035-17477-001 Rev. A (801)
16
Unitary Products Group
NOTE:
If installing furnace at altitudes between 2000 - 4500
ft., intake and vent pipe length must be reduced by 10 ft. If the
installation requires the maximum allowable intake and vent
pipe length, the furnace must be converted for high altitude
operation. Refer to the proper high altitude application
instruction for details.
VENT TERMINATION (2-PIPE)
Side wall horizontal vent terminals and roof mounted vertical
terminals may be field fabricated. Standard PVC/SRD fittings
may be used. Terminal configuration must comply as detailed
in this section.
NOTE:
Combustion air and vent pipes must terminate
together in the same atmospheric zone, either through a roof
or sidewall.
When selecting the location for combustion air/vent termina-
tion the following should be considered:
1.
Comply with all clearance requirements as listed below.
2.
Termination should be positioned where vent vapors will
not damage plants or shrubs or air conditioning equip-
ment.
3.
Termination should be located where it will not be
affected by wind gusts, light snow, airborne leaves or
allow recirculation of flue gases.
4.
Termination should be located where it will not be dam-
aged or exposed to flying stones, balls, etc.
5.
Termination should be positioned where vent vapors are
not objectionable.
VENT CLEARANCES (2-PIPE) U.S. ONLY
Dryer Vent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 ft.
Plumbing Vent Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 ft.
Gas Appliance Vent Terminal . . . . . . . . . . . . . . . . . . . 3 ft.*
From any mechanical fresh air intake . . . . . . . . . . . . . . 1 ft.
From any door, window or non-mechanical fresh air or
combustion air intake . . . . . . . . . . . . . . . . . . . . . . . . . . 1 ft.
Above grade and anticipated snow depth . . . . . . . . . . . 1 ft.
Above grade when adjacent to public walkway . . . . . . 7 ft.
From electric, gas meters, regulators and relief equipment -
min. horizontal distance . . . . . . . . . . . . . . . . . . . . . . . . 4 ft.
* Does not apply to multiple installations of this furnace
model. Refer to “VENTING MULTIPLE
UNITS" Section on page 17 .
NOTE:
Consideration must be given for degradation of build-
ing materials by flue gases.
NOTE:
Shaded components of the combustion air/vent sys-
tem shown in Figures 18 to Figure 23 are considered to be
part of the termination. These components should not be
counted when determining piping limitations. Sidewall termi-
nation may require sealing or shielding of building surfaces
with a corrosive resistance material to protect against com-
bustion product corrosion.
Table 5:
INTAKE/VENT PIPING 2-PIPE SYSTEM
Models P*DH/
FG9-DH/G9T-DH
Pipe Size
Max. Elbows vs. One Way
Vent Length (Ft.)
*
*.
Elbow count does not include (2) 90 ° elbows required
to pipe intake into burner box or those required for the
termination. See Step 4 under Combustion Air/Vent
Pipe Sizing
5-30
35
40
60
40 /37 / 1000 / A
2”
6
5
4
N/A
60 /55 / 1200 / B
80 /75 / 1200 / B
80 /75 / 1600 / C
100 /95 / 2000 / C
40 /37 / 800 / A
3”
8
7
6
5
60 /55 / 1200 / B
80 /75 / 1200 / B
80 /75 / 1600 / C
100 /95 / 2000 / C
120 /112 / 2000 / D
3" Only
6
5
4
N/A
NOTE:
Accessory concentric intake/vent terminations,
models 1CT0302 and 1CT0303 are available and
approved for use with these furnaces. Refer to Form
650.75-N2.4V for installation details
.
In Canada, refer to CAN/CGA-B149.1 or .2 Installation
Code (latest edition - Venting Systems and Air Supply)
FIGURE 18 :
Horizontal Termination Configuration with 12”
Minimum Clearance
OVERHANG
12” MINIMUM
VENT
MAINTAIN 12” CLEARANCE ABOVE
HIGHEST ANTICIPATED SNOW LEVEL
OR GRADE WHICHEVER IS GREATER
12 SEPARATION BETWEEN
BOTTOM OF COMBUSTION AIR
AND BOTTOM OF VENT
COMBUSTION AIR
90°
