Riello RTC Series, Руководство пользователя

Страница: 32 / 52

32
INSTALLAZIONE
2.10.1 Venting Requirements
9
WARNING: Risk of system damage or personal injury!
The vent system could fail, causing flue gas spillage, resulting
in severe personal injury or death.
− Use only an approved vent starter coupling and approved
vent pipe from
R
− Do not mix components from different systems.
9
NOTICE: Risk of system damage!
− Connect an oil-fired unit to a vent having sufficient draft at
all times to ensure safe and proper operation of the unit.
The RTC Boiler is a category II or IV appliance and the exhaust vent
materials must be UL listed for use with a category IV appliance:
operating temperatures of up to 240 °F, positive pressure, conden-
sing flue gas. Currently, UL Listed vents of AL29-4C or 316L stain-
less steel must be used with the RTC Boiler. Proper clearances to
combustibles must be maintained per UL and vent manufacturer
instructions.
The specifying engineer should dictate flue venting as appropriate
to the installation.
The vent system should be designed to facilitate smooth travel
for both the intake and exhaust. Avoid the use of bullhead tees
and back-to-back 90 degree elbows. The exhaust system must
never be installed in a downward fashion. Be sure to follow all
instructions provided by the vent manufacturer.
Keep the supply of combustion air free of corrosive substances
(e.g. halogenated hydrocarbons that contain chlorine or fluorine
compounds). This will help prevent corrosion. Never use or sto-
re chlorinated cleaning agents or halogenated hydrocarbons (as
contained in spray cans, solvents or cleaning agents, paints and
adhesives, for example) in the boiler room.
UL, NFPA 54 & 211, ANSI Z223.1 guidelines are often the basis for
state and local codes. Follow the guidelines of these recognized
agencies unless codes applicable to the installation site are most
stringent. The venting and combustion air systems must meet all
applicable code requirements. Where code differs from the in-
structions provided with the equipment, code will take preceden-
ce.
Constant pressure at the flue gas outlet is not required. Size the
flue system to limit pressure variations. The maximum allowable
breech pressure for design of the flue system is positive 0.2" W.C.
for proper combustion and light off.
A draft control system may be required to ensure proper draft
when two or more boilers are connected to a common stack. Con-
sult the flue material manufacturer for design calculations and
recommendations.
2.10.2 Code Required Vent Terminations
Horizontal Terminations:
− Vent terminations should be at least 4 feet below, 1 foot
above or 4 feet horizontally from any window, door or gra-
vity air inlet of a building.
− The termination shall be at least 6 feet away from any other
building opening, gas utility meter, service regulator or the
like.
− The termination shall be at least 6 feet away from the com-
bustion air intake of any other appliance.
− The bottom of the vent terminal should be at least 12 inches
above both finished grade and any snow accumulation
point.
− Vent should not terminate over public walkways or over an
area where condensate or vapor could create a nuisance or
be detrimental to the operation of regulators, meters and
other equipment.
− Discharges should not be in wind-blocked areas, corners,
or directly behind vegetation.
Vertical Terminations:
− Roof penetrations should follow all appliance codes and
the vent manufacturer‘s instructions. The vent should
never be installed at less than the required clearances to
combustible materials per UL, NFPA and local codes. “Dou-
ble-wall or thimble” assemblies are required when pene-
trating combustible walls and roofs.
− Vertical discharges should extend at least 2 feet above the
roof through properly flashed penetrations and at least 2
feet above anything within a 10 foot horizontal diameter.
Discharges that extend more than 2 feet above the roof
must be laterally supported.
− If the vent systems is to be connected to an existing stack,
the stack must be UL Listed for Category II or IV appliances
(capable of 240 °F, positive pressure and condensing flue
gas operation).
− Masonry stacks must be lined and the vent penetration
must terminate flush with and be sealed to this liner. Vents
may enter the stack through the bottom or side.
− RTC Boiler vent systems must not be interconnected to any
other venting system; The RTC Boiler is designed to main-
tain its own vent system.
− The exhaust vent must be pitched up toward the termina-
tion a minimum of 1/4 inch per foot of length. Condensate
must flow back to the boiler flue collector freely, without
accumulating in the vent.
2.10.3 Combustion Air from outside the building
Two permanent openings method
If outside combustion air is required, the room shall have two per-
manent louvered openings to the outdoors. Each opening must
have a minimum free area of 1 square inch for each 4,000 Btu/hr of
total input rating of all fuel burning equipment in the space. When
the air is supplied to the room via ducts, two ducts must be used.
Vertical ducts and openings must have a minimum free area of
1 square inch for each 4,000 Btu/hr of the total input rating of all
fuel burning equipment in the space. Horizontal ducts and ope-
nings must have a minimum free area of 1 square inch for each
2,000 Btu/hr of the total input rating of all fuel burning equipment
in the space.
One permanent opening method
If outside combustion air is required, the room shall have one
permanent louvered openings to the outdoors. The opening must
communicate directly with the outdoors or through a duct in ei-
ther a vertical or horizontal arrangement. The opening must have
a minimum free area of 1 square inch for each 3,000 Btu/hr of total
input rating of all fuel burning equipment in the space.
The free area of the openings must be taken into account re-
strictions from the louvers and screens. The louver manufactu-
rer should be consulted for the percentage of free area available.
When free area is not known, metal louvers typically have 60-70%
of free area, wooden louvers have between 20-25% of free area.
Louvers should be in a fixed position or interlocked with equi-
pment so that they open automatically during equipment ope-
ration. The combustion air damper opening shall be located as
follows: top louver shall began within 12” of the ceiling and the
bottom louver within 12” of the floor as prescribed in NFPA 54.
Direct intake method
If outside combustion air is required, air may be drawn from the
outdoors via a duct connected directly to the burner intake. The
duct shall be constructed of galvanized steel or a material having
equivalent strength and rigidity. Refer to the burner manufactu-
rer's recommendations and installation instructions for additional
guidelines and application requirements.