FIGURE 1.2: HORIZONTAL CONCENTRIC VENTING (VENT OPTION 3,4)
6)Permitted Terminals for Vertical Venting -
•Vent Option 8 - Use Crown PN 230532 with the appropriate flashing (Table 1.6a)
•Vent Option 9 - Use Crown PN 230570 with the appropriate flashing (Table 1.6b)
7)Vertical Vent Terminal Locations (Vent Options 8,9) - Observe the following limitations on the location of all vertical vent terminals (see Figure 1.7):
•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 Options 8 & 9 has a fixed 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.
8)Wall thimbles – Concentric vent has a “zero” clearance to combustibles and therefore does not require the use of wall thimbles.
9)Pitch of Horizontal Piping - Pitch all horizontal piping 5/8” per foot so that any condensate which forms in the piping will run towards the boiler:
10)Supporting Pipe - 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 1.14) need only be supported at the terminal and at the base of the run.
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