
7
g. Wiring materials located in the return duct system shall
conform to Articles 300-22 of the National Electrical
Code (ANSI C1/NFPA-70).
h. Gaspipingisnotruninorthroughthereturnductsystem.
i. Test the negative pressure in the closet with the air-
circulating fan operating at high speed and the closet
closed.Thenegativepressureistobenomorenegative
than minus 0.05 inch water column.
j. Forfloorreturnsystems,themanufacturedhomemanu-
facturer shall affix a prominent marking on or near the
appliance where it can be easily read when the closet
door is open. The marking shall read:
k. Airconditioningsystemsmayrequiremoreduct,register
and open louver area to obtain necessary airflow. Use
NORDYNE’s certiduct program to determine proper
duct size for A/C.
Air Distribution Systems
For proper air distribution, the supply duct system must be
designedsothatthestaticpressuremeasuredexternaltothe
furnace does not exceed the listed static pressure rating
shown on the furnace rating plate.
Before installing an air conditioner system, consult home
manufacturerforductsystemmaximumcapacity. Location,
size,andnumberofregistersshouldbeselectedonthebasis
of best air distribution and floor plan of the home.
Table 3. Roof Jack Assemblies
CAUTION:
HAZARDOFASPHYXIATION:Donotcoveror
restrict return air opening.
!
3. VENTING AND COMBUSTION AIR
ROOF JACK SELECTION
Note: Install only Roof Jack Assemblies listed in Table 3 on
this heating appliance.
a. Determine depth of ceiling cavity from center of roof
openingtocenterofceilingopening.(SeeDimension“A”
in Figure 1).
b. Determine ceiling height and subtract height of furnace.
(See Dimension “B” in Figure 1).
c. Add dimensions A + B (and X from Table 3 and Figure 2
ifslantdeck flashingisused). The totallengthof (A+B +
X) must be within the minimum and maximum range of
one of the Roof Jacks listed in Table 3.
ROOF JACK TROUBLE SHOOTING
The roof jack assembly is a telescoping type assembly (see
selection)thatismadeupofapipewithinapipeconstruction.
Theinner pipe(5”)is fortheflue gasesto exit thehome. The
outerpipe(8”)isusingthespacein-betweenthe5”and8”pipe
forcombustionair. Ifthefurnaceissmotheringitselfout,after
ashorttime,onnaturaldraftmodels,orpressureswitchdoes
notmakecontactonM1Mmodel,slideupairinletafewinches
and check for debris in pipe. Clean out and check complete
flue assembly for blockage. On new homes make sure no
building materials fell in the top (air inlet or exhaust). Also
removetopandmakesurenoseamshaveopeneduponroof-
jackassembly. OntheM1Gfurnace(naturaldraftmodel)the
airinletlimittrippingiscausedfromaunbalanceddraft,which
means the air inlet becomes a better flue than the flue itself.
Check-out Procedure:
Is furnace filter clean?
Iffurnaceisinstalledincloset,whatisthelouveropenarea?
The installation instructions state the minimum open area
required is 235 sq. in., or 390 sq. in. for 5 ton.
Inspect roof-jack for internal blockage.
Inspect inside of upper combustion air box for debris.
With burner removed, reach inside lower air box into com-
bustion air chute to check for debris (insulation, roofing
material, drywall, etc.) and look in the bottom of the heat
exchanger for debris.
SSAW T27 47 - 2
AW= ALL WEATHER
FLASHING
PITCH/12" RISE
0=FLAT
2=2.5/12
4=4/12
MIN. ADJ.
LENGTH
F=
S= FLAT FLASHING
SLANT FLASHING TYPE:
BLANK=NON-TRANSIT
T= TRANSIT MODE MAX. ADJ.
LENGTH
FLUE STEEL TYPE
A= ALUMINIZED
S=STAINLESS
Approx. Length
Model Number Below Flashing
(F,S)AW(T)1523-(0,2,4)(A,S) 15" - 23"
(F,S)AW(T)2135-(0,2,4)(A,S) 21" - 35"
(F,S)AW(T)2747-(0,2,4)(A,S) 27" - 47"
(F,S)AW(T)3563-(0,2,4)(A,S) 35" - 63"
(F,S)AW(T)5195-(0,2,4)(A,S) 51" - 95"