Navien NHB Series, Installation & Operation Manual

Page: 81 / 135

81 Installing a Common Vent System
9.4 Connecting and Terminating the Vent Pipe
Refer to the following example to install the common vent system. The installation area should be measured to ensure that sufficient space is
available to install the boiler units and the common vent system. Ensure that the common vent system is installed near the boiler units while
satisfying all clearance requirements that are specified in this manual as well as the Installation Manuals supplied with the boiler units.
9.4.1 Connecting the Main Pipe Runs to Wye Joint or Wye Assembly
After connecting the wye joint or wye assembly, connect the main trunk pipe to each side of the wye joint or wye assembly. Each trunk pipe is
connected to the other wye joint or wye assembly. Refer to “Connecting Pipes with Cement” on page 75 for more information.
Note
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The pipe branch that connects the individual appliance to the common vent trunk must be within 20 equivalent feet.
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It is recommended to install the exhaust vent pipe end connected to the trunk pipe at a 45˚ angle in relation to the exhaust
direction. (The exhaust resistance increases if connected to the trunk pipe at a 90˚ angle.)
9.4.2 Installing the System Termination
End caps, pipe elbows or tee joints can be used at the open ends of the intake and exhaust vent pipes. Refer to the following installation
examples that depict how the parts are fitted at the end of the common vent system piping.
End Cap
Field Supplied Termination
Screen (Optional)
Note
The illustration is intended for reference purposes only.