User Guide

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9. Running PVC Vent Pipe Inside Enclosures and Through Walls - PVC vent pipe must be installed in a manner that permits
adequate air circulation around the outside of the pipe:
• Do not enclose PVC venting - Use CPVC in enclosed spaces, even if PVC is installed upstream.
• PVC venting may not be used to penetrate combustible or non-combustible walls unless all of the following conditions
are met:
a. The wall penetration is at least 66 inches from the boiler as measured along the vent.
b. The wall is 12” thick or less.
c. An airspace of at least that shown in Figure 7.4 is maintained around the OD of the vent.
If any of these conditions cannot be met, use CPVC for the wall penetration.
10. VentManufacturer’sInstructions–Whereapplicable,ventsystemmanufacturersmayhaveadditionalventsystemdesign
requirements.Readandfollowtheventmanufacturer’sinstructionsinadditiontothoseshownhere.Whereaconictarises
between the two sets of instructions, the more restrictive requirements shall govern.
FIGURE 7.3: EXPANSION LOOPS FOR CPVC/PVC PIPE
FIGURE 7.3bFIGURE 7.3a
FIGURE 7.3c