Prepare Roof Penetrations; Multiple Vent/Air Terminations - Lochinvar FTxl 400 Installation & Operation Manual

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:
• 5½ inch hole (140 mm) hole? for 4 inch (102 mm)
vent pipe
• 7½ inch hole (191 mm) hole? for 6 inch (152 mm)
vent pipe
b. Insert a galvanized metal thimble in the vent pipe
hole (when required by local codes).
3. Space the air and vent holes to provide the minimum
spacing shown in FIG.'s 5-1A and 5-1B, page 31.
4. Follow all local codes for isolation of vent pipe when
passing through fl oors, ceilings, and roofs.
5. Provide fl ashing and sealing boots sized for the vent pipe
and air pipe.

Multiple vent/air terminations

1. When terminating multiple FTXL boilers, terminate each
vent/air connection as described in this manual (FIG.
5-2).
Terminate all vent pipes at the same height
WARNING
and all air pipes at the same height to
avoid recirculation of fl ue products and
the possibility of severe personal injury,
death, or substantial property damage.
2. Place roof penetrations to obtain minimum clearance
of 12 inches (305 mm) 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 FTXL boiler is part of a direct vent
connection. It is not classifi ed as a forced air intake with
regard to spacing from adjacent boiler vents.
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Installation & Operation Manual
Figure 5-2 Vertical Terminations with Multiple Boilers
Figure 5-3 Alternate Vertical Terminations with Multiple
Boilers