Install Instructions
26 103448-02 - 6/13
IV. Venting B. CPVC/PVC Venting (continued)
Table 8: Vent/Combustion Air Pipe Length – Two-Pipe Direct Vent System Options
• CPVC/PVC
• Polypropylene (PP) or Polypropylene (PP)/PVC
• Stainless Steel/PVC or Galvanized Steel)
Boiler
Model
3” (80 mm)
Combustion Air Pipe
(Equivalent Length)
4” (100 mm)
Combustion Air Pipe
(Equivalent Length)
3” (80 mm) Vent Pipe
(Equivalent Length)
4” (100 mm) Vent Pipe
(Equivalent Length)
Min. Max. Min. Max. Min. Max. Min. Max.
ALP080B 30 In. 135 Ft. 30 In. 135 Ft.
ALP105B 30 In. 135 Ft. 30 In. 135 Ft.
ALP150B 30 In. 135 Ft. 30 In. 135 Ft.
ALP210B 30 In. 135 Ft. 30 In. 135 Ft.
ALP285B 30 In. 100 Ft. 30 In. 100 Ft.
ALP399 30 In. 100 Ft. 30 In. 100 Ft.
Vent/Combustion Air Equivalent Length Calculation Work Sheet CPVC/PVC Two-Pipe
Combustion Air Vent
90° Elbow(s) PVC (Installer Supplied) 90° Elbow(s) CPVC (Supplied with Boiler)
Nominal
Diameter, In.
Quantity
(Pc)
Equivalent
Length, Ft/Pc
Subtotal,
Equivalent
Ft. (A)
Nominal
Diameter, In.
Quantity
(Pc)
Equivalent Length,
Ft/Pc
Subtotal,
Equivalent Ft.
(D)
3 10 3 1 10 10
4 13 4 1 13 13
45° Elbow(s) PVC (Installer Supplied) 90° Elbow(s) PVC (Installer Supplied)
Nominal
Diameter, In.
Quantity
(Pc)
Equivalent
Length, Ft/Pc
Subtotal,
Equivalent
Ft. (B)
Nominal
Diameter, In.
Quantity
(Pc)
Equivalent Length,
Ft/Pc
Subtotal,
Equivalent Ft.
(A)
3 3.0 3 10
4 4.5 4 13
Straight Pipe, PVC (Installer Supplied) 45° Elbow(s) PVC (Installer Supplied)
Nominal
Diameter, In.
Quantity
(Length, Ft.)
Equivalent
Length, Ft/Ft
Subtotal,
Equivalent
Ft. (C)
Nominal
Diameter, In.
Quantity
(Length, Ft.)
Equivalent Length,
Ft/Ft
Subtotal,
Equivalent Ft.
(B)
3 1 3 3.0
4 1 4 4.5
* Total Equivalent Length, Ft. (A+B+C) = 30” (2.5 Ft.) Straight Pipe, CPVC (Supplied with Boiler)
Nominal
Diameter, In.
Quantity
(Length, Ft.)
Equivalent Length,
Ft/Ft
Subtotal,
Equivalent Ft.
(E)
3 2.5 1 2.5
4 2.5 1 2.5
Straight Pipe, PVC (Installer Supplied)
Nominal
Diameter, In.
Quantity
(Length, Ft.)
Equivalent Length,
Ft/Ft
Subtotal,
Equivalent
Ft. (C)
3 1
4 1
* Total Equivalent Length, Ft. (A+B+C+D+E) =
* Note: Total Equivalent Length Calculated Value Cannot Exceed Max. Equivalent Length Values shown in Table 8.
Vent and Combustion Air Terminals Do Not Count Towards Total Equivalent Length.