American Water Heater ABCG3 - Manual (Page 9)

9
Where an exhaust fan is supplied in the same room with a
heater, sufficient openings for air must be provided in the
walls.
UNDERSIZED OPENINGS WILL CAUSE AIR TO BE
DRAWN INTO THE ROOM THROUGH THE CHIMNEY,
CAUSING POOR COMBUSTION. SOOTING MAY RESULT IN
SERIOUS DAMAGE TO THE HEATER AND RISK OF FIRE OR
EXPLOSION.
UNCONFINED SPACE
In buildings of conventional frame, brick, or stone construction,
unconfined spaces may provide adequate air for combustion,
ventilation and draft hood dilution.
If the unconfined space is within a building of tight construction
(buildings using the following construction: weather stripping,
heavy insulation, caulking, vapor barrier, etc.), air for combustion,
ventilation and draft hood dilution must be obtained from outdoors.
The installation instructions for confined spaces in tightly
constructed buildings must be followed to ensure adequate air
supply.
CONFINED SPACE
When drawing combustion and dilution air from inside a
conventionally constructed building to a confined space,
such a space shall be provided with two permanent
openings, ONE IN OR WITHIN 12 INCHES (30.5cm) OF
THE ENCLOSURE TOP AND ONE IN OR WITHIN 12 INCHES
(30.5cm) OF THE ENCLOSURE BOTTOM. Each opening
shall have a free area of at least one square inch per 1000
Btuh (2,225mm
2 /Kw) of the total input of all appliances in
the enclosure, but not less than 100 square inches (645
square cm).
If the confined space is within a building of tight construction,
air for combustion, ventilation, and drafthood dilution must be
obtained from outdoors. When directly communicating with
the outdoors or communicating with the outdoors through
vertical ducts, two permanent openings, located in the above
manner, shall be provided. Each opening shall have a free
area of not less than one square inch per 4000 Btuh
(8,900mm
2 /Kw)of the total input of all appliances in the
enclosure. If horizontal ducts are used, each opening shall
have a free area of not less than one square inch per 2000
Btuh (4,450mm
2 /Kw)of the total input of all appliances in the
enclosure.
VENTING
WARNING
THE INSTRUCTIONS IN THIS SECTION ON VENTING MUST
BE FOLLOWED TO AVOID CHOKED COMBUSTION OR
RECIRCULATION OF FLUE GASES. SUCH CONDITIONS
CAUSE SOOTING OR RISKS OF FIRE AND ASPHYXIATION.
Heater must be protected from freezing downdrafts.
Remove all soot or other obstructions from the chimney that will
retard a free draft.
Type B venting is recommended with these heaters. For typical
venting application see TECHNICAL DATA VENTING on pages
10 and 11.
This water heater must be vented in compliance with all local
codes, the current edition of the National Fuel Gas Code (ANSI-
Z223.1) and with the Category I Venting Tables.
If any part of the vent system are exposed to ambient
temperatures below 40°F it must be insulated to prevent
condensation.
• Do not connect the heater to a common vent or chimney with
solid fuel burning equipment. This practice is prohibited by
many local building codes as is the practice of venting gas
fired equipment to the duct work of ventilation systems.
FIGURE 6
• Where a separate vent connection is not available and the
vent pipe from the heater must be connected to a common
vent with an oil burning furnace, the vent pipe should enter
the smaller common vent or chimney at a point above the
large vent pipe.
MULTIPLE HEATER MANIFOLD
Figure 7 and tables on pages 10 and 11 should be used for
horizontally manifolding two or more heaters.
FIGURE 7