Page 545 - 2018_IRC

CHIMNEYS AND VENTS

natural draft venting system shall comply with the following corrosion and heat and thickness not less than that of galva-
requirements: nized steel as specified in Table M1803.2.
1. Appliances that are connected to common venting sys- TABLE M1803.2
tems shall be located on the same floor of the dwelling. THICKNESS FOR SINGLE-WALL METAL PIPE CONNECTORS
GALVANIZED SHEET
Exception: Engineered systems as provided for in DIAMETER OF METAL GAGE MINIMUM THICKNESS
Section G2427. CONNECTOR (inches) NUMBER (inch)
2. Inlets to common venting systems shall be offset such Less than 6 26 0.019
that no portion of an inlet is opposite another inlet. 6 to 10 24 0.024
3. Connectors serving appliances operating under a natu- Over 10 through 16 22 0.029
ral draft shall not be connected to any portion of a For SI: 1 inch = 25.4 mm.
mechanical draft system operating under positive pres- M1803.3 Installation. Vent and chimney connectors shall be
sure. installed in accordance with the manufacturer’s instructions
M1801.12 Multiple solid fuel prohibited. A solid fuel-burn- and within the space where the appliance is located. Appli-
ing appliance or fireplace shall not connect to a chimney pas- ances shall be located as close as practical to the vent or
sageway venting another appliance. chimney. Connectors shall be as short and straight as possible
1
and installed with a slope of not less than / inch (6 mm) rise
4
per foot of run. Connectors shall be securely supported and
SECTION M1802 joints shall be fastened with sheet metal screws or rivets.
VENT COMPONENTS Devices that obstruct the flow of flue gases shall not be
M1802.1 Draft hoods. Draft hoods shall be located in the installed in a connector unless listed and labeled or approved
same room or space as the combustion air openings for the for such installation.
appliances. M1803.3.1 Floor, ceiling and wall penetrations. A chim-
M1802.2 Vent dampers. Vent dampers shall comply with ney connector or vent connector shall not pass through any
Sections M1802.2.1 and M1802.2.2. floor or ceiling. A chimney connector or vent connector
M1802.2.1 Manually operated. Manually operated shall not pass through a wall or partition unless the con-
dampers shall not be installed except in connectors or nector is listed and labeled for wall pass-through, or is
chimneys serving solid fuel-burning appliances. routed through a device listed and labeled for wall pass-
through and is installed in accordance with the conditions
M1802.2.2 Automatically operated. Automatically oper- of its listing and label. Connectors for oil-fired appliances
ated dampers shall conform to UL 17 and be installed in listed and labeled for Type L vents, passing through walls
accordance with the terms of their listing and label. The or partitions shall be in accordance with the following:
installation shall prevent firing of the burner when the
damper is not opened to a safe position. 1. Type L vent material for oil appliances shall be
installed with not less than listed and labeled clear-
M1802.3 Draft regulators. Draft regulators shall be pro- ances to combustible material.
vided for oil-fired appliances that must be connected to a
chimney. Draft regulators provided for solid fuel-burning 2. Single-wall metal pipe shall be guarded by a venti-
appliances to reduce draft intensity shall be installed and set lated metal thimble not less than 4 inches (102 mm)
in accordance with the manufacturer’s installation instruc- larger in diameter than the vent connector. Not less
tions. than 6 inches (152 mm) of clearance shall be main-
tained between the thimble and combustibles.
M1802.3.1 Location. Where required, draft regulators
shall be installed in the same room or enclosure as the M1803.3.2 Length. The horizontal run of an uninsulated
appliance so that a difference in pressure will not exist connector to a natural draft chimney shall not exceed 75
between the air at the regulator and the combustion air percent of the height of the vertical portion of the chimney
supply. above the connector. The horizontal run of a listed connec-
tor to a natural draft chimney shall not exceed 100 percent
of the height of the vertical portion of the chimney above
SECTION M1803 the connector.
CHIMNEY AND VENT CONNECTORS M1803.3.3 Size. A connector shall not be smaller than the
M1803.1 General. Connectors shall be used to connect fuel- flue collar of the appliance.
burning appliances to a vertical chimney or vent except Exception: Where installed in accordance with the
where the chimney or vent is attached directly to the appli- appliance manufacturer’s instructions.
ance. M1803.3.4 Clearance. Connectors shall be installed with
M1803.2 Connectors for oil and solid fuel-burning appli- clearance to combustibles as set forth in Table M1803.3.4.
ances. Connectors for oil and solid fuel-burning appliances Reduced clearances to combustible materials shall be in
shall be constructed of factory-built chimney material, Type accordance with Table M1306.2 and Figure M1306.1.
L vent material or single-wall metal pipe having resistance to

520 2018 INTERNATIONAL RESIDENTIAL CODE ®
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