Lochinvar 3.5, 2.5 service manual Multiple vent/air terminations

Installation & Operation Manual

3 Vertical direct venting

3.The vent piping must terminate in an up-turned coupling as shown in FIG. 3-1. The top of the coupling or the rain cap must be at least 36" (914 mm) above the air intake. The air inlet pipe and vent pipe can be located in any desired position on the roof, but must always be no further than 2 feet (.6 m) apart and with the vent termination at least 36" (914 mm) above the air intake.

4.Maintain the required dimensions of the finished termination piping as shown in FIG. 3-1.

5.Do not extend exposed vent pipe outside of building more than shown in this document. Condensate could freeze and block vent pipe.

Multiple vent/air terminations

1.When terminating multiple Crest boilers, terminate each vent/air connection as described in this manual (FIG. 3-3).

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

avoid recirculation of flue 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. 3-3). For Canadian installations, provide clearances required by CSA B149.1 Installation Code.

3.The air inlet of a Crest 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.

Figure 3-4Alternate Vertical Terminations with Multiple Boilers

36” (914 MM)

12”

(305 MM) 36” (914 MM)

12”

(305 MM)

Figure 3-3Vertical Terminations with Multiple Boilers

36” (914 MM)

12” 12”(305 MM)

12” (305 MM) (305 MM)

36” (914 MM)

12”

12”(305 MM) 12”(305 MM)

(305 MM)

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