328767-001 www.
americanwaterheater .com 29
WATER
HEATER
MODEL
HEATER
INPUT
(Btu/hr)
VENT
SIZE
(Inside
Diam.)
2 PIPE MAX.
EQUIV. VENT
LENGTH
2 PIPE
MIN. EQUIV.
VENT LENGTH
CONC. VENT
MAX. EQUIV.
VENT LENGTH
CONC. VENT
MIN. EQUIV.
VENT LENGTH
40 gal.
40,000
2”
50’ + term. elbow
and screen*
7’ + term. elbow
and screen*
50’ + term. elbow
and screen*
7’ + term. elbow
and screen*
50 gal
45,000
40 gal.
40,000
3”
125’ + term. elbow
and screen*
7’ + term. elbow
and screen*
100’ + term. elbow
and screen*
7’ + term. elbow
and screen*
50 gal
45,000
50 gal.
58,000
3”
50’ + term. elbow
and screen*
30’ + term. elbow
and screen*
62,000
75 gal.
72,000
76,000
40 gal.
40,000
4”
180’ + term. elbow
and screen*
125’ + term. elbow
and screen*
N/A
N/A
50 gal
45,000
50 gal.
58,000
4”
125’ + term. elbow
and screen*
50’ + term. elbow
and screen*
62,000
75 gal.
72,000
76,000
* see Figure 28 and Figure 29
Equivalent lengths of straight pipe for various elbows using
Schedule 40 PVC, CPVC, ABS, and polypropylene.
Notes:
1. Vent lengths shown
do not
include vent termination
elbow.
2. A horizontal vent
must
have a 45° vent termination
elbow to direct the vent pipe downward.
3. A vertical vent
must
have a 90° elbow to direct the
vent pipe horizontally followed by a vent termination
45° elbow to direct the vent pipe downward.
4. If additional elbows are used in the vent system
the allowable vent lengths are reduced (see chart
below).
5. Two 45° elbows are considered the equivalent of
one 90° elbow.
6. The equivalent length of the sound suppressor is
similar to that of a short sweep 90° elbow.
Vent Pipe
Size
Elbow
Type
Short Sweep/
Radius
Long Sweep/
Radius
2”
3"
4"
90°
8’ 5’
2”
3"
4"
45°
4’ 2.5’
Table 3
Vent Pipe Termination
This water heater includes one (1) pair of more restrictive
Vent Termination Screens and one (1) pair of less
restrictive Vent Termination Screens. For safety and
optimum ef
fi
ciency performance, ensure the correct Vent
Termination Screen is installed for the vent length in your
installation.
Note:
Before installing the Power Direct Vent Water
Heater, it is recommended that the location of the pipe
terminations (air intake and exhaust vent) be determined.
Use the Vent Termination Screen as shown in Figure 28
& Figure 29. Install the Vent Termination Screen in the
Termination Elbow on both the air intake pipe and the
exhaust pipe.
