4
2.7.
REDUCING CLEARANCES TO COMBUSTIBLES
If it is necessary to install a heater closer to a combustible
surface than the stated requirements in this installation
manual, it must be done in accordance with Australian
Standard AS/NZS 2918:2018 Section 3, Tables 3.1 & 3.2.
Shield Construction: The shield shall be constructed from a
heat resistant material. The shield must be fixed to the surface
that requires protection and NOT the heater.
The Standard allows three options to reduce stated
clearances.
Single layer of continuous material with Minimum Air Gap of
12mm — Clearance Factor = 0.40
Single layer of continuous material with Minimum Air Gap of
25mm — Clearance Factor = 0.30
Two spaced layers of continuous material with Minimum Air
Gaps of 12mm + 12mm — Clearance Factor = 0.20
The shielding must be open at the top and bottom (vented) to
allow a continuous air flow. It is this air flow that keeps the
surface requiring protection cool. Fixings should not impede
this air flow.
The shielding needs to go far enough along and up the wall so
that the original side and rear required clearances are not
compromised. As the flue is now closer to the wall the
shielding should also protect the wall from the flue pipe.
Example:
The side wall clearance for a heater is 750mm.
A 12mm gapped shield on the wall with a factor of 0.40.
Calculate: 750mm x 0.40 = 300mm. This is the new side wall
minimum clearance.
The shielding needs to be large enough so that none of the
original clearances of 750mm are compromised.
2.8.
INSTALLING THE FLUE
The flue system used when installing the open fireplace MUST
comply with the current installation standard AS/NZS 2918.
Full instructions on the installation of the flue will be supplied
with the flue kit. These MUST be adhered to, including the
minimum exit height from the top of the floor protector being
not less than 4.6m, and the minimum exit height above the
roof line of roof ridge as detailed in the AS/NZS 2918.
The flue kit is supplied with the freestanding open fireplace.
Note that this flue kit is different to the one supplied with the
Built-in model of N900. They are not interchangeable.
The freestanding flue kit consists of:
4 x 900mm lengths of 8 inch stainless steel active flue
1 x 900mm length of 10 inch, slotted stainless steel
outer casing with an external rear heat shield fitted,
painted black
1 x 900mm length of 10 inch stainless steel outer
casing with an internal rear heat shield painted black
2 x 900mm lengths of 10 inch stainless steel outer
casing
2 x 900mm lengths of 12 inch galvanised steel outer
casing
1 x 12 inch ceiling drop box with 5000mm
2
ventilation
1 x ceiling flange
1 x stainless steel flue cowl for 8 inch flue
1 x angle support brackets
1)
Installing 8 inch active flue – the first length of 8 inch
stainless steel flue inserted into the spigot of the
appliance can be differentiated by the other three lengths
by a larger crimp and swage at one end. Install the
remaining three lengths of 8 inch flue as normal.
2)
10 inch outer casing with external shield – the first
length of outer casing, resting on top of the appliance, is
the slotted length with the external heat shield. Orientate
the outer casing so that the external shield is closest to
the rear wall.
3)
10 inch outer casing with internal shield – the second
length of outer casing, inserted into the first length, is the
one with the internal heat shield. Orientate the second
length of outer casing so that the internal shield is closest
to the rear wall.
4)
Additional black-painted 10 inch outer casing –
depending on the height of the ceiling above the
appliance, it may be necessary to order an additional
length of 10 inch stainless steel outer casing painted black
so that it may extend into the ceiling drop box.
All other aspects of the flue kit must be installed in
accordance with AS/NZS 2918.
