28
12 ”
MIN.
8” *
MIN.
20’
MAX
*18
″
Minimum for cold climates
(sustained temperatures 0
°
F and be-
low for 24 or more consecutive hours)
EXHAUST
INLET
8”
MIN.
GRADE LEVEL
SNOW LEVEL
OR
A07716
Fig. 20 -- Sidewall Termination with Exterior Risers to Get
Above Snow Level or Grade Level
Using Exterior Risers
1. Install elbows and pipe to form riser as shown in Fig. 20.
2. Secure vent pipe to wall with galvanized strap or other rust
resistant material to restrain pipe from moving.
3. Insulate pipe with Armaflex or equivalent moisture resist-
ant closed cell foam insulation or fiberglass insulation if
boxed in and sealed against moisture.
Vent Termination Shielding
Under certain wind conditions some building materials may be
affected by flue products expelled in close proximity to
unprotected surfaces. Sealing or shielding of the exposed surfaces
with a corrosion resistant material (such as aluminum sheeting)
may be required to prevent staining or deterioration. The
protective material should be attached and sealed (if necessary) to
the building before attaching the vent terminal.
A
A
B
A = 12
″
Above roof or snow accumulation level
B = 8
″
Min., 20
′
Maximum, except in areas with extreme cold temperatures (sustained
temperatures 0
°
F and below for 24 or more consecutive hours), then 18
″
Min.
A07717
Fig. 21 -- Rooftop Termination
Vertical Termination
1. Fig. 21 shows the proper installation and clearances for
vertical vent termination. The vertical roof termination
should be sealed with a plumbing roof boot or equivalent
flashing. The inlet of the intake pipe and end of the ex-
haust vent must be terminated no less than 12
″
(304.8 mm)
above the roof or snow accumulation level, and 12
″
(304.8
mm) away from a vertical wall or other protrusion.
2. If the vent system is installed in an existing chimney make
sure clearances shown in Fig. 21 are maintained. Horizont-
al section before the termination elbow can be extended on
the inlet air to provide necessary clearance.
Multi Vent Termination Clearances
When two (2) or more furnaces are vented near each other, each
furnace must be individually vented.
Two (2) vent terminations may be installed as shown in Fig. 22,
23, 24, 25, 26 and 27, but the next vent termination must be at
least 36
″
away from first 2 terminations. It is important that vent
terminations be made as shown to avoid recirculation of flue
gases.
Combustion
Air
Exhaust
12
″
Min. Grade
or Snow Level
36”
2”
36”
OR
A07718
Fig. 22 -- Concentric Vent and Combustion--Air
Roof Termination
“A”
Vent
Dimension “A” is touching or 2
″
maximum separation.
25--22--02d
Vent
Combustion Air
1
″
Maximum
(TYP.)
Exhaust
A07695
Fig. 23 -- Concentric Vent and Combustion Air
Sidewall Termination
PG9Y
AA
