9
TNR-I&S-02
Through The Wall Venting with Low Ground Clearance:
When venting cannot exit through the wall at a height greater than or
equal to 12"
(30.5 cm)
(and above expected snow level) from the ground,
then the installation must be modified as shown below (see Figure 13).
Determining required vent length:
1. Determine the total length of straight vent pipe (in feet) required
for both the intake and the exhaust.
2. Add 5 feet of venting for every 90° elbow.
3. Add 2 ½ feet of venting for every 45° elbow.
4.
Total vent length can not exceed “Max Vent Length” in
Table 2.
5.
Air intake can not exceed exhaust by more than 30 feet in
any venting situation.
POWER VENT INSTALLATION
Power venting is where the indoor air is used and the exhaust is vented to
the outside. Venting may be run horizontally through an outside wall or
vertically through a roof through using either 3 inch
(7.6 cm)
or 4 inch
(10.2 cm)
diameter PVC or CPVC. This water heater is supplied with a
screened intake and exhaust 90° elbow referred to as the exhaust vent
terminal and the air intake terminal.
Power Vent Terminal Location
Refer to the “Direct Vent Terminal Location” (see page 7) section
previously mentioned to determine the proper exhaust vent location.
Plan the vent system layout so that proper clearances are maintained
from plumbing and wiring. Vent pipes serving power vented appliances
are classified by building codes as “vent connectors”. Required
clearances from combustible materials must be provided in accordance
with information in this manual under LOCATION OF WATER HEATER
and CLEARANCES, and with National Fuel Gas Code and local codes.
Figure 13
Vent Terminal (Low Ground Clearance)
NOTICE
DO NOT
include the 3" exhaust elbow or vent terminals in
determining maximum vent length.
Table 2
Direct Vent Maximum Vent Length
Storage
Capacity
(Gallons)
Rated
Input
(BTU/HR)
Max Vent Length (ft)
3" PVC or CPVC
Max Vent Length (ft)
4" PVC or CPVC
6 0
6 0
6 0
1 0 0
1 0 0
1 0 0
1 0 0
1 0 0
125,000
150,000
199,000
150,000
199,999
250,000
300,000
399,999
1 2 0
1 0 0
8 0
1 2 0
1 0 0
8 0
6 0
5 0
1 7 0
1 5 0
1 3 0
1 7 0
1 5 0
1 3 0
1 1 0
1 0 0
Figure 12
Typical Vertical Direct Vent System Installation
