8
BURNERS AND FLUE TUBES AND CREATES A RISK OF
ASPHYXIATION.
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
9 and 10.
This water heater must be vented in compliance with all local
codes, the current revision 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 9 and 10 should be used for
horizontally manifolding two or more heaters.
FIGURE 7
