6
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, should be provided. Each opening should have a free
area of not less than one square inch (6.5 cm²) per 4000 Btuh of the total
input of all appliances in the enclosure. If horizontal ducts are used, each
opening should have a free area of not less than one square inch (6.5 cm²) per
2000 Btuh of the total input of all appliances in the enclosure.
CHEMICAL VAPOR CORROSION
WARNING
CORROSION OF THE FLUE WAYS AND VENT SYSTEM MAY OCCUR IF
AIR FOR COMBUSTION CONTAINS CERTAIN CHEMICAL VAPORS. SUCH
CORROSION COULD 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.
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 during shutdown periods.
WARNING
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 Figures 5 and 6 before proceeding.
CAUTION
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.
HARD WATER
Where hard water conditions exist, water softening or the threshold type of
water treatment is recommended. This will protect the dishwashers, coffee
urns, water heaters, water piping and other equipment.
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.
WARNING
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 should be provided with two
permanent openings, ONE IN OR WITHIN 12" (31 cm) OF THE ENCLOSURE
TOP AND ONE IN OR WITHIN 12" (31 cm) OF THE ENCLOSURE BOTTOM.
Each opening should have a free area of at least one square inch (6.5 cm²)
per 1000 Btuh appliances in the enclosure, but not less than 100 square
inches (645 cm²).
