PB Heat Gas Boiler Venting, Inlet Air And Condensate, D.Exhaust Vent And Intake Air Pipe Sizing

VENTING, INLET AIR AND CONDENSATE

Figure 5.1: Location of exit terminals of mechanical draft and direct-vent venting systems.

(Reference: National Fuel Gas Code ANSI Z223.1/NFPA 54 2002).

Figure 5.2: Multiple Pinnacle Vent Spacing

D.EXHAUST VENT AND INTAKE AIR PIPE SIZING

1.For the PI-T50 and PI-T80 Boilers the exhaust vent and air intake pipes should be 2" Schedule 40 or 80.

2.For the PI-80, PI-140, PI-199 the exhaust vent and air intake pipes should be 3" Schedule 40 or 80.

3.The total combined equivalent length of exhaust vent and intake air pipe should not exceed 85 feet.

a.The equivalent length of elbows, tees, and other fittings are listed in Table 5.1.

b.For example: If the exhaust vent has two 90° elbows and 10 feet of PVC pipe we will calculate:

Table 5.1: Fitting Equivalent Length Table

Fitting Description	Equivalent Length
Elbow, 90°, Short Radius	5
Elbow, 45°, Short Radius	3
Coupling	0
Air Intake Tee	0
Concentric Vent Kit	3
V1000 & V500 Vent Kit	0

Exhaust Vent Pipe Equivalent Length = (2x5)+10=20 feet

Further, if the intake air pipe has two 90° elbows, one 45° elbow and 10 feet of PVC pipe, the following calculation applies:

Air Intake Pipe Equivalent Length = (2x5)+3+10=23 feet

Finally, if a concentric vent kit is used we find:

Total Combined Equivalent Length = 20+23+3=46 feet

Therefore, the total combined equivalent length is 46 feet which is well below the maximum of

85 feet.

c.The intake air pipe and the exhaust vent are intended to penetrate the same wall or roof of the building.

d.Effort should be made to keep a minimum difference in equivalent length between the air intake pipe and the exhaust vent.

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