NCC 2019 Volume One
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Part F4 Light and ventilation
Performance Requirements
FP4.1 Natural lighting
Sufficient openings must be provided and distributed in a building, appropriate to the function or use of that part of the building so that natural light, when available, provides an average daylight factor of not less than 2%.
Application:
Application:
FP4.1 only applies to a Class 2, 3 or 9 building, or a Class 4 part of a building.
The Objective of this Part is to—
(a)
safeguard occupants from injury, illness or loss of amenity due to—
(i)
isolation from natural light; and
(ii)
lack of adequate artificial lighting; and
(b)
safeguard occupants from illness or loss of amenity due to lack of air freshness.
A space within a building used by occupants is to be provided with openings to admit natural light consistent with its function or use.
FF4.1 requires that a building space must have openings providing enough natural light for a room to fulfil its purpose.
A space within a building used by occupants is to be provided with artificial lighting consistent with its function or use which, when activated in the absence of suitable natural light, will enable safe movement.
A space used by occupants within a building is to be provided with adequate ventilation consistent with its function or use.
FF4.3 requires that a building space used by occupants must have ventilation that provides adequate air, so the room can fulfil its purpose. “Adequate air” includes both quantity and quality.
The building and its location may impose constraints on the quality of the ventilation air.
Example
Example
A building’s location may impose constraints on the quality of the ventilation air such as when the building is in a central business district. Here, even locating intakes at the highest point on the building could still draw in significant quantities of vehicle exhaust fumes. The air may not be totally “fresh”. None the less, efforts must be made to make sure the air is of adequate quality.
Ventilation standards are influenced by many factors, including:
- the number of people being provided with air;
- activities in the building which might lead to a build-up of toxic gases;
- climatic conditions; and
- the distribution of ventilation openings.
Some of the primary problems, which a ventilation system must attempt to overcome, include:
- excessive heat;
- excessive humidity; and
- offensive odours.
FP4.1 deals with natural light in Class 2, 3 or 9 building, or Class 4 parts of a building.
FP4.1 nominates a minimum average daylight factor for rooms provided with natural light. Note that Verification Method FV4.3 provides a method by which the average daylight factor may be calculated.
The level of natural light must be appropriate to the function of each part of the building (this differs from the FP4.2 requirement for artificial light).
FP4.2 Artificial lighting
Artificial lighting must be installed to provide an illuminance of not less than 20 lux appropriate to the function or use of the building to enable safe movement by occupants.
FP4.2 relates required lighting levels to the use of each part of the building. Unlike FP4.1 with regard to natural light, FP4.2 does not include the concept of even distribution.
The level of artificial light must be appropriate to the use of the building to enable safe movement by occupants (this differs from the FP4.1 requirement for natural light). For example, in a movie theatre a lower level of lighting may be appropriate while a movie is being screened, however at the beginning and end of the movie when occupants are entering and exiting the theatre the minimum lighting level of 20 lux may be appropriate.
FP4.3 Outdoor air supply
A space in a building used by occupants must be provided with means of ventilation with outdoor air which will maintain adequate air quality.
FP4.3 requires a building’s ventilation system to include for the supply of outdoor air.
FP4.4 Mechanical ventilation to control odours and contaminants
A mechanical air-handling system installed in a building must control—
(a)
the circulation of objectionable odours; and
(b)
the accumulation of harmful contamination by micro-organisms, pathogens and toxins.
Where a mechanical air-handling system is installed, FP4.4 requires it to achieve control with regard to the following:
- smells considered objectionable (including food, cooking and toilet odours); and
- the accumulation of germs, harmful microbes, other disease-causing agents, and poisons.
FP4.5 Disposal of contaminated air
Contaminated air must be disposed of in a manner which does not unduly create a nuisance or hazard to people in the building or other property.
FP4.5 requires that any contaminated air be disposed of so that it does not cause any nuisance or hazard to:
- occupants (of either the subject building, or any other building);
- people on neighbouring allotments; or
- people on a road.
Verification Methods
FV4.1 Verification of suitable indoor air quality
For a Class 2, 3, 5, 6, 9b or 9c building or Class 4 part of a building, compliance with FP4.3 and FP4.4(a) is verified when it is determined that the building under typical conditions in use is provided with sufficient ventilation with outdoor air such that contaminant levels do not exceed the limits specified in Table FV4.1.
Table FV4.1 Maximum contaminant limits for acceptable indoor air quality
|
Pollutant |
Averaging time |
Maximum air quality value |
|
Carbon dioxide, CO2 |
8 hours |
850 ppm Note 1 |
|
Carbon monoxide, CO |
15 minutes |
90 ppm |
|
Carbon monoxide, CO |
30 minutes |
50 ppm |
|
Carbon monoxide, CO |
1 hour |
25 ppm |
|
Carbon monoxide, CO |
8 hours |
10 ppm |
|
Formaldehyde, CH2O |
30 minutes |
0.1 mg/m3 |
|
Nitrogen dioxide, NO2 |
1 year |
40 μg/m3 (0.0197 ppm) Note 2 |
|
Nitrogen dioxide, NO2 |
1 hour |
200 μg/m3 (0.0987 ppm) |
|
Ozone, O3 |
8 hour, daily maximum |
100 μg/m3(0.0473 ppm) |
|
Particulate matter, PM2.5 |
1 year |
10 μg/m3 |
|
Particulate matter, PM2.5 |
24 hour (99th percentile) |
25 μg/m3 |
|
Particulate matter, PM10 |
1 year |
20 μg/m3 |
|
Particulate matter, PM10 |
24 hour (99th percentile) |
50 μg/m3 |
|
Total volatile organic compounds |
1 hour |
500 μg/m3 |
Notes to Table FV4.1 :
- Based on body odour metric (i.e. 450 ppm above ambient CO2 level of 400 ppm and demand control ventilation provisions in AS 1668.2).
- Based on pressure of 101.325 kPa and temperature of 25°C (i.e. the conversion is mg/m3 = ppm (molecular weight/24.4)).
FV4.1 is a means of verifying if a proposed ventilation system for a Class 2, 3, 4, 6, 9b or 9c building achieves the minimum level of ventilation required by FP4.3 and FP4.4(a).
It is not compulsory for a designer to use FV4.1. The designer has the choice of using:
- FV4.1 to verify that the proposal achieves FP4.3 and FP4.4(a);
- the Deemed-to-Satisfy Provisions of F4.5 to F4.9 and F4.12; or
- another means of verifying that FP4.3 and FP4.4(a) will be achieved.
If FV4.1 is used to verify compliance, it must be demonstrated that the building is sufficiently ventilated with outdoor air such that contaminant levels do not exceed the limits in Table FV4.1.
FV4.2 Verification of suitable indoor air quality for carparks
For a Class 7a building, compliance with FP4.3 and FP4.4(a) is verified when it is determined that the building is provided with sufficient ventilation with outdoor air such that carbon monoxide exposure levels do not exceed the limits specified in Table FV4.2.
Table FV4.2 Maximum carbon monoxide exposure for carparks
Concentration (ppm)
Total exposure duration per day
100
Not to be exceeded
90
15 minutes
60
1 hour
30
8 hours
Note to Table FV4.2: Various government work, health and safety regulations specify workplace exposure limits for airborne contaminants in the workplace.
FV4.2 is a means of verifying if a proposed ventilation system for a Class 7a building achieves the minimum level of ventilation required by FP4.3 and FP4.4(a).
It is not compulsory for a designer to use FV4.2. The designer has the choice of using:
- FV4.2 to verify that the proposal achieves FP4.3 and FP4.4(a);
- the Deemed-to-Satisfy Provisions of F4.11; or
- another means of verifying that FP4.3 and FP4.4(a) will be achieved.
If FV4.2 is used to verify compliance, it must be demonstrated that the building is sufficiently ventilated with outdoor air such that carbon monoxide exposure levels do not exceed the limits in Table FV4.2.
FV4.3 Verification of suitable provision of natural light
Compliance with FP4.1 is verified for the provision of natural light for—
(a)
habitable rooms of Class 2 buildings and Class 4 parts of buildings; and
(b)
bedrooms and dormitories of Class 3 buildings; and
(c)
rooms used for sleeping purposes in Class 9a and 9c buildings; and
(d)
general purpose classrooms in primary and secondary school and playrooms or the like for the use of children in an early childhood centre in Class 9b buildings,
when the average daylight factor for each window is determined in accordance with the following formula:
W = the net area of the light transmitting area of the window (m2); and
A = the total area of the internal wall, floor and ceiling surfaces (m2); and
T = the diffuse light transmittance of the window; and
θ = visible sky angle in degrees, measured in a vertical plane normal to and from the centre of the window, and
R = the area-weighted average reflectance of area A.
The average daylight factor (ADF) is used as the measure of the general illumination from outdoor natural light within a room. Where two or more windows in a room face different obstructions, or differ in transmittance, the ADF should be found separately for each window by adding the ADF for each window together to get the total ADF for the room.
W is the net area of the glazing panel (m2). This excludes the glazing frame and only includes the transparent or translucent elements.
A is the total area of the internal surfaces (m2). This includes the total area of the ceiling, floor and walls, including windows.
T is the diffuse light transmittance of the glazing. The measurement of light transmittance is specified in the Technical Protocols and Procedures Manual for Energy Rating of Fenestration Products of the Australian Fenestration Rating Council. Typical examples of light transmittance of glazing materials are given in the table below.
Typical light transmittance of glazing materials
Material
Diffuse light transmittance
Clear 6 mm glass
0.87
Tinted 6 mm glass (bronze)
0.50
Tinted 6 mm glass (grey)
0.44
Tinted 6 mm glass (green)
0.75
Strongly reflecting 6 mm glass
0.78
Double glazed unit (x2 6 mm clear glass)
0.76
θ is visible sky angle in degrees, measured in a vertical plane normal to the glass from the centre of the window (window reference point) as shown in the figure below. The determination of this angle should take into account objects such as shading projections, eaves, window reveals, fences, adjoining buildings, structures and the like.
Angle of visible sky
R is the area-weighted average reflectance area of the internal surfaces. Typical examples of reflectance of light values of materials are given below.
Typical reflectance of light values of materials
Material
Reflectance
Paving
0.20
Earth
0.20
Granite
0.20
Brickwork (red)
0.30
Concrete
0.40
Carpet (cream)
0.40
Carpet (deep colours)
0.10
Wood (unfinished pine)
0.20
Paint (white)
0.85
Paint (cream)
0.81
Paint (light grey)
0.68
Paint (mild grey)
0.45