. Industrial workspace where the HVAC sits below the ambient noise floor anyway. No lining.

Australian marina project pipeline — where the duct demand is

The Australian marina industry capital expenditure cycle over the next decade is dominated by three drivers — climate-resilience upgrades to coastal infrastructure, the growth of the dry stack model on the east coast, and the continued upgrading of yacht club clubhouses to a hospitality standard that retains affluent members in a competitive leisure market.

The d'Albora Marinas network — Cabarita, The Spit, Akuna Bay, Pittwater, Nelson Bay, Rushcutters Bay, Cairns, Trinity Point on Lake Macquarie, the Sunshine Coast facility — is the largest single buyer of HVAC infrastructure in the Australian marina sector. A clubhouse rebuild in this portfolio is a 12–18 month tender cycle with predictable specification requirements. SBKJ supplies duct machinery to fabricators who bid into the d'Albora portfolio.

The royal yacht squadron estate — Royal Sydney Yacht Squadron at Kirribilli, Cruising Yacht Club of Australia at Rushcutters Bay, Royal Prince Alfred at Newport, Royal Yacht Club of Tasmania at Hobart, Royal Melbourne Yacht Squadron at St Kilda, Royal Brighton Yacht Club, Royal Queensland Yacht Squadron at Manly Brisbane, Royal Perth Yacht Club at Crawley, Hamilton Island Yacht Club — runs a slower capital cycle of 20–30 year clubhouse renovations. The current renovation wave is upgrading 1960s and 1970s clubhouse fitouts to 4-star hospitality standards.

The Queensland tourism coast — Sanctuary Cove Marine, Marina Mirage at Main Beach, Hope Harbour at Hope Island, Mooloolaba Marina, Cairns Marlin Marina — is the highest-growth segment in dry stack capacity and is driving demand for marine-grade aluminium and 316L stainless duct in the dry stack, fueling and engine bay zones.

The NSW south coast and Tasmanian operations — Empire Marina at Bobbin Head, Bermagui Fishermen's Co-op Marina, the Royal Yacht Club of Tasmania at Hobart — service a different commercial mix dominated by fishing fleet support, dive support, charter and recreational marinas with smaller per-project HVAC scope but more frequent refit cycles.

The commercial industrial marine operators — Beechworth Group in workboat and dive support, MMA Offshore in offshore vessel services — buy HVAC at the wharf and operations centre level rather than at the recreational clubhouse level, and the specification leans heavily on AS/NZS 60079 hazardous area and AS 1940 flammable liquid handling because the operations involve daily fuel handling.

The charter and tourism operators — Cruise Whitsundays, Sealink, Captain Cook Cruises — operate ferry and charter fleets that require berthing infrastructure with substantial on-shore amenity and a service workshop. The HVAC scope is split between a hospitality-style ferry terminal (closer to a small airport terminal in specification) and a refit workshop closer to the d'Albora model.

Common HVAC mistakes on marina projects

Working through 30 years of marina HVAC retrofits, the SBKJ engineering team sees the same six mistakes repeated across the industry. The cost of avoiding them at design stage is a few hours of engineering time; the cost of fixing them in year 4 is a partial system rebuild.

Mistake 1 — Galvanised duct outside the clubhouse envelope. A duct run that crosses an external wall, sits in a roof void with marine aerosol infiltration, or passes through a hardstand canopy will fail in 3–5 years if it is galvanised. The cost premium of 316L or marine aluminium at design stage is 30–60%. The cost of replacing the duct in year 4 is 250–400% of the original install, plus the disruption to clubhouse operations.

Mistake 2 — Under-sized function room ventilation. Designing the function room to a 4-ACH office standard means CO₂ climbs above 1,500 ppm by the third hour of a regatta presentation night and the members notice the stale air. The remedy is to design at 6–8 ACH from day one — the duct cross-section is 30–50% bigger but the air-handler operating cost is the same on a quiet day because VFD-driven supply fan modulation keeps the average load down.

Mistake 3 — No hazardous area drawing at the fueling station. A fueling station built without an AS/NZS 60079 hazardous area drawing is a future compliance liability. The hazardous area inspector at the annual cycle will require remediation, and the remediation cost is typically 5–10× the cost of doing the drawing and specification at design stage.

Mistake 4 — Galvanised toilet and change room extract duct. The chloride condensate inside the duct attacks the zinc from the inside out. The duct interior is invisible from the building, so the failure is not detected until duct sections start collapsing or the extract fan is contaminated with rust flakes. SBKJ specifies 316L stainless for all toilet and change room extract.

Mistake 5 — Acoustic specification missed at the race control room. The HVAC plant is sized correctly but the duct face velocity at the race control diffuser is 4.0 m/s rather than 1.5 m/s, and the room ambient is NC-40 rather than NC-30. The remedy is duct upsizing at design stage; retrofitting acoustic attenuators in a finished ceiling void is intrusive and expensive.

Mistake 6 — Single zone HVAC across clubhouse and dry stack. The clubhouse and dry stack are served from the same air-handler and the dry stack's brackish air mixes with the clubhouse supply air. The clubhouse interior corrodes — picture frames, electronics, leather furniture — at C5-M rates. The remedy is separate air-handling systems with positive pressure differential at the clubhouse and a negative pressure differential at the dry stack.

How SBKJ supports marina HVAC duct fabrication

SBKJ is the Australian-headquartered HVAC duct machinery brand of SBKJ Group, with the regional office in Box Hill North VIC. Our role on a marina project is to supply the fabrication machinery and the engineering brief that the fabricator uses to produce the project ductwork in 316L stainless, marine-grade aluminium and galvanised steel against the project AS 1668.2, AS/NZS 60079 and ISO 9223 specifications.

• SBAL-V auto duct production line configured for the project duct schedule — coil width, thickness, material grade, seam type, transverse joint. Single machine, three material types, one operator training pack.
• TIG seam welder option for fully welded duct on hazardous area and outdoor C5-M service.
• Engineering support for the project AS 1668.2 ventilation calculation, AS/NZS 60079 hazardous area review, ISO 9223 corrosivity zoning and the SBKJ duct schedule against the project drawings.
• Operator training for stainless and aluminium coil handling, TIG seam welder operation, and the QA inspection process for hazardous area duct.
• 10-year parts continuity commitment, with the Box Hill North VIC office providing English-speaking after-sales support.

Request an SBKJ marina duct schedule against your project →

FAQ

What ventilation rate does AS 1668.2 require for yacht club clubhouses?

AS 1668.2 sets Vp at 8–10 L/s per person for hospitality occupancies, with 25 L/s per WC for member toilets and 10 L/s per m² in change rooms. Function rooms target 6–8 ACH with CO₂ control below 1,000 ppm during peak events.

What duct material survives the marine C5-M atmosphere?

ISO 9223 C5-M chloride aerosol consumes the zinc layer of galvanised duct in 6–12 months and the duct itself in 3–5 years. Marine-grade aluminium (5052 or 5754) and 316L stainless steel are the only economically defensible choices for outdoor and semi-outdoor duct. Galvanised duct is acceptable only inside a positively pressurised, salt-aerosol-filtered clubhouse envelope.

How is the fueling station ducted under AS/NZS 60079?

Fully welded 316L stainless duct, Ex-rated fans, earth-bonded flanges, AS 1940 vapour recovery on the bulk tank vent. Zone 1 around the dispenser nozzle and tank vent within 1 m, Zone 2 within 3 m. SBKJ specifies TIG seam welding rather than Pittsburgh lock for hazardous area service.

What is the acoustic target for a yacht club race control room?

NC-30 or lower because radio communications, weather feeds and concentrated decision making demand a quiet ambient. Clubhouse hospitality areas sit at NC-35, function rooms NC-35 to NC-40, refit workshop NC-50.

What is the SBKJ recommended machine configuration for marina projects?

SBAL-V auto duct production line configured for stainless 316L or marine-grade aluminium coil, with the optional TIG seam welder for fully welded hazardous-area and outdoor C5-M duct. A 600-berth marina typically needs 1,200–1,800 m² of total duct split 60% galvanised (clubhouse interior), 25% marine aluminium (dry stack, workshop), 15% fully welded 316L (fueling, toilet extract, composite repair).