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4. REDUCING CLEARANCES TO
COMBUSTIBLES
If it is necessary to install a heater closer to a
combustible surface than the stated requirements
in Section 3 of this Installation Guide, 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
shieldmustbexedtothesurfacethatrequires
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)toallowacontinuousairow.Itisthisair
owthatkeepsthesurfacerequiringprotection
cool.Fixingsshouldnotimpedethisairow.
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
ueisnowclosertothewalltheshieldingshould
alsoprotectthewallfromtheuepipe.
For example:
Side wall clearance for the B600 is 425 mm.
A 12mm gapped shield on the wall with a factor
of 0.40.
Calculate:-425mmx0.40=170mm.Thisisthe
new side wall minimum clearance.
The shielding needs to be large enough so that
none of the original clearances of 425 mm are
compromised.
5. INSTALLING THE FLUE
Theuesystemusedwheninstallingtheheater
MUST comply with the current installation standard
AS/NZS 2918.
Fullinstructionsontheinstallationoftheuewillbe
suppliedwiththeuekit.TheseMUSTbefollowed
closely, including the minimum exit height from
thetopoftheoorprotectorbeingnotlessthan
4.6m, and the minimum exit height above the roof
line of roof ridge as detailed in the instructions.
Theuemustbettedwithoneofthefollowing:
1. Rear Flue Shield:
a. 900 mm long, minimum 160° arc,
stainlesssteelpaintedblackrearue
shield with 25mm gap between it and
the150mmdiameteractiveue,and
25mm above the top of the heater.
2. Decro-mesh/SolidFlueShield:
Note: MUST be installed with the manufacturer’s
490mmtallinnerueshieldANDventilateddecro-
mesh locating ring.
a. A full length, half radius perforated
decro-meshueshieldextending
from the heater through into the drop
box penetrating the ceiling with the
perforated surface facing the front,
ORequivalentinsolidouterueshield
casing (7.75” diameter)
b. The 490 mm half round stainless steel
innerreectorsuppliedwithheater
mustbettedinsidethedecro-mesh
orsolidouterueshield.
c. Themanufacturer’sdecro-mesh
‘locating ring’ must be used to
supporttheueshieldingandinner
shield up off the heater top. It is
important that air can be drawn
intothebaseandrearoftheue
shielding.