In dwellings where the roof is lined with
sarking, ventilating directly into the roof space is no longer permitted
by building codes unless the space is adequately ventilated by open
eaves or roof vents. The Fantech Plus range offers many ducted solutions
for exhaust to outside through wall, roof or eaves to comply with
the latest building codes.
Paragraph 3.8.5.0 of the Building Code of Australia†
states:
Performance requirements P2.4.5
is satisfied for a mechanical ventilation system if it
is installed in accordance with AS1668.2 - Mechanical
ventilation for acceptable indoor air quality, except
that any contaminated air from a sanitary compartment
or bathroom must: -
(a)
Exhaust directly to outside
the building by way of ducts; or
(b)
Exhaust into the roof space
provided:
(i)
It is adequately ventilated
by open eaves, and /or roof vents; or
(ii)
The roof is clad in roofing
tiles without sarking or similar materials, which would
prevent venting through gaps between tiles.
Paragraph G4/AS 1 1.3.1 (c) (ii)* in New Zealand
states:
1.3.1 Mechanical ventilation
systems must satisfy the following conditions:
(c)
Extract ventilation shall:-
(ii)
Where provided to remove moisture
and other contaminants from kitchens, bathrooms, toilet
spaces and laundries in Housing, exhaust the air
to the outside at flow rates given in AS1668.2, Table
B1.
† Vol. 2 - Class 1 & 10 Building, Housing Provisions.
* This paragraph is part of the acceptable solutions G4/ASI contained
in the approved G4 ventilation and is used with the permission of
the Building Industry Authority.
