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Permitted Terminals for Vertical Venting6) - Use Crown PN 230532 with the appropriate ashing (Table 7.3b)
Vertical Vent Terminal Locations (Vent Option 5)7) - Observe the following limitations on the location of all
vertical vent terminals (see Figure 7.7):
The top of the vent pipe must be at least 2 feet above any object located within 10 feet.•
The bottom of the air inlet terminal must be at least 12” above the normal snow accumulation that can be •
expected on the roof. The terminal used in Vent Option #5 has a xed distance above the storm collar of
19”. If a greater distance is needed to provide the clearance above the snow line, build a chase on the
roof and mount the vertical terminal on top of the chase.
Wall thimbles8) – Concentric vent has a “zero” clearance to combustibles and therefore does not require the
use of wall thimbles.
Pitch of Horizontal Piping9) - Pitch all horizontal piping so that any condensate which forms in the piping will run
towards the boiler. Pitch Crown horizontal concentric venting 5/8” per foot
Supporting Pipe10) - Vertical and horizontal sections of pipe must be properly supported. Support Crown
concentric venting near the female end of each straight section of pipe. Exception: Vertical runs of concentric
pipe in an unused chimney (Figure 7.36) need only be supported at the terminal and at the base of the run.
table 7.5: Vent/ air Intake Fitting Equivalent lengthVENT FITTING EQUIVALENT LENGTH (ft)
60/100mm 90° CONCENTRIC ELBOW 4.5
60/100mm 45° CONCENTRIC ELBOW 4.0
80/125mm 90° CONCENTRIC ELBOW 8.5
80/125mm 90° SWEEP CONCENTRIC ELBOW 5.5
80/125mm 45° CONCENTRIC ELBOW 3.0
80/125mm 90° CONCENTRIC SUPPORT ELBOW 8.5
table 7.6: Summary of Vertical Venting options VENT OPTION # 56
CLASSIFICATION USED IN THIS
MANUAL
VERTICAL
CONCENTRIC
RESERVED FOR
FUTURE USE
ILLUSTRATED IN FIGURE 7.7
VENT PIPE PENETRATION
THROUGH STRUCTURE ROOF
VENT PIPE SIZE 80/125mm
CONCENTRIC
INLET AIR ORIFICE SIZE 82mm
MAX. VENT LENGTH 27ft - 10in
MIN. VENT LENGTH 6in
VENT TERMINAL
CROWN #230532
CONCENTRIC
TERMINAL (TABLE
7.3b)
VENT MATERIAL
CROWN 80/125 mm
VENT COMPONENTS
SHOWN IN TABLE
7.3b