Bradford White eF Series Installation & Operation Manual With Troubleshooting Manual page 26

Venting continued-
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 ft of venting for every 90° elbow.
3. Add 2 1/2 ft of venting for every 45° elbow.
Total vent length cannot exceed "Max Vent Length" in Table 3.
4.
5. Air intake cannot exceed exhaust by more than 30 ft in any venting situation.
Example of Total Direct Vent Length for 100T199
A 3 in venting system has a total of six 90° elbows and a total straight pipe length of 65 ft (includes both intake and exhaust
pipe). Equivalent vent length for elbows: 6 x 5 ft = 30 ft. Total equivalent vent distance = 65 ft + 30 ft = 95 ft total equivalent
vent length. This is below the maximum allowed distance of 100 ft for this model using 3 in vent.
Example Of Total Vent Length For 100T199 With A Power Vented Installation
A 3 in venting system has a total of six 90° elbows and a total straight pipe length of 55 ft. Equivalent vent length for elbows: 6 x
5 ft = 30 ft. Total equivalent vent distance = 55 ft + 30 ft = 85 ft total equivalent vent length. This is below the maximum
allowed distance of 100 ft for this model using 3 in vent.
DO NOT include the 3 in (7.6 cm) condensate elbow or vent terminals in determining maximum vent length.
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 2 in (5.1 cm), 3 in (7.6 cm), 4 in (10.2 cm), or 6 in
(15.2 cm) diameter pipe. This water heater is supplied with a 3 in (7.6 cm) diameter screened intake elbow and exhaust
coupling referred to as the air intake terminal and the exhaust vent terminal.
Power Vent Terminal Location
Refer to the "Direct Vent Terminal Location" 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.
Clearance to combustibles for all venting pipes and terminals
For installations in the US
DO NOT place insulation or other materials in the required clearance spaces between the venting to combustible
material unless otherwise specified.
Horizontal Installation
In a horizontal application, it is important that condensate not be allowed to buildup in the exhaust vent pipe. To prevent
this from happening, the pipe should be installed with a slight upward slope of 1/4 in/ft. The vent system must be
supported every 5 ft (1.5 m) of vertical run and every 3 ft (.92 m) of horizontal run of vent pipe length.
Failure to properly support the vent piping with hangers and clamps may result in
Stress levels in the pipe and fittings can be significantly increased by improper installation. If rigid pipe clamps are used to
hold the pipe in place, or if the pipe cannot move freely through a wall penetration, the pipe may be directly stressed, or
high thermal stresses may be formed when the pipe heats up and expands. Install accordingly to minimize such stresses.
Follow the following procedure to vent through the wall:
1. Cut one 2 3/8 in (6 cm), diameter hole (for 2 in (5.1 cm) diameter pipe), one 3 1/2 in (8.9 cm) diameter hole (for 3 in
(7.6 cm) diameter pipe) one 4 1/2 in (11.5 cm) diameter hole (for 4 in (10.2 cm) diameter pipe) or one 6 5/8 in (15.5
cm) diameter hole (for 6 in (15.5 cm) diameter pipe).
2. Use the proper cement or sealant to secure the exhaust vent terminal provided with the water heater to the plastic
pipes. The distance between the back edge of the exhaust vent terminal and the exterior wall (see Figure 15) must be
6 in (15.2 cm). Use the proper cement and assembly procedures to secure the vent connector joints between the
terminal and the blower outlet. Provide support brackets for every 3 ft (1 m) of horizontal vent.
0" minimum
damage to the water heater or venting system.
NOTICE
For installations in the CANADA
Refer to vent pipe and terminal manufacturer's
installation instructions for clearances to combustibles.
CAUTION
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