User Guide

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
75 gal. 76,000
3”
50’ + term. elbow
and screen*
7’ + term. elbow
and screen*
30’ + term. elbow
and screen*
7’ + term. elbow
and screen*
4”
125’ + term. elbow
and screen*
50’ + term. elbow
and screen*
N/A N/A
* see Figure 29, “Venting Terminations And Sizing” and “Vent Screen Installation”.
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
3"
4"
90° 8’ 5’
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 effi 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 29.
Install the same Vent Termination Screen in the Termination
Elbow on both the air intake pipe and the exhaust pipe.
Venting Terminations And Sizing
• Refer to Table 3 for vent pipe materials and sizing. If
the installation requires a vent riser, suitable drainage
must be provided to ensure condensation does not
accumulate (see Figure 36). Termination through a roof
is shown Figure 23.
Vent Screen Installation
Installed in the vent termination elbow, the vent screen is
required to keep foreign objects, rodents and small birds
from entering the venting system. These screens have
been sized to ensure maximum energy effi ciency of the
vent system based on the “equivalent length” of the vent
piping. CHOOSE ONLY the ONE PAIR OF SCREENS
THAT MATCH YOUR VENTING CONFIGURATION (see
Figure 29). How to determine the “equivalent length” is
shown in Table 3.
• Supplied with this heater are several vent termination
screens (see Figure 29).
• Install the appropriate vent screen into the vent
termination elbow.
• Gently push the screen into the termination elbow until
it sits against the inside shoulder.
• The metal wire screens are self-securing.
• Plastic screens must be secured with (2) screws:
• Install plastic screen into elbow (see Figure 30).
• Orient screen as shown in see Figure 30 with an
opening at the bottom of the assembly and the
smooth side facing in.
• Ensure screen is fully seated against shoulder in
elbow.
• Secure screen in place with screws (fi eld supplied)
(see Figure 30).
Important: Failure to install the appropriate screen in the
vent termination elbows could result in improper heater
operation with attendant risk of property damage, personal
injury or death by fi re or carbon monoxide poisoning.