Advertisement
TaNe 9--Maximum
Allowable
Exposed Vent Pipe Length {ft) With and Without
Insulation
in Winter
Design
Temperature
Ambient*
WINTER
DESIGN
MAX PBPE
FURNACE
WITHOUT
W_TH 3t8=lN. OR
TEMPERATURE
DIAMETER
SRZE
(°F)
(BN.}
INSULATION
THICKER
INSULATIONt
20
1.5
51
70
0
1.5
28
70
-20
1.5
16
70
040
20
2
45
70
0
2
22
70
-20
2
10
58
20
2
65
70
060
0
2
35
70
-20
2
20
70
20
2
55
55
0
2
48
55
-20
2
30
55
080
20
2.5
70
70
0
2.5
47
70
-20
2.5
28
70
20
2.5
40
40
0
2.5
40
40
-20
2.5
38
40
100
20
3
70
70
0
3
50
70
-20
3
28
70
20
3
70
70
0
3
61
70
-20
3
37
70
120
20
4
70
70
0
4
48
70
-20
4
23
70
* Pipe length (fi) specified
for maximum
pipe lengths located Jn unconditioned
spaces. Pipes located in unconditioned
space cannot exceed total allowable
pipe length
as specified
in Table 9.
? Insulation
thickness
based on R value of 35 per in.
FIELD
LOCATION
=FACTORY
INSTALLED
LOCATION
I
A00212
Fig. 31--Relocating
&Box
c Install
pipe
support
(_ilctow-supplied
in loose
parts
bag)
into selected
fimaace casing combustion-air
pipe hole. Pipe
support
should
be positioned
at bottom
of casing
hole.
d. Insert
assembled
combustion-air
inlet
pipe
into
intake
housing.
29
e. Make sure elbow is oriented
in an acceptable
direction
and
that the minimum
clearance
of 3 in is observed.
(See Fig.
34.)
L Drill a 1/8-in. hole in 2=in. combustion=air
inlet pipe using
hole in intake
housing
as a guide
g. Install
a field-supplied
No. 6 or No. 8 sheet metal
screw
into combustion-air
pipe
h
Install
casing
hole
filler
cap (factow-supplied)
in loose
parts bag)
in unused
combustion-air
pipe casing
hole
NOTE:
Do not attach combustion-air
intake pipe permanently
to
combustion-air
intake honsing
since it may be necessaw
to remove
pipe for service
of igniter
or flame sensor.
(OMBUSTION=AIR
INTAKE
HOUSING
PLUG
FITTING
The combustion-air
intake
plug
fitting
must
be installed
in
unused
combustion-air
intake
housing
This
fitting
must
be
attached
by using
RTV sealant,
or by &illing
a 1i%im hole in
fitting,
using
hole
in intake
housing
as a guide.
Install
a
field-supplied
No. 6 or No. 8 sheet metal
screw.
NOTE:
DO NOT
OVERTIGHT]EN
SCREW.
Breakage
of intake
housing
or fitting
may cause air leakage
to occur.
Advertisement
