Air Requirements; Mechanical Exhausting Of Room Air; Unconfined Space; Confined Space - A.O. Smith CYCLONE XHE BTH 300A Installation & Operating Instructions Manual

See MAINTENANCE section for details of tank cleanout procedure.

AIR REQUIREMENTS

KEEP APPLIANCE AREA CLEAR AND FREE OF COMBUSTIBLE
MATERIALS, GASOLINE AND OTHER FLAMMABLE VAPORS
AND LIQUIDS.
DO NOT OBSTRUCT THE FLOW OF COMBUSTION AND
VENTILATING AIR.
FOR SAFE OPERATION PROVIDE ADEQUATE AIR FOR
COMBUSTION AND VENTILATION. AN INSUFFICIENT SUPPLY
OF AIR WILL CAUSE RECIRCULATION OF COMBUSTION
PRODUCTS RESULTING IN CONTAMINATION THAT MAY BE
HAZARDOUS TO LIFE. SUCH A CONDITION OFTEN WILL RESULT
IN A YELLOW, LUMINOUS BURNER FLAME, CAUSING CARBONING
OR SOOTING OF THE COMBUSTION CHAMBER, BURNERS AND
FLUE TUBES AND CREATES A RISK OF ASPHYXIATION.

MECHANICAL EXHAUSTING OF ROOM AIR

Where an exhaust fan is installed 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 HEATER'S VENTING SYSTEM,
CAUSING POOR COMBUSTION. SOOTING MAY RESULT IN
SERIOUS DAMAGE TO THE HEATER AND RISK OF FIRE OR
EXPLOSION. IT CAN ALSO CREATE A RISK OF ASPHYXIATION.

UNCONFINED SPACE

In buildings of conventional frame, brick or stone construction,
unconfined spaces may provide adequate air for combustion and
ventilation.
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 and
ventilation 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 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 (31 cm) OF THE ENCLOSURE TOP AND ONE IN OR
WITHIN 12 INCHES (31 cm) OF THE ENCLOSURE BOTTOM.
Each opening shall have a free area of at least one square inch per
2
1000 Btuh (2,203mm /kW) appliances in the enclosure, but not
less than 100 square inches (645 cm²).
If the confined space is within a building of tight construction, air for
combustion and ventilation must be obtained from outdoors. When
directly 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
2
per 4000 Btuh (551mm /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
2000 Btuh (1,102mm 2 /kW) of the total input of all appliances in the
enclosure.
WARNING
than one square inch

CHEMICAL VAPOR CORROSION

CORROSION OF THE FLUE WAYS AND VENT SYSTEM MAY
OCCUR IF AIR FOR COMBUSTION CONTAINS CERTAIN
CHEMICAL VAPORS. SUCH CORROSION MAY RESULT IN
FAILURE AND RISK OF ASPHYXIATION.
Spray can propellants, cleaning solvents, refrigerator and air
conditioning refrigerants, swimming pool chemicals, calcium and
sodium chloride, waxes, and process chemicals are typical
compounds which are potentially corrosive.
PRODUCTS OF THIS SORT SHOULD NOT BE STORED NEAR
THE HEATER. ALSO, AIR WHICH IS BROUGHT IN CONTACT
WITH THE HEATER SHOULD NOT CONTAIN ANY OF THESE
CHEMICALS. IF NECESSARY, UNCONTAMINATED AIR SHOULD
BE OBTAINED FROM REMOTE OR OUTSIDE SOURCES.
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 during shutdown
periods.
NEVER OPERATE THE HEATER UNLESS IT IS VENTED TO THE
OUTDOORS AND HAS ADEQUATE AIR SUPPLY TO AVOID
RISKS OF IMPROPER OPERATION, FIRE, EXPLOSION OR
ASPHYXIATION.

VENT PIPE TERMINATION

NOTE: Before installing venting, determine place of vent pipe
termination. See Figure 5 and 6 before proceeding.
DO NOT TERMINATE THE VENTING WHERE NOISE FROM THE
EXHAUST OR INTAKE WILL BE OBJECTIONABLE. THIS
INCLUDES LOCATIONS CLOSE TO OR ACROSS FROM
WINDOWS AND DOORS. AVOID ANCHORING THE VENT AND
INTAKE PIPES DIRECTLY TO FRAMED WALLS, FLOORS OR
CEILINGS UNLESS RUBBER ISOLATION PIPE HANGERS ARE
USED. THIS PREVENTS ANY VIBRATIONS FROM BEING
TRANSMITTED INTO THE LIVING SPACES.
The vent system must terminate so that proper clearances are
maintained as cited in local codes or the latest edition of the National
Fuel Gas Code, ANSI Z223.1/NFPA 54 and for Canadian
installations consult the Canadian Installation Codes and
CAN/CGA B149.1 and .2.
1. Do not terminate the exhaust vent terminal over public area where
condensate or vapor can cause nuisance or hazard.
2. For direct vent, the venting system shall terminate at least
1' (30.5 cm) below, 1' (30.5 cm) horizontally from or 1' (30.5
cm) above any door, window, or gravity air inlet into building.
3. For the horizontal venting system, using room air for combustion,
per
the vent terminal shall terminate 4' (122 cm) below, 4' (122 cm)
horizontally from or 1' (30.5 cm) above any door, window, or
gravity air inlet into building.
6
WARNING

VENTING

WARNING
WARNING
CAUTION
IMPORTANT