Burnham Water boiler Installation, Operating And Service Instructions page 24

iV. Venting (continued)
Table : Vent/Combustion air Pipe Length – Two-Pipe Direct Vent System Options (CPVC/PVC and Stainless
Steel/PVC or galvanized Steel)
3" Combustion Air Pipe
Boiler
(Equivalent Length)
Model
Min.
ALP080 30 In.
ALP105 30 In.
ALP150 ---
ALP210 ---
ALP285 ---
ALP399 ---
ALP500 ---
Vent/Combustion Air, Equivalent Length Work Sheet
This sheet is supplied to assist in vent/combustion air, equivalent length calculating
Combustion air
90° elbow(s) PVC
Quantity =
45° elbow(s) PVC
Quantity =
Straight pipe PVC
Length ft. =
Total*
* Total cannot exceed 60 equiv. ft. length.
Vent and combustion air terminals do not count towards total equiv. ft.
Figure 6a: near-Boiler Vent/Combustion air Piping - Floor Mounted Boiler Builds
2
4" Combustion Air Pipe
(Equivalent Length)
Max.
Min.
100 Ft. ---
100 Ft. ---
--- 30 In.
--- 30 In.
--- 30 In.
--- 30 In.
--- 30 In.
x 5 = equiv. ft. a.
x 2.5 = equiv. ft. b.
x 1 = equiv. ft. c.
a.+b.+c. = equiv. ft.
3" Vent Pipe
(Equivalent Length)
Max.
Min.
--- 30 In.
--- 30 In.
100 Ft. 30 In.
100 Ft. 30 In.
60 Ft. ---
60 Ft. ---
60 Ft. ---
Supplied 30" straight CPVC
Length ft. = 2.5
Supplied 90° elbow CPVC
Quantity = 1
90° elbow(s) PVC
Quantity =
45° elbow(s) PVC
Quantity =
Straight pipe PVC
Length ft. =
Total* a.+b.+c.+d.+e.=
4" Vent Pipe
(Equivalent Length)
Max.
Min.
100 Ft. ---
100 Ft. ---
100 Ft. ---
100 Ft. ---
--- 30 In.
--- 30 In.
--- 30 In.
Vent
x 1 = 2.5 equiv. ft. a.
x 5 = 5 equiv. ft. b.
x 5 = equiv. ft. c.
x 2.5 = equiv. ft. d.
x 1 = equiv. ft. e.
equiv. ft.
Max.
---
---
---
---
60 Ft.
60 Ft.
60 Ft.