NCC 2019 Volume Two
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Part 3.12.4 Air movement

Part 3.12.4 Air movement

3.12.4 Application

This Part applies to a habitable room in a Class 1 building.

3.12.4.1 Air movement

(a)

Air movement must be provided to habitable rooms in accordance with Table 3.12.4.1.

(b)

Air movement required by (a) may be provided through an opening from an adjoining room (including an enclosed verandah) if—

(i)

the adjoining room is not a sanitary compartment; and

(ii)

the opening between the adjoining room and the habitable room complies with Table 3.12.4.1 as if it were a ventilation opening to the habitable room or a proportion thereof if some ventilation is provided from another source; and

(iii)

the ventilation opening to the adjoining room complies with Table 3.12.4.1 for the floor area of the adjoining room and the proportion of the habitable room that is ventilated from the adjoining room.

(c)

The requirements of (a) do not apply to buildings in Region D severe tropical cyclone areas (see Figure 3.10.1.4) provided the external walls are shaded with a verandah, balcony, eaves, carport or the like that projects at a minimum angle of 15 degrees in accordance with Figure 3.12.1.2.

Table 3.12.4.1 Minimum total ventilation opening area as a percentage of the floor area for each habitable room
Climate zone Without a ceiling fan or evaporative cooler With a ceiling fan With an evaporative cooler
1 10% 7.5% 10% (see Note)
2 10% 7.5% 10% (see Note)
3 10% 7.5% 7.5%
4 10% 5% 5%
5 7.5% 5% 7.5% (see Note)
6, 7 and 8 As required by Part 3.8.5 As required by Part 3.8.5 As required by Part 3.8.5

Note to Table 3.12.4.1: Because evaporative coolers are less effective than ceiling fans in more humid locations, the requirement for ventilation opening in climate zones 1, 2 and 5 with an evaporative cooler is the same as without one.

Explanatory information:

Explanatory information:

In humid locations, such as Darwin and Cairns, evaporative coolers would not provide the same cooling effect as in dryer climates. Although they would provide some benefit from the air movement if operated in a “fan-only” mode, they would cause discomfort, possible condensation and possible mould growth if operated in an evaporative “water-on” mode. However, even though a concession is not given in climate zones 1, 2 and 5, there are locations, particularly in climate zone 5, where evaporative coolers would be effective.

3.12.4.2 Ventilation openings

(a)

In climate zones 1, 2, 3, 4 and 5, the total ventilation opening area required by Table 3.12.4.1 to a habitable room must—

(i)

be connected by a breeze path complying with (b) to another ventilation opening in another room or space; or

(ii)

be provided by a minimum of two ventilation openings located within the same habitable room, with each ventilation opening having an area of not less than 25% of the area required by Table 3.12.4.1.

(b)

A breeze path required by (a)(i) must—

(i)

pass through not more than two openings in the internal walls with each opening having an area of not less than 1.5 m2; and

(ii)

have a distance along the breeze path between ventilation openings of not more than 20 m.

Explanatory information:

Explanatory information:
  1. Ventilation openings should be designed to allow the interior of the building to take full advantage of any natural breeze. Careful consideration should be given to the type and location of openings to ensure optimum effect is achieved and that internal “dead air pockets” are avoided.
  2. An opening may serve more than one breeze path.
  3. Two openings are stated in (b)(i) as the limit of the number of openings permitted in a breeze path. These are typically doorways. Larger openings, such as those between adjoining lounge and dining areas in the same space are unlikely to restrict air movement significantly.

3.12.4.3 Ceiling fans and evaporative coolers

Ceiling fans or evaporative coolers required to comply with 3.12.0.1, Tables 3.12.2.1a to 3.12.2.1h, as appropriate or Table 3.12.4.1 must—

(a)

be permanently installed; and

(b)

have a speed controller; and

(c)

for ceiling fans, serve the whole room, with the floor area that a single fan serves not exceeding—

(i)

15 m2 if it has a blade rotation diameter of greater than or equal to 900 mm; and

(ii)

25 m2 if it has a blade rotation diameter of greater than or equal to 1200 mm.