Heatilator A36C - Hearth Extension, Building and Finishing

Heatilator • A36/42C, A36/42CH • Installers Manual • 4017-262 • Rev D • 10/07/13
28
B. Hearth Extension, Building and Fin-
ishing
Table 7.1
R = 1/k x inches of thickness
Table 7.2
WARNING! Risk of Fire! High temperatures, sparks,
embersorotherburningmaterialfallingfromthere-
place may ignite ooring or concealed combustible
surfaces.
• ProtectivemetalhearthstripsMUSTbeinstalled.
• Hearth extensions MUST be installed exactly as
specied.
Ahearthextensionmustbeinstalledwithallre-
placestoprotectthecombustibleoorinfrontofthe
replacefrombothradiantheatandsparks.
• You MUST use a hearth extension with this
replace.
• RefertoFigure7.3forminimumdimensions.
• Thisreplacehasbeentestedandapprovedforuse
withahearthextensioninsulatedtoaminimumR
valueof1.03.
• ThehearthextensionmaterialMUSTbecovered
withtile,stoneorothernon-combustiblematerial.
• Manufacturedhearthmaterialswillusuallyhavea
publishedR value(resistancetoheat)ork value
(conductivityofheat).RefertotheformulainTable
7.1toconvertakvaluetoanRvalue,
• RefertoTable7.2forhearthextensioninsulation
alternatives.
WARNING! Risk of Fire!
Hearth extensions are to be installed only as illustrated to prevent
high temperatures from occurring on concealed combustible
materials.
WARNING! Risk of Fire!
• Maintainclearances.
• Useonlynon-combustiblematerialbelowstandoffs,material
such as cement board is acceptable.
• Framingornishingmaterialusedonthefrontofthereplace
closer than the minimums listed, must be constructed entirely
of non-combustible materials (i.e., steel studs, concrete board,
etc.).
WARNING! Risk of Fire!
Hearth & Home Technologies is not responsible for
discoloration, cracking or other material failures of
nishingmaterialsduetoheatexposureorsmoke.
 • Choosenishingmaterialscarefully.
Figure 7.3 Hearth Extension Dimensions
C
B
A
C
Hearth Extension Dimensions
Model # A B C
A36
(HX3)
in. 52 16 8
mm 1321 406 203
A42
(HX4)
in. 66 20 12
mm 1676 508 305
Hearth Extension Insulation Alternatives, R Value = 1.03
Material
k per inch
thick
r per inch
thick
Minimum
thickness
required
Hearth&HomeHX3,HX4 0.49 2.06 1/2in.
USGMicore300™ 0.49 2.06 1/2in.
USGDurock™CementBoard 1.92 0.52 2in.
CementMortar 5.0 0.20 51/8in.
CommonBrick 5.0 0.20 51/8in.
CeramicTile 12.50 0.08 121/4in.
Armstrong™PrivacyGuardPlus 0.46 2.18 1/2in.
Marble 14.3-20.0 0.07-0.05 14 5/8 in. - 20 3/8 in.