NCC 2019 Volume Two
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Part 3.8.5 Ventilation

Part 3.8.5 Ventilation

Appropriate Performance Requirements

Appropriate Performance Requirements

Where an alternative ventilation system is proposed as a Performance Solution to that described in Part 3.8.5, that proposal must comply with—

  1. Performance RequirementP2.4.5; and
  2. Performance RequirementP2.4.7; and
  3. the relevant Performance Requirement determined in accordance with A2.2(3) and A2.4(3) as applicable.

Explanatory information:

Explanatory information:

The requirements of this Part are to be read in conjunction with the condensation management requirements in Part 3.8.7 and the air movement requirements in Part 3.12.4. However, it should be noted that Part 3.12.4 does not apply in all States and Territories.

Acceptable Construction Manual

3.8.5.0 Application

Except for an exhaust fan from a sanitary compartment, laundry, kitchen or bathroom, Performance Requirement P2.4.5 is satisfied for a mechanical ventilation system if it is installed in accordance with AS 1668.2.

Acceptable Construction Practice

3.8.5.1 Application

Compliance with this acceptable construction practice satisfies Performance Requirement P2.4.5 for ventilation.

3.8.5.2 Ventilation requirements

Ventilation must be provided to a habitable room, sanitary compartment, bathroom, shower room, laundry and any other room occupied by a person for any purpose by any of the following means:

(a)

Openings, windows, doors or other devices which can be opened—

(i)

with a ventilating area not less than 5% of the floor area of the room required to be ventilated; and

(ii)

open to—

(A)

a suitably sized court, or space open to the sky; or

(B)

an open verandah, carport, or the like; or

(C)

an adjoining room in accordance with (b).

Explanatory information:

Explanatory information:

The ventilating area of a window is measured as the size of the openable sash of the window. This is the case regardless of the type of window, i.e. whether it is an awning, casement or sliding window and irrespective of the restrictions on the openable sash.

(b)

Natural ventilation to a room may come through a window, opening, door or other device from an adjoining room (including an enclosed verandah) if—

(i)

the room to be ventilated or the adjoining room is not a sanitary compartment; and

(ii)

the window, opening, door or other device has a ventilating area of not less than 5% of the floor area of the room to be ventilated; and

(iii)

the adjoining room has a window, opening, door or other device with a ventilating area of not less than 5% of the combined floor areas of both rooms; and

(iv)

the ventilating areas specified may be reduced as appropriate if direct natural ventilation is provided from another source.

(See Figure 3.8.5.1)

Explanatory information:

Explanatory information:

3.8.5.2(b) permits a room's required ventilation to be "borrowed" from an adjoining room, i.e. an adjoining room's ventilation can be used to help make up the total amount of ventilation required.

The use of borrowed ventilation is acceptable if the provisions of 3.8.5.2(b) are applied to the subject room and to the total area of each relevant room.

Figure 3.8.5.1 Method of determining areas of openings for borrowed ventilation
v2_Fig3851_2005.svg
(c)

An exhaust fan or other means of mechanical ventilation may be used to ventilate a sanitary compartment, laundry, kitchen or bathroom, or where mechanical ventilation is provided in accordance with 3.8.5.3(b), provided contaminated air exhausts comply with 3.8.7.3.

3.8.5.3 Location of sanitary compartments

Sanitary compartments must not open directly into a kitchen or pantry unless—

(a)

access is by an airlock, hallway or other room, (see Figure 3.8.5.2); or

(b)

the sanitary compartment is provided with an exhaust fan or other means of mechanical exhaust ventilation.

Figure 3.8.5.2 Acceptable location of non mechanically ventilated sanitary compartment
v2_Fig3852_2005.svg