Design Requirements Unique To Horizontal Twin Pipe Venting Systems - Burnham K2WTC Installation, Operating And Service Instructions

VII. Venting
B. Design Requirements Unique to Horizontal Twin Pipe Venting Systems
Table 7.5 summarizes all horizontal twin pipe vent options. Illustrations of horizontal twin pipe vent systems are shown in
Figures 7.6 – 7.10. In addition to the requirements in Section VII - A, observe the following design requirements:
1. Permitted Terminals for Horizontal Venting:
Terminal Option A: Fittings (Acceptable for Vent Options 1-4) – Vent terminates in a plain end (coupling for PVC, bell
end for PolyPro, Polyflue and plain end pipe for InnoFlue). Intake terminates in a PVC 90 sweep elbow pointing down.
Outer edge of both terminals must be within 10" of the wall surface (Figures 7.6, 7.9). The section of DuraVent PolyPro,
Centrotherm InnoFlue or Selkirk Polyflue exposed to the outdoors must be UV resistant.
Use of rodent screens (not supplied) is generally recommended for both terminations. These can be fabricated from 2 x 2
(1/2" mesh) stainless steel screen. Rodent screens and are installed as shown in Figure 7.28. Rodent screens ("bird guards")
for PolyPro, InnoFlue and Polyflue are as follows:
Size/Vent System
3" PolyPro
3" Polyflue
3" InnoFlue
If necessary to achieve required clearance above grade, CPVC or CPVC/PVC vent systems may be terminated using fittings
on snorkels as shown in Figure 7.12. When this is done, the equivalent length of all pipe on the exterior of the building,
except for the terminal fittings themselves, must be counted when calculating the equivalent length. The maximum vertical
run of the snorkel is 7 feet. Brace both the vent and inlet piping if required. PolyPro, InnoFlue and Polyflue may not be
snorkeled.
Terminal Option B: Ipex Low Profile Terminal (Acceptable for Vent Option 1) – This terminal is shown in Figure 7.7. If the
terminal is oriented vertically (alternate orientation shown in Fig 7.7) the exhaust opening must be on the top as shown. See
Section VII - E of this manual and the Ipex instructions provided with the terminal, for installation details.
Terminal Option C: DiversiTech "Low Profile" Terminal (Acceptable for Vent Option 1) – This terminal is shown in Figure
7.7. If the terminal is oriented vertically (alternate orientation shown in Fig 7.7) the exhaust opening must be on the top as
shown. See Section VII - E of this manual and the DiversiTech instructions provided with the terminal, for installation details.
Terminal Option D: Ipex FGV Concentric Terminal (Acceptable for Vent Option 1) - This terminal is shown in Figure 7.8
and may be used with CPVC/PVC vent systems. This terminal is available in various lengths and in both PVC and CPVC.
Terminals acceptable for use with these vent options are as follows:
See Section VII - E of this manual and the Ipex instructions provided with the terminal, for installation details.
Terminal Option E: DiversiTech Concentric Terminal (Acceptable for Vent Option 1) - This terminal is shown in Figure 7.8
and may be used with CPVC/PVC vent systems. See Section VII - E of this manual and the DiversiTech instructions provided
with the terminal, for installation details.
Terminal Option F: DuraVent PolyPro Concentric Terminal (Acceptable for Vent Option 2) - This terminal is shown in
Figure 7.10 and may be used with DuraVent 3" PolyPro vent systems. See Section VII - F of this manual and the DuraVent
instructions provided with the terminal, for installation details.
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B. Design Requirements Unique to Horizontal Twin Pipe Venting Systems (continued)
Rodent Screen ("Bird Guard")
DuraVent # 3PPS-BG
Selkirk # 3PV-HVST
Centrotherm # IASPP03
Ipex PN FGV Concentric Terminal Description
196006 3 x 20" PVC
196106 3 x 32" PVC
196116 3 x 44" PVC
197107 3 x 32" CPVC
197117 3 x 44" CPVC
107774-01 - 9/17