269326-UIM-A-1106
16 Unitary Products Group
SECTION VII: VENT/COMBUSTION AIR
SYSTEM
VENT SAFETY
This Category I, furnace is designed for residential application. It may
be installed without modification in a basement, garage, equipment
room, alcove, attic or any other indoor location where all required clear-
ance to combustibles and other restrictions are met.
CATEGORY 1 - 450 F. MAX. VENT TEMP.
The venting system must be installed in accordance with Section 5.3,
Air for Combustion and Ventilation, of the National Fuel Gas Code
Z223.1/NFPA 54 (latest edition), or Sections 7.2, 7.3 or 7.4 of CSA
B149.1, National Gas and Propane Codes (latest edition) or applicable
provisions of the local building code and these instructions.
The furnace shall be connected to any type of B, BW or L vent connec-
tor, and shall be connected to a factory-built or masonry chimney. The
furnace shall not be connected to a chimney flue serving a sepa-
rate appliance designed to burn solid fuel.
The furnace rating plate lists the maximum vent gas temperature. This
temperature must be used to select the appropriate venting materials
and clearances.
It is recommended that the appliance is installed in a location where the
space temperature is 32 °F (0°C) or higher. If the appliance is installed
in a location where the ambient temperature is below 32 °F (0°C), the
flue by-products could condense causing damage to the appliance heat
exchanger.
IMPORTANT: The “VENT SYSTEM” must be installed as specified in
these instructions for Residential and Non HUD Modular Homes.
This appliance may be common vented with another gas appliance for
residential installations as allowed by the codes and standards listed in
these instructions.
Non-HUD approved Modular Homes must be vented with a listed dou-
ble wall or B-vent system and may not be common vented with other
appliances.
VENTING
Category I venting consists of vertically venting one or more appliances
in B-vent or masonry chimney (as allowed), using single wall metal pipe
or B-vent connectors. Type B-vent system extends in a general vertical
direction and does not contain offsets exceeding 45 degrees. A vent
system having not more than one 60 degree offset is permitted.
FIGURE 24: Vent Termination
FIGURE 25: Vent Termination
TABLE 8:
Roof Pitch
ROOF PITCH H(min) ft m
Flat to 6/12 1.0 0.30
6/12 to 7/12 1.25 0.38
Over 7/12 to 8/12 1.5 0.46
Over 8/12 to 9/12 2.0 0.61
Over 9/12 to 10/12 2.5 0.76
Over 10/12 to 11/12 3.25 0.99
Over 11/12 to 12/12 4.0 1.22
Over 12/12 to 14/12 5.0 1.52
Over 14/12 to 16/12 6.0 1.83
Over 16/12 to 18/12 7.0 2.13
Over 18/12 to 20/12 7.5 2.27
Over 20/12 to 21/12 8.0 2.44
WALL OR
PARAPET
CHIMNEY
NOTE: NO
HEIGHT ABOVE
PARAPET REQUIRED
WHEN DISTANCE
FROM WALLS OR
PARAPET IS MORE
THAN 10 FT (3.0 m).
3 FT (0.9 m)
MIN.
MORE THAN
10 FT (3.0 M)
2 FT(0.6 m)
MIN
RIDGE
CHIMNEY
HEIGHT ABOVE ANY
ROOF SURFACE WITHIN
10 FT (3.0 m) HORIZONTALLY
3 FT (0.9 m)
MIN
MORE THAN
10 FT (3.0 M)
LOWEST DISCHARGE OPENING
LISTED CAP
LISTED GAS
VENT
H (min) - MINIMUM HEIGHT FROM ROOF
TO LOWEST DISCHARGE OPENING
12
X
ROOF PITCH
IS X/12
FIGURE 26: Alternate Air Intake, Air Outlet and Chimney Connections
CHIMNEY OR
GAS VENT
VENTILATION LOUVERS
(Each end of attic)
OUTLET
AIR
INLET
AIR
ALTERNATE
AIR INLET
VENTIALTION LOUVERS FOR UNHEATED CRAWL SPACE
FURNACE
WATER
HEATER
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