Combustion Air Pipe Sizing - Watts Aerco Modulex EXT Series Technical Application Manual

Modulex EXT Vent and Combustion Air Application Guide
Bird Screen
Installed
Figure 8: Outdoor Installation Air Inlet and Vent Outlet Locations
11. For outdoor installations, an outdoor venting kit is available through AERCO. Please contact your
local representative for further details.

2.2. COMBUSTION AIR PIPE SIZING

The maximum length is the combined length of straight horizontal and vertical runs, and the
equivalent straight length of fittings. The required lengths for each boiler are shown in Table 3, below.
TABLE 3: Maximum Combustion Air Run Lengths
PIPE
MODEL NO.
DIAM.
EXT 321
EXT 481/450 (102
EXT 641/600 mm)
EXT 802/800
EXT 962 (152
EXT 1123/1100 mm)
10"
EXT 1530/1500
(254
EXT 1912
mm)
12"
EXT 2295/2300
EXT 2677/2600
(305
EXT 3060/3000
mm)
The maximum pressure drop of the vent is also 100 equivalent feet (30.5 m). See Section 3.4. Note
that this does NOT mean the allowed combined pressure drop between the vent and combustion air is
200 equivalent feet (61 m). That is, the vent cannot go above 100 equivalent feet (30.5 m), even if the
combustion air is less than 100 equivalent feet, and vice versa.
Page 12 of 28
09/25/2017
EQUIVALENT PIPE LENGTHS EXAMPLES
Sharp 90°
Elbow
Equiv. Ft (m)
4"
10 ft.
(3.05 m)
6"
10 ft.
(3.05 m)
10 ft.
(3.05 m)
10 ft.
(3.05 m)
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Phone: 800-526-0288
Sweep 90°
45° Elbow
Elbow
Equiv. Ft (m)
Equiv. Ft (m)
5 ft. 5 ft.
(1.5 m) (1.5 m)
5 ft.
N/A
(1.5 m)
5 ft.
N/A
(1.5 m)
5 ft.
N/A
(1.5 m)
MAXIMUM
LENGTH
EQUIVALENT
FT (M)
100 ft.
(30.5 m)
100 ft.
(30.5 m)
100 ft.
(30.5 m)
100 ft.
(30.5 m)
TAG-0054-0F
GF-136-V