NTI INSTALLATION MANUALS

Part 5 - Venting

2. Venting Through an Existing System

Concentric Venting Through an Existing System NOTE: The following instructions refer only to venting through an existing vent system, and not to venting with NTI’s optional concentric vent kits. Refer to Concentric Vent Kit installation manual (LP-166) for further information on venting with the optional concentric vent kits. Concentric venting through an existing system must run vertically through the roof. See Table 18 for proper minimum vent sizing. Use only the approved venting materials speci ed in Table 12 for piping the system. All instructions listed in this Venting section apply. See Figures 54-1 and 54-2 for venting demonstrations. Chase Venting Through an Existing System When venting as a chase, follow all instructions included in this Venting section, including those in the previous Concentric Venting Through an Existing System section. See Figure 54-3 for chase venting demonstration.

This boiler may be vented through an existing unused vent system. The inner diameter of the existing vent system is utilized for the combustion air source. Two methods have been approved for such venting: Concentric Venting Through an Existing System and Venting as a Chase. Vent / Air Inlet Size Minimum Existing Vent / Chase Size 2” 4” 3” 5”

Table 18 - Minimum Existing Vent / Chase Sizing

DANGER

Do not install the boiler into a common existing vent with any other appliance. This will cause ue gas spillage or boiler malfunction, resulting in substantial property damage, serious personal injury, or death. The upper and lower vent terminations as well as all joints in the venting system must be properly sealed to ensure that all combustion air is drawn properly and exhaust does not leak from the system. Failure to properly seal the venting system will result in property damage, serious personal injury, or death. Contractors must check state and local codes before installing through an existing vent opening. State and local codes always take precedence over manufacturer’s instructions. Failure to check state and local codes before installing through an existing opening could result in property damage and add signi cantly to installation costs. If an existing venting system is converted for use with this boiler, the installer must ensure that the existing venting system is clean and free from particulate contamination that could damage the boiler. Failure to do so could result in property damage and boiler failure. Such failure IS NOT covered under warranty. CAUTION

EXHAUST Concentric Venting through an Existing System 1

EXHAUST Concentric Venting through an Existing System 2

Chase Venting Through an Existing System 3

EXHAUST

SEAL

SEAL

24"

AIR INLET

COMBUSTION AIR

COMBUSTION AIR

SEAL

EXISTING

EXISTING VENT

EXISTING

w/SCREEN AIR INTAKE

Intake

SEAL

12" MIN.

Exhaust Exhaust

(w/SCREEN) AIR INTAKE

SEALED CAP

SEAL

SEAL

Intake

SEALED

LP-700-B 03/27/19

Intake

CAP

Exhaust

LP-325-MM 03/15/12

CAP

SEAL

LP-325-LL

Figure 54 - 1, 2 - Concentric Venting Through an Existing System, 3, Chase Venting Through an Existing System

NOTE: These drawings are meant to demonstrate system venting only. The installer is responsible for all equipment and detailing required by local codes.

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