Thermal Solutions APEX APX425C - 4 Venting (continued); Vent and Combustion Air Pipe Sizes and Lengths; Vent System and Combustion Air System Component Equivalent Length

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106308-05 - 3/23
APEX Installation, Operating, & Service Instructions
Table 4-2: Vent and Combustion Air Pipe Sizes and Equivalent Lengths
(Applies to All Listed Vent/Combustion Air System Options)
Component Equivalent Length
Nominal Diameter 3 in. (80 mm) 4 in. (100 or 110 mm) 6 in. (150 or 160 mm)
90° Elbow, Short Radius 10 ft. (3.0 m) 13 ft. (4.0 m) 22 ft. (6.7 m)
90° Elbow, Long Sweep/Sanitary 4.0 ft. (1.2 m) 9 ft. (2.7 m) 17 ft. (5.2 m)
45° Elbow 3.0 ft. (0.9 m) 4.5 ft. (1.4 m) 7.5 ft. (2.3 m)
Table 4-3: Vent System and Combustion Air System Component Equivalent Length
(Applies to All Listed Vent/Combustion Air System Options)
Table 4-4: Vent and Combustion Air Equivalent Length Calculation Worksheet
Component
Combustion Air Vent
Equivalent
Length Per
Piece
x Quantity =
Subtotal
Equivalent Length
Equivalent
Length Per
Piece
x Quantity =
Subtotal Equivalent
Length
Straight Pipe x = A E
90° Elbow,
Short Radius
x = B F
90° Elbow,
Long Sweep/
Sanitary
x = C G
45° Elbow x = D H
Combustion Air Total
Equivalent Length
= A+B+C+D
Vent Total
Equivalent Length
= E+F+G+H
Notes:
1. Total equivalent length cannot exceed maximum equivalent length shown in Table 4-2.
2. Use elbow equivalent lengths provided in Table 4-3.
3. Combustion air and vent terminations do not count towards total equivalent length.
4. Pressure drop for flexible polypropylene liner is 20% greater than for rigid pipe. Multiply measured flexible polypropylene liner
length by 1.2 to obtain equivalent length.
Example
Measured length = 35 ft.
Equivalent length =35 ft. x 1.2 = 42 ft.
5. Maximum equivalent length of flexible polypropylene liner is 48 ft. (14.6 m).
Boiler
Model
Option
Combustion Air Length Vent Length
Approx. Derate at Max.
Length(%)
Pipe Dia., in.
(mm)
Min., ft.
(m)
Max., ft.
(m)
Pipe Dia., in.
(mm)
Min., ft.
(m)
Max., ft.
(m)
APX425C
Standard
Diameter
4 (100 or 110) 0 100 (30.5) 4 (100 or 110) 2.5 (760) 100 (30.5) 5
Reduced
Diameter
3 (80) 0 50 (15.2) 3 (80) 2.5 (760 ) 50 (15.2 ) 5
APX525C
Standard
Diameter
4 (100 or 110) 0 100 (30.5) 4 (100 or 110) 2.5 (760) 100 (30.5) 11
Reduced
Diameter
3 (80) 0 50 (15.2) 3 (80) 2.5 (760) 50 (15.2 ) 12
APX625C
Standard
Diameter
4 (100 or 110) 0 100 (30.5) 6 (150 or 160) 2.5 (760) 200 (30.5) 7
Reduced
Diameter
4 (100 or 110) 0 50 (15.2) 4 (100 or 110) 2.5 (760) 50 (15.2 ) 10
APX725C
Standard
Diameter
4 (100 or 110) 0 100 (30.5) 6 (150 or 160) 2.5 (760) 200 (30.5) 11
Reduced
Diameter
4 (100 or 110) 0 50 (15.2) 4 (100 or 110) 2.5 (760) 50 (15.2 ) 15
APX825C
Standard
Diameter
4 (100 or 110) 0 100 (30.5) 6 (150 or 160) 2.5 (760) 200 (30.5) 14
Reduced
Diameter
4 (100 or 110) 0 50 (15.2) 4 (100 or 110) 2.5 (760) 50 (15.2 ) 15
4 Venting (continued)