• Installation •
13 Connect breeching and venting systems
General venting information | Construct metal breeching: | ||||||||||||
• Model 80 boilers operate with positive overfire pressure. Adjust | • See Table 14 or Table 15 for minimum breeching diameter. | ||||||||||||
damper assembly (see page 33) during burner | • Select material type and thickness in compliance with local codes. | ||||||||||||
0.1" W.C. positive pressure at damper sample hole. | |||||||||||||
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| Conventional flue pipe should not be used as it could | |||||||||
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Select type of venting system |
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| leak flue gases and carbon monoxide emissions | ||||||||
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| through seams and joints, resulting in severe | |||||||||
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Forced draft |
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| personal injury or death. | ||||||
Boiler, breeching and stub vent operate at positive pressure. Entire | • Refer to ASHRAE Guide for chimney and breeching calculations | ||||||||||||
system must be | and construction and lining. | ||||||||||||
limited to prevent negative draft with |
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| Long horizontal breechings, excessive number of | ||||||||
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height above roof. See Figures 31 and 32. |
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| tees and elbows or other obstructions restricting | |||||||||
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Balanced draft |
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| combustion gas flow can result in possibility of | ||||||
Boiler operates with positive pressure overfire. Chimney may provide |
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| condensation,flue gas leakage and carbon monoxide | ||||||||
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| emissions, causing severe personal injury or death. | |||||||||
excess draft which may require a barometric draft control installed |
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and set to provide minimum draft to maintain 0.1" positive pressure |
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at flue collar. Minimum chimney height above roof is 3 feet. See |
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Figures 33 and 34. |
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| Table 14 Minimum breeching diameter — | |||||||||
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| forced draft venting | |||||
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Figure 31 |
| Figure 32 |
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Stub vent – forced draft — single boiler
Stub vent – forced draft — multiple boilers
Figure 33
Conventional chimney – balanced draft with barometric draft control when required — single boiler
Part No.
Figure 34
Conventional chimney – balanced draft with barometric draft control when required — multiple boilers
Table 15 Minimum breeching diameter — balanced draft venting
31 |