W415-1066 / A / 03.06.12
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The hmf100 may be installed without a return air plenum and duct system only when the hmf100 is
configured with the napoleon diffusion Plenum (hmfk-dP).
ONLY UsE kITs OR ACCEssORIEs TEsTED AND AppROvED FOR UsE wITH THE HMF100. UsINg
NON AppROvED kITs vOIDs wARRANTY AND INCREAsEs RIsk OF pROpERTY DAMAgE AND
pERsONAL INjURY.
72”
(1829 mm)
1”
(25 mm)
4”
(102 mm)
40”
(1016 mm)
A
B
C
NOTE:
See CAN/CSA-B365.01
and NFPA211 for
clearance to
combustible
specifications for
return air ducting.
CLEARANCE TO COMBUSTIBLES
*Drawing not to scale.
72”
(1829 mm)
MINIMUM CEILING HEIGHT
(measured from base of HMF100):
• connected to HMFK-DP Diffusion
Plenum 7ft. 6” (2286 mm)
• connected to standard plenum/
duct systems 6ft. 6” (1981 mm)
NOTE
- The Napoleon Diffusion Plenum
(HMFK-DP) is the only diffusion plenum
certified for use with the HMF100 furnace.
SEE MANUAL
DRAWING DEPICTS
STANDARD PLENUM/
DUCT SYSTEM
Plenum & ducTing cleArAnce To
combuSTibleS
SecTion
A
b
c
ToP
4” (102 mm)
4” (102 mm)
1” (25 mm)
boTTom/SideS
4” (102 mm)
6” (152 mm)
1” (25 mm)
When installing an hmf100 without a return air plenum the filter rack and filter must be installed on the rear
panel of the furnace behind the blower. failure to comply with this requirement may result in smoke and ash
being drawn in through the intake and distributed out through the blower.
• The first 72” (1829 mm) run of horizontal ducting coming off the supply ple-
num must maintain a cross sectional area of 110 square inches (710 cm
2
)
(total sum of main duct and branch ducts cross sections). use the following
chart when connecting round ducting directly to supply plenum:
MIN. # OF DUCTs
REqUIRED
DUCT
DIAMETER
9
4” (102 mm)
6
5” (127 mm)
4
6” (152 mm)
The initial run of horizontal duct branching off the supply plenum shall maintain a cross
sectional area of minimum 110 square inches (710 cm
2
).
cAuTion
!
!
• All plenum and ducting clearances must satisfy specification set forth in cAn/cSA-b365.01 and nfPA211.
5.3.3 INSTALLATION wITH THE HmFk-dP dIFFuSION PLENum
