Lochinvar 51-211 Prepare roof penetrations, 2Vertical Terminations with Multiple Boilers

5 Vertical direct venting

Vent/air termination – vertical

Prepare roof penetrations

1.Air pipe penetration:

a.Cut a hole for the air pipe. Size the air pipe hole as close as desired to the air pipe outside diameter.

2.Vent pipe penetration:

a.Cut a hole for the vent pipe. For either combustible or noncombustible construction, size the vent pipe hole with at least a 1/2 inch clearance around the vent pipe outer diameter:

•3½ inch hole for 2 inch vent pipe

•4½ inch hole for 3 inch vent pipe

b.Insert a galvanized metal thimble in the vent pipe hole.

3.Space the air and vent holes to provide the minimum spacing shown in FIG. 5-1A, page 29.

4.Follow all local codes for isolation of vent pipe when passing through floors, ceilings, and roofs.

5.Provide flashing and sealing boots sized for the vent pipe and air pipe.

Multiple vent/air terminations

1.When terminating multiple Knight wall mount boilers, terminate each vent/air connection as described in this manual (FIG. 5-2).

￿WARNING Terminate all vent pipes at the same height and all air pipes at the same height to

avoid possibility of severe personal injury, death, or substantial property damage.

2.Place roof penetrations to obtain minimum clearance of 12 inches between edge of air intake elbow and adjacent vent pipe of another boiler for U.S. installations (see FIG. 5-2). For Canadian installations, provide clearances required by CSA B149.1 Installation Code.

3.The air inlet of a Knight wall mount boiler is part of a direct vent connection. It is not classified as a forced air intake with regard to spacing from adjacent boiler vents.

Installation & Operation Manual

Figure 5-2Vertical Terminations with Multiple Boilers

Figure 5-3Alternate Vertical Terminations with Multiple Boilers

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