User Guide

C. Design Requirements Unique to Vertical Venting Systems

Table 7.11 summarizes all vertical twin pipe vent options. In addition to the requirements in Part VII-A, observe the

following design requirements:

1. Permitted Terminals for Vertical Venting

Terminal Option H: Fittings –Ventterminatesinaplainend(couplingforPVC.IntaketerminatesinaPVC180elbow

pointingdown(twosweep90’smaybesubstituted).Observetheclearancesfromtheroof,andnormalsnowlineontheroof,

shown in Figures 7.12 and 7.13.

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. They are installed as shown in Figure 7.18.

Terminal Option I: Ipex FGV Concentric Terminal - This terminal is shown in Figure 7.13 and may be used with CPVC/PVC

ventsystems.UseacompatibleroofashingandstormcollarinaccordancewiththeIpexinstructionsforthisterminal.This

terminal is available in various lengths and in both PVC and CPVC. Terminals acceptable for use with these vent options are

as follows:

Ipex PN FGV Concentric Terminal Description

196005 2 x 16” PVC

196105 2 x 28” PVC

196125 2 x 40” PVC

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

See Part VII-E of this manual and the Ipex instructions provided with the terminal, for installation details.

Terminal Option J: Diversitech Concentric Terminal - This terminal is shown in Figure 7.13 and may be used with CPVC/

PVC vent systems. See Part VII-E of this manual and the Diversitech instructions provided with the terminal, for installation

details.

2. Vertical Vent and Air Intake Location–Observethefollowingclearancesfromroofmountedterminals:

 • Bottomofairintakeopeningmustbeatleast12”abovethenormalsnowlineanticipatedontheroof.

 • Exhaustopeningmustbeatleast2ftaboveanyportionoftherooforstructurelocatedwithinhorizontallywithin10ft.

 • ForterminaloptionH,maintainatleast12”ofverticalseparationbetweentheexhaustandintakeopeningasshownin

Figure 7.12.

NOTICE

Vertical venting and combustion air roof penetrations (where applicable) require the use of roof

ashing and storm collar, which are not supplied with the boiler, to prevent moisture from entering the

structure.