7.If improper venting is observed during any of above tests, the venting system must be corrected.
Vent system or vent connectors may need to be resized. For any other appliances when resizing vent systems or vent connectors, system or connector must be sized to approach minimum size determined in appropriate table in NFGC or NSCNGPIC.
II.COMBUSTION-AIR AND VENT PIPING
A.General
WARNING: Solvent cements are combustible. Keep away from heat, sparks, and open flame. Use only in
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In Canada construct all
B. Combustion Air Pipe
CAUTION: Combustion air must not be taken from inside a structure that is frequently contaminated by halogens, which include fluorides, chlorides, bromides, and iodides. These elements are found in aerosols, detergents, bleaches, cleaning solvents, salts, air freshen- ers, adhesives, paint, and other household products. Locate
Excessive exposure to contaminated combustion air will result in safety and performance related problems.
NOTE: Furnace
Furnace
NOTE: All pipe joints must be watertight except attachment of
Install combustion air inlet pipe as follows:
1.Assemble
a.Permanently install perforated disk assembly (factory- supplied in loose parts bag) in
For 120,000 Btuh size units only: Separate the 2 halves of perforated disk assembly and use only the shouldered disk half.
Ð23Ð
b.Determine length of straight portion of
c.Cut
d.Permanently attach elbow/perforated disk assembly to straight portion of pipe using RTV or by cementing. (See Fig. 29.)
2.Attach
NOTE: Select 1 vent pipe connection and | NOTE: Select 1 vent pipe connection and | |||||||||||||||||||||||||||||||||||||||||||||||||||
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COMBUSTION- |
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| COMBUSTION- | COMBUSTION- | |
| AIR | AIR | AIR |
| FLOW |
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UPFLOW | DOWNFLOW |
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COMBUSTION- | COMBUSTION- |
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AIR | AIR | VENT |
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FLOW |
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A96188
CAUTION: Make sure there is adequate clearance
Fig. 28ÐCombustion-Air and Vent Pipe Connections
a. Determine location of
b.Reposition
c.Install pipe support
d.Insert assembled
e.Make sure elbow is oriented in an acceptable direction and that the minimum clearance of 3 in. is observed. (See Fig. 28.)
f.Drill a
g.Install a