035-17468-001 Rev. A (801)
16
Unitary Products Group
NOTE:
Shaded components of the combustion air/vent sys-
tem shown in the following figures are considered to be part
of the vent terminal. These components should not be
counted when determining piping limitations. Refer to Figure
18 thru Figure 20. Sidewall termination may require sealing or
shielding of building surfaces with a corrosive resistance
material to protect against combustion product corrosion.
VENTING MULTIPLE UNITS
Each unit must have its own intake/vent piping and termina-
tion. Do not use common pipes for combustion air or venting.
The vent terminals must be located as shown in refer to Fig-
ure 22 thru Figure 23.
FIGURE 18 :
Horizontal Termination Configuration with 12”
Minimum Clearance
FIGURE 19 :
Horizontal Termination Raised
Configuration for Additional Clearance
FIGURE 21 :
Vertical Termination
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°
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°
MAINTAIN 12” MINIMUM
CLEARANCEABOVE HIGHEST
ANTICIPATED SNOWLEVEL.
MAXIMUM OF 24” ABOVE ROOF.
VENT
COMBUSTION AIR
12” VERTICAL SEPARATION
BETWEEN COMBUSTION
AIR AND VENT
FIGURE 20 :
Horizontal Termination Configuration with
Horizontal Extension
FIGURE 22 :
Double Sidewall Termination
FIGURE 23 :
Double Rooftop Termination
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°
18” MAX.
VENT
COMBUSTION AIR
2”
6”
