Alpine ALP080B Installation, Operating And Service Instructions page 20

iV. Venting
A. General Guidelines (continued)
Table 6B: Vent/Combustion Air Equivalent Length Calculation Work Sheet
Combustion air
90° Elbow(s) (installer Supplied)
Quantity
Nominal Diameter
3 in.
(80 mm)
4 in.
(100 mm or 110 mm)
45° Elbow(s) (installer Supplied)
Quantity
Nominal Diameter
3 in.
(80 mm)
4 in.
(100 mm or 110 mm)
Straight Pipe, (installer Supplied)
Quantity
Nominal Diameter Length,
ft or m
3 in.
(80 mm)
4 in.
(100 mm or 110 mm)
* Total Equivalent Length (A+B+C) =
* notes:
1. Calculated total equivalent length cannot exceed
maximum equivalent length shown in Table 5.
2. Vent and combustion air terminals do not count towards
total equivalent length.
3. 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
Measure length of flexible polypropylene liner = 35 ft.
Equivalent length of flexible polypropylene liner = 35 ft.
x 1.2 = 42 ft.
4. Maximum equivalent length of flexible polypropylene liner
is 48 ft. (14.6 m).
5. All elbows referenced are short radius.
a. Use only listed vent/combustion air terminals.
i.
Horizontal Sidewall Venting: For models
ALP080B and ALP285B, use tee terminals
for both vent and combustion air as shown
in Figure 5. Alternate snorkel terminations
are shown in Figure 6A and Figure 6B.
ii. Vertical Roof Venting: Use straight
coupling on vent and two 90° elbows turned
downwards for combustion air as shown in
Figure 7 and Figure 8.
b. Maintain correct clearance and orientation
between vent and combustion air terminals.
i. Space centerlines of vent and combustion
air terminals minimum 12 in. (300 mm)
apart. More than 12 in. (300 mm) spacing is
recommended.
20
Subtotal,
Equivalent
Equivalent
(Pc) Length, per Pc
Length (A)
10 ft. (3.0 m)
13 ft. (4.0 m)
Equivalent
Equivalent
(Pc) Length, per Pc
Length (B)
3.0 ft. (.09 m)
4.5 ft. (1.4 m)
Equivalent
Length, Equivalent
ft/ft or m/m Length (C)
1
1
90° Elbow(s) (CPVC Supplied with Boiler)
Nominal Diameter
3 in.
(80 mm)
4 in.
(100 mm or 110 mm)
90° Elbow(s) (installer Supplied)
Subtotal,
Nominal Diameter
3 in.
(80 mm)
4 in.
(100 mm or 110 mm)
45° Elbow(s) (installer Supplied)
Subtotal,
Nominal Diameter
3 in.
(80 mm)
4 in.
(100 mm or 110 mm)
2.5 Ft. (760 mm) Straight Pipe, (CPVC Supplied with Boiler)
Nominal Diameter
3 in.
(80 mm)
4 in.
(100 mm or 110 mm)
Nominal Diameter
3 in.
(80 mm)
4 in.
(100 mm or 110 mm)
* Total Equivalent Length (A+B+C+D+E) =
Figure 5: Direct Vent - Sidewall Tee Terminations
Vent
Quantity Equivalent Length,
(Pc) per Pc
1 10 ft. (3.0 m)
1 13 ft. (4.0 m)
Quantity Equivalent Length,
(Pc) per Pc
10 ft. (3.0 m)
13 ft. (4.0 m)
Quantity
Equivalent Length,
Length,
ft/ft or m/m
ft or m
3.0 ft. (.09 m)
4.5 ft. (1.4 m)
Quantity
Equivalent Length,
Length,
ft/ft or m/m
ft or m
2.5 ft.
1
(0.76 m)
2.5 ft. 1
(0.76 m)
Straight Pipe, (installer Supplied)
Quantity
Equivalent Length,
Length,
ft/ft
ft
1
1
Subtotal,
Equivalent
Length (D)
10 ft. (3.0 m)
13 ft. (4.0 m)
Subtotal,
Equivalent
Length (A)
Subtotal,
Equivalent
Length (B)
Subtotal,
Equivalent
Length (E)
2.5 ft.
(0.76 m)
2.5 ft.
(0.76 m)
Subtotal,
Equivalent
Length (C)
103448-06 - 4/15