A.O. Smith 100 Series Installation And Operating Manual page 20

SIDE WALL VENT TERMINATION (STANDARD)
Important: When terminating the vent on a side wall, the
following specifications pertaining to terminal
location must be followed. See Figure 16.
1. The air intake terminal and the exhaust vent terminal must
terminate on the same exterior wall.
2. The vertical centerline of the air intake terminal must be located
at a minimum of 200 mm (8") from the vertical centerline of the
exhaust vent terminal.
3. The horizontal centerline of the air intake terminal may not be
located more than 610 mm (24") below the horizontal centerline
of the exhaust vent terminal.
4. To avoid exhaust recirculation, the air intake terminal may be
rotated away from the exhaust vent terminal. See Figure 16.
SIDE WALL
EXHAUST
VENT
TERMINAL
Figure 16. Sidewall Vent Clearances
ROOF VENT TERMINATION (STANDARD)
Important: When terminating the vents through a roof, the
following specifications pertaining to terminal
location must be followed. See Figure 17.
200 mm
(8") Min.
A & B; ABOVE
ANTICIPATED SNOW LEVEL
OR 450 mm (18")
MIN. ABOVE ROOF
EXHAUST
VENT
TERMINAL
Figure 17. Roof Vent Snow Clearances
200 mm
(8") MIN.
610 mm
(24") MAX.
INTAKE
VENT
TERMINAL
25 mm
(1")
INTAKE
VENT
25 mm
TERMINAL
(1")
B
A
1. The air intake termination and the exhaust vent termination
shall extend above anticipated snow level or at least450 mm
(18") above the roof.
2. Must provide proper support for all pipes protruding through roof.
3. The vertical roof terminations should be sealed with a plumbing
roof boot or equivalent flashing.
4. The air intake termination and the exhaust vent termination must
penetrate the same side of roof.
5. The centerline of the air intake termination and the centerline
of the exhaust vent termination must not be closer than 200
mm (8").
6. The air intake terminal and the exhaust vent terminal must be
oriented facing downward and the same direction.
SIDE WALL VENT FOR COLD CLIMATES
Some winter weather conditions present a risk of ice accumulation
at the intake termination screen. Such accumulation will restrict
intake air flow. If local conditions present this risk, the termination
configuration shown in Figure 18 is recommended. This will reduce
the possibility of exhaust gas recirculation as well as reduce the
chance of ice accumulation.
If necessary to avoid snow accumulation, the intake vent terminal
may be fitted with a riser similar to that on the exhaust vent terminal.
Both the intake and exhaust vent terminations may be 90° elbows if
specified by local requirements.
Note: The vertical centerline of the air intake termination and the
vertical centerline of the exhaust vent termination must not
be closer than 200 mm (8").
Important: Elbows (excluding the termination elbow) and
risers must be considered when calculating total
equivalent vent length. See Table 6 (page 16).
EXHAUST
TERMINAL
VENT
SCREEN
INSIDE
WALL
MOUNTED
SUPPORT
BRACKET
INTAKE
TERMINAL
300mm (12")
ABOVE GRADE
OR ABOVE
ANTICIPATED
SNOW LEVEL
Figure 18. Sidewall Vent Termination Snow Clearances
Debris screens may be removed while there is a risk of ice
accumulation but this can make the air intake susceptible to debris
buildup, the entry of birds, other small animals or rodents. If the debris
screens are removed to prevent ice accumulation, it is recommended
that they be re-installed when the risk of ice accumulation has
passed.
20
200mm
(8") MIN.
610mm
(24")
MAX.
VENT
SCREEN