Mechanical Ventilation Building Codes & Rules

- Mechanical Ventilation: Tools™ simplifies the National Construction Code (NCC) with interactive graphics, including deemed to comply & best practices.

Central

Exhaust Fan

Manufacturer's Recommendation - -, -

Mechanical Ventilation^{Manufacturer's Recommendation - -, -}

Increases Oxygen level
Employs dilution & displacement mechanisms to maintain healthy air quality
Increases thermal comfort & reduces humidity
Hire Certified Professional to service Ventilation Systems, air sampling, & implement recommendations

Fresh Air

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Extraction Hood

Laundry

Bathroom

Central

Supply Fan

Central Supply &

Exhaust Fan

AS 1668.2:2012, 4.1

Carparking Ventilation^{AS 1668.2:2012, 4.1}

Reduces the possibility for serious health consequences from pollutants produced by combustion engines
Enclosure ventilation amount depends on
Type & quality of vehicles using the space
Vehicles' operating time
Occupants' time spent in the space

Manufacturer's Recommendation - -, -

Service & Maintenance^{Manufacturer's Recommendation - -, -}

Scheduled regular inspections according to AS/NZS 3666.2
Repairs or replaces damaged, defective, or malfunctioning components
Inadequate servicing & maintenance may lead to
Moisture,
Mould, &
Air pollutants

AS 1668.1:2015, 5.5.1

FRNSW Guideline for Impulse Fans in car parks Ver.01 , 5.1

Impulse Fans^{AS 1668.1:2015, 5.5.1FRNSW Guideline for Impulse Fans in car parks Ver.01 , 5.1}

Must be located in driveways & accessways
Not above parking spaces or,
Other high fire risks areas
Installed in between rows of Fire Protection Devices such sprinkler heads & smoke or heat detectors
Air jets shouldn't clash with the sprinkler heads' functions
Automatically shutdowns upon activation of Sprinkler System
Fire Fan Control Panel (FFCP) for fans manual control to assist fire brigade intervention if required

AS 4254.1:2012, 2.2

Flexible Duct Sealing^{AS 4254.1:2012, 2.2}

All sealing materials must be
Non-toxic
Water & oil resistant after curing
Air sealing with the use of
Mastic,
Adhesive tapes, or
Compatible combination of two
It has to be airtight with or without outer jacket or sleeve insulation

Stale Air

AS 4254.2:2012, 2.2.1

Rigid Duct Sealing^{AS 4254.2:2012, 2.2.1}

Air sealing with the use of
Mastics,
Adhesive tapes,
Gaskets or,
Compatible combinations
Continuous welding sealing

AS 4254.1:2012, 2.7

Compliance Markings^{AS 4254.1:2012, 2.7}

1m Labelling interval
≥ 10mm font height
Readable throughout duct's service life
With the following information
Compliance with AS 4254.1
R value or approx. nominal diameter
Manufacturer's name

Window Natural Ventilation - Taylor Commentary

Confirm specified airflow can be achieved eg trickle vents
RFI may need to be submitted to confirm an alternative solution
Assess other functionalities
Weatherproofing
Insect & vermin proofing
Noise esp. whistling in high winds

Balanced Ventilation

Swaps fresh air outside & stale air inside the building^[1]
May include a Heat Recovery Ventilator (HRV) or an Energy Recovery Ventilator (ERV)^[2]

Energy Recovery or Heat Recovery Ventilator Design Factors

NCC 2022 V1

Added system/s that minimizes energy loss to a Balanced Ventilation
Heat Recovery Ventilator (HRV)
Recommended for dry, cold climates
Energy Recovery Ventilator (ERV)
Recommended for moist, warm climates
Advantages
Reduces heating & cooling costs
Cost-effective in climates with extreme winters or summers
Disadvantages
Costs more to install than other ventilation systems
Requires more maintenance than other ventilation systems
May not be cost-effective in mild climates
Verify design with Certified Professional to know the right additional ventilation system on your property

Balanced Ventilation Design Factors

NCC 2022 V1

Two fans & two duct ventilation systems
Advantages
Appropriate for all climates
Disadvantages
Cost more to install & operate than other ventilation systems
Will not moderate or remove moisture from incoming air
Increases heating & cooling costs

Manufacturer's Recommendation - -, -

Swaps fresh air outside & stale air inside the building^{Manufacturer's Recommendation - -, -}
May include a Heat Recovery Ventilator (HRV) or an Energy Recovery Ventilator (ERV)^{Manufacturer's Recommendation - -, -}

Fire-stopping Penetrations

Exhaust-only Ventilation

Expels indoor contaminants^[1]
Most appropriate for colder climates^[2]

Exhaust-only Ventilation Design Factors

NCC 2022 V1

Advantages
Works well in cold climates
Depressurize air interior
Simple & inexpensive to install
Disadvantages
Rely in part on random air leakage
Causes moisture damage in warmer climates
Can cause higher heating & cooling costs
Contaminants may be drawn into the building such
Dust & moulds from crawlspace & attics
Fumes from carpark garage
Flue gasses fireplace or furnace

Manufacturer's Recommendation - -, -

Expels indoor contaminants^{Manufacturer's Recommendation - -, -}
Most appropriate for colder climates^{Manufacturer's Recommendation - -, -}

AS 4254.2:2012, 2.2.1

Seal Class Requirements^{AS 4254.2:2012, 2.2.1}

Class A
≥ 1000 Pa static pressure
For all transverse joints, longitudinal seams & duct wall penetrations
Class B
501 to 999 Pa static pressure
For all transverse joints & longitudinal seams
Class C
≤ 500 Pa static pressure
For transverse joints & longitudinal seams 50mm from ducts ends

Combination of Exhaust Systems

Exhaust systems should remain separate unless enclosures are similar in nature^[1]

Enclosures with Common Exhaust Systems

NCC 2022 V1

AS 1668.2:2012, 3.9

AS 1668.2:2012, Table 3.2

Crucial Factors^{AS 1668.2:2012, 3.9AS 1668.2:2012, Table 3.2}
Keep different exhaust systems separate to avoid contamination
Especially in cases involving chemical or hazardous exhausts
Similar types of enclosures can share an exhaust system
Airlocks & privacy locks do not require exhaust but allow airflow from adjacent areas
Table is a partial list of enclosure groupings, there could be other similar enclosures that may qualify for shared exhaust systems

AS 1668.2:2012, 3.9

Exhaust systems should remain separate unless enclosures are similar in nature^{AS 1668.2:2012, 3.9}

Fire Damper Types & Inspection

Supply-only Ventilation

Required for ≥ 27° C room temperature under normal conditions^[1]
Work best in hot & mixed climates^[2]

Supply-only Ventilation Design Factors

NCC 2022 V1

Advantages
Filters & minimises pollutants entering into the building
Prevents backdrafting of combustion gasses
Simple & inexpensive to install
Installed to high trafficable areas
Disadvantages
Does not modify or remove moisture from the make-up air
Cold air drafts in the winter
In-line duct heater is optional but costly
Cold winter leaks
Moisture condensation
Moulds & decay risks

AS 1668.2:2012, 2.9.1

Manufacturer's Recommendation - -, -

Required for ≥ 27° C room temperature under normal conditions^{AS 1668.2:2012, 2.9.1}
Work best in hot & mixed climates^{Manufacturer's Recommendation - -, -}