VENT SYSTEM
This furnace is certified to be installed with one of two possible vent configurations.
1.Horizontal vent system. This vent system can be installed com- pletely horizontal or combinations of horizontal, vertical, or offset using elbows.
2.Vertical vent system. This vent system can be installed completely vertical or a combination of horizontal, vertical, or offset using elbows.
VENT APPLICATIONS AND TERMINATION
When selecting the location for a combustion air / vent termination, the following should be considered:
1.Observe all clearances listed in vent clearances in these instruc- tions.
2.Termination should be positioned where vent vapors will not dam- age plants or shrubs or air conditioning equipment.
3.Termination should be located where it will not be affected by wind gusts, light snow, airborne leaves or allow recirculation of flue gases.
4.Termination should be located where it will not be damaged or exposed to flying stones, balls, etc.
5.Termination should be positioned where vent vapors are not objec- tionable.
6.Horizontal portions of the vent system must slope upwards and be supported to prevent sagging.
7.Direct vent systems must be installed so the vent and the combus- tion air pipes terminate in the same atmospheric zone. Refer to Figures 13 or 14.
Maintain 12” minimum clearance above highest anticipated snow level. Maximum 24” above roof.
12” Min.
12” Min.
FIGURE 29: Termination Configuration - 1 Pipe
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| 12” vertical separation |
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Maintain 12” minimum | between combustion air | 12” minimum | |||
intake and vent. | |||||
clearance above | below overhang | ||||
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highest anticipated |
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| 12” minimum | ||
snow level. |
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| bottom of | |
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| combustion air pipe | |
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| and bottom of vent. | |
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| minimum clearance | |
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| above highest | |
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| level or grade, | |
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| whichever is higher. |
FIGURE 30: Termination Configuration - 2 Pipe
12” MIN.
12” Minimum below overhang
12” MIN.
12” Minimum separation between bottom of combustion air intake and bottom of vent
Maintain 12” minimumclearance above highest anticipated snow level or grade, whichever is higher
FIGURE 31: Termination Configuration - 2 Pipe Basement
VENTING MULTIPLE UNITS
Multiple units can be installed in a space or structure as either a single pipe configuration or a
The combustion air side of the single pipe configuration shown in Figure 29 is referred to in these instructions as ambient combustion air supply. Follow the instructions for ambient combustion air installations, paying particular attention to the section on air source from inside the building. The vent for a single pipe system must be installed as specified in the venting section of these instructions with the vent terminating as shown in Figure 29. Each furnace must have a separate vent pipe. Under NO circumstances can the two vent pipes be tied together.
The combustion air side of the
VENT
COMBUSTION AIR
2”
MIN.
FIGURE 32: Double Horizontal Combustion Air Intake and Vent Termination
MIN.
6”
FIGURE 33: Double Vertical Combustion Air Intake and Vent Termination
24 | Johnson Controls Unitary Products |