VENTING
4. VENTING
A.GENERAL
1.Install vent system in accordance with the "Venting of Equipment" Chapter of the National Fuel Gas Code, ANSI Z223.1/NFPA 54, the "Venting Systems and Air Supply for Appliances" Section of the CAN/CSA B149.1, Natural Gas and Propane Installation Code. or applicable provisions of the local building codes.
2.Do not connect vent connectors serving appliances vented by natural draft into any portion of mechanical draft systems operating under positive pressure.
3.Refer to the following venting options to determine which method is applicable.ON –
WARNING
All joints of positive pressure vent systems must be sealed completely to prevent leakage of flue products into the living space.
B.CHIMNEY VENTING
If venting into a masonry chimney; chimney must be lined with a fire clay tile liner or corrosion resistant metal liner. Type B vent may also be used as a lining system or as a stand alone chimney vent.
1.The vent system, when installed per the following instructions, will operate with a negative pressure (draft).
Table 4.1: Increaser & Chimney Size
Boiler | Increaser Size | Vent Size | Chimney | |
Model | Diameter | Height | ||
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|
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3" to 4" (7.6 to 10.2 cm) | 4" (10.2 cm) | 15' (4.5 m) | ||
3" to 5" (7.6 to 12.7 cm) | 5" (12.7 cm) | 15' (4.5 m) | ||
3" to 5" (7.6 to 12.7 cm) | 5" (12.7 cm) | 15' (4.5 m) | ||
3" to 5" (7.6 to 12.7 cm) | 5" (12.7 cm) | 15' (4.5 m) | ||
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|
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Figure 4.1: Chimney Venting
2.Horizontal portions of the venting system shall slope upward at least 1/4” per lineal foot (21 mm per meter) between boiler and chimney. The vent pipe shall be supported to prevent sagging; using metal strapping or equivalent means at no more than 4 ft. (1.2 meter) intervals.
3.Locate fan adapter, silicone, hardware and fan adapter gasket in boiler miscellaneous parts box and attach to blower outlet flange. Refer to Fig. 4.1 for details.
4.Apply 1/4” (6 mm) bead of silicone around fan adapter and slip increaser over the fan adapter. Refer to Table 4.1 for increaser and chimney sizes.
Increaser to be provided by installer.
5.Single wall vent pipe should be furnished between increaser and chimney. If the vent connector shall be located in or pass through a cold area, the vent connector shall be type B material.
C.DIRECT EXHAUST; HORIZONTAL VENTING
NOTICE
Flue gases will condense as they exit the vent termination. This condensate can freeze on exterior building surfaces which may cause discoloration of these surfaces.
1.This vent system will operate with a positive pressure in the vent pipe. Follow vent pipe manufacturers instructions for proper assembly of vent pipe and fittings.
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