A.O. Smith VB/VW-500 - Manual (Page 13)

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from the horizontal to vertical run. This is where the bottom most
support bracket should be located.
The Boot-Tee Drain Cover is required in order to dispose of
the condensate from the venting system. The plastic tube
(3/8 [9mm] ID, 10 feet [3m] long) needed to route the condensate
to a suitable drain is provided with the boiler.
1. Attach the Boot Tee Drain Cover to the appropriate leg of the
Boot-Tee, see Figure 10.
2. A trap loop must be formed into the drain tube simply by looping
the tube to a minimum 3 inch (76mm) diameter and secure the
loop with a cable tie, see Figure 10.
3. Prior to final assembly the trap loop must be “primed” by pouring
a small quantity of water into the drain hose.
4. Connect the Boot-Tee and Drain Tee assembly to the boiler
vent connector, see Figure 10.
5. Attach the hose to the drain fitting and run the hose to a sanitary
sewer drain maintaining the proper trap loop and following all
local, state and federal codes and regulations for draining of
acidic effluent (condensate).
Figure 10.
VENTING SUPPORTS
Care must be taken in the installation of the venting system that
adequate support is maintained throughout the installation process.
When extending more than 10 feet (3.0m) vertically, vertical support
kits are required once every 10 feet (3.0m) of vertical run. Vertical
support is also required immediately after any transition (elbow,
tee, etc.) to vertical of over 10 feet (3.0m) of run and after any
offset in the vertical run.
The support brackets (supplied in the Vertical Support Kit) are to be
securely fastened to a solid vertical member of the building using the
appropriate fasteners; i.e., wood screws for wood framing, machine or
tapping screws for structural steel or masonry anchors for solid masonry.
The bracket should be located so that it will not interfere with any joints
of the venting system. The bottom most support bracket should be
located directly above the first transition from horizontal to vertical, see
Figure 10. Refer to Figures 12, 12A, 12B and 12C.
If a means of support for the brackets are not available and
horizontal vent sections are present, install hanger straps
(made from non-combustible material) as close to the points of
transition as possible. If the horizontal portions of the vent and/or
vent connector are longer than 6 feet (2.0m), then install hanger
straps every 6 feet (2.0m) to support the connector.
DO NOT rivet or screw the straps to the conduit or otherwise
puncture the conduit wall. Instead, wrap an extra loop of strap
around the conduit to hold it in position, or attach the strap to the
center screw of the double wall AL 29-4C
® vent coupling, if applicable.
VERTICAL INSTALLATION REQUIREMENTS
1. The vent system must terminate at least 3 feet (1.0m) and
no more than 6 feet (2.0m) above the roof line and no
closer than 10 feet (3.0m) from any wall or vertical
structure. If the exhaust vent terminal is within 10 feet
(3.0m) of a wall or parapet, it must extend a minimum of
2 feet (610mm) above the wall or parapet, see Figures 11
and 12A.
2. For direct vent installations, the total distance of the vent system
from the boiler vent connector to the vertical vent termination shall
not exceed 70 equivalent feet (21.3m). A maximum of three 90°
elbows can be used. Minimum vertical vent is 7 equivalent feet (2.1m)
for direct vent installations. Standard minimum vertical vent length is
7 feet (2.1m), plus Boot-Tee. See Figures 11, 12A, 12B, and 12C for
differences between standard and direct vent installations.
3. An AL 29 - C ® Vent Vertical Vent Terminal must be used at
the termination.
4. Maintain a minimum of 6 feet (2.0m) separation between
the air intake and the exhaust terminals.
HORIZONTAL INSTALLATION REQUIREMENTS
1. The vent system must terminate with a AL 29-4C ® Vent
Through-the-Wall Termination (TWT). Plan the terminal
location based on the dimensions shown in Figure 9. Do
not locate the terminal within 8 feet (2.5m) of an inside
corner of a building or adjacent to outside walls, shrubs or
other such objects that may cause adverse wind conditions
in the immediate area.
2. The TWT shall be located not less than 12 inches (305mm)
above grade or, in geographical areas where snow
accumulates, no less than 12 inches (305mm) above the
anticipated snow line. Ensure that the TWT is protected
against blockage which may occur during ice buildup or
snowstorms.
The TWT shall terminate at least 3 feet (1.0m) above any
forced air inlet within 10 feet (3.0m), except when the
forced air inlet is the combustion air intake of a direct vent
appliance. The TWT shall terminate at least 4 feet (1.2m)
below, 4 feet (1.2m) horizontally from or 1 foot (305mm)
above any door, window or gravity air inlet into any building
as provided in the current edition of the NATIONAL FUEL
GAS CODE ANSI Z223.1, see Figure 9.
In addition, a minimum clearance of 4 feet (1.2m)
horizontally from, and in NO CASE ABOVE OR BELOW,
unless the 4 feet (1.2m) of horizontal distance is maintained
from electric meters, gas meters, regulators and relief
equipment.
3. This horizontal exhaust vent system must pitch upward toward
the termination at 1/4 inch per foot (21mm per meter).
4. The TWT is designed such that the building is protected
from degradation by flue gas and condensate. However, if
additional protection is desired, install against the wall a
non-corrosive metal sheet under the TWT.
5. Due to the normal formation of water vapor in the combustion
process, horizontal terminations must not be located over
areas of pedestrian or vehicular traffic, (i.e., public walkways
or over areas where condensate could create a nuisance or
hazard). This is especially true in colder climates where ice
buildup is likely to occur. A.O. Smith Corporation will not be
held liable for any personal injury or property damage due
to any dislodging of ice.