Buderus Logano plus SB615 Installation And Servicing Instructions page 21

SB boiler combustion air supply requirements
The SB boiler is a Category II or IV appliance and the flue
system components must be approved for use with UL
Category IV appliances: operating temperatures up to
239°F (115 °C), positive pressure, condensation-resistant.
At present, UL-listed flue systems made of AL29-4C or
316L stainless steel must be used with SB boilers. Use
only fuels permitted under UL approval. Consult vent sys-
tem manufacturer for further information.
UL, NFPA 211 and NFPA 54 (National Flue Gas Code
ANSI Z223.1) guidelines are often the basis for national
and local regulations. You must follow the guidelines in this
manual unless local rules and regulations are stricter. In
that case follow those. The flue and air supply systems
must comply with all applicable requirements.
Code requirements for flue systems
Horizontal flues
The flue terminal should be at least 48" (1200 mm) be-
low, 12" (300 mm) above or 48" (1200 mm) to the side
of any window, door or ventilation device.
The flue terminal should be at least 36" (1000 mm)
from any other openings, gas meters, servicing equip-
ment or the like.
The flue terminal must be at least 12" (300 mm) above
the high snow mark.
Flue outlets must not be installed over public footways
or areas where condensation or steam would be a nui-
sance or where they would affect the operation of con-
trols, gas meters or other equipment.
Flue gas should not be discharged directly into areas
sheltered from the wind, corners or directly behind
trees or bushes.
Logano plus SB615 - Technical specifications are subject to change without prior notice.
Vertical flues
Roof penetrations should follow all applicable codes
and the vent manufacturer's instructions. The vent
should never be installed at less than the required clear-
ances to combustible materials per UL, NFPA, and lo-
cal codes. "Double-wall or thimble" assemblies are
required when penetrating combustible walls and
roofs.
Vertical discharges should extend at least 2 feet
(60 cm) above the roof through properly flashed
penetrations and at least 2 feet (60 cm) above anything
within a 10 foot (3 m) horizontal diameter.
Discharges that extend more than 2 feet (60 cm) above
the roof must be laterally supported.
If the vent system 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.
SB Boilers vent systems must not be interconnected to
any other venting system; The SB Boiler is
designed to maintain its own vent system.
The flue pipe must slope upwards towards the end pipe
at least ¼" (6 mm) per foot (30 cm). The condensate
must be able to run back to the SB boiler without ob-
struction and without collecting in the flue pipe.
Installation 7
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