General Venting Instructions; Venting Materials - American Standard CUX1B040A9241A Installation, Operation And Maintenance Manual

THIS FURNACE MUST BE VENTED TO THE OUTDOORS.
THESE FURNACES ARE INDUCED DRAFT VENTED AND
MUST NOT BE CONNECTED TO ANY VENT SERVING AN-
OTHER APPLIANCE. PLEASE NOTE THAT THESE FUR-
NACES USE POSITIVE-PRESSURE VENT SYSTEMS.
Proper venting is essential to obtain maximum efficiency from a
condensing furnace. Proper installation of the vent system is
necessary to assure drainage of the condensate and prevent
deterioration of the vent system.
American Gas Association has certified the design of condensing
furnaces for a minimum of 0" clearance from combustible mate-
rials with a single wall plastic vent pipe.
The recommended system is assembled from 2", 2-1/2", or 3" plas-
tic pipe and fittings (See Table 7, page 14). Where the system is
routed to the outdoors through an existing masonry chimney
containing flue products from another gas appliance, or where
required by local codes, then 3" venting of Type 29-4C stainless
steel must be used in place of PVC material.
These furnaces have been classified as CATEGORY IV furnaces
in accordance with the latest edition of ANSI Z21.47 • CAN/CGA-
2.3 Standards. Category IV furnaces operate with positive vent
pressure and with a vent gas temperature less than 140° F above
the dewpoint. These conditions require special venting systems,
which must be gas tight and water tight.
NOTE:
When an existing furnace is removed from a venting system
serving other gas appliances, the venting system is likely to be
too large to properly vent the remaining
attached appliances.
The following steps shall be followed with each appliance remain-
ing connected to the common venting system placed in operation,
while the other appliances remaining connected to the common
venting system are not in operation.
1. Seal any unused openings in the common venting system.
2. Visually inspect the venting system for proper size and
horizontal pitch and determine there is no blockage or restriction,
leakage, corrosion or other deficiencies which could cause an
unsafe condition.
IMPORTANT:
These furnaces may be installed as Direct Vent (sealed combus-
tion) or as Nondirect vent (single pipe). The furnaces are shipped
DIRECT VENT with sealed combustion.
For DIRECT VENT APPLICATION: The furnaces must be vented to
the exterior of the house and combustion air MUST come through
the inlet air pipe FROM OUTSIDE AIR.
For NONDIRECT VENT APPLICATION: The furnace shall be
vented to the exterior of the house, but combustion air may enter
from the surrounding area as long as combustion air requirements
are met. (See AIR FOR COMBUSTION AND VENTILATION)
IMPORTANT:
Products installed in Canada must use vent systems that are certi-
fied to the Standard for Type BH Gas Venting Systems (ULC S636)
for Class II-A venting systems (up to 65°C). Components of the
vent system must not be interchanged with other vent systems or
unlisted pipe or fittings. Plastic components, specified primers,
and glues must be from a single system manufacturer and not in-
termixed with other system manufacturer's vent system parts. In
addition, the first three feet of the vent pipe must be visible for in-
spection.
Pub. No. 41-5016-12

VENTING MATERIALS

GENERAL VENTING
3. Insofar as is practical, close all building doors and windows
and all doors between the space in which the appliances remaining
connected to the common venting system are located and other
spaces of the building. Turn on clothes dryers and any appliances
not connected to the common venting system. Turn on any exhaust
fans, such as range hoods and bathroom exhausts, so they will
operate at maximum speed. Do not operate a summer exhaust fan,
close fireplace dampers.
4. Follow the lighting instructions. Place the appliance being
inspected in operation. Adjust thermostat so appliance will oper-
ate continuously.
5. Test for spillage at the draft hood relief opening after 5 min-
utes of main burner operation. Use the flame of a match or candle,
or smoke from a cigarette, cigar, or pipe.
6. After it has been determined that each appliance remaining
connected to the common venting system properly vents when
tested as outlined above, return door, windows, exhaust fans,
fireplace dampers and any other gas-burning appliance to their
previous conditions of use.
If improper venting is observed during any of the above tests, the
remaining common venting system must be corrected. Correction
of the remaining common vent system should be done by referring
to the latest edition of the National Fuel Gas Code (ANSI
Z223.1) • CAN/CGA B149.1 Installation Codes or "Exhibit J" of
ANSI Z21.47 • CAN/CGA-2.3 Standards. The following are gen-
eral steps to be used to correct or resize a remaining vent system
when a furnace which may not be common vented is removed from
the system:
a. Determine the Btu per hour input of all remaining appli-
ances attached to the venting system.
b. Determine the diameter, rise, and lateral of the existing
venting system, as well as quantity and type of bends.
c. Use the appropriate tables in the latest edition of
the National Fuel Gas Code (ANSI Z223.1 •
CAN/CGA B149.1 Installation Codes or "Exhibit J" of
ANSI Z21.47 • CAN/CGA-2.3 Standards. "Exhibit J" in-
cludes examples and drawings of typical venting systems.
PVC VENT FITTING MATERIAL
These fittings are available from your Gas Furnace Distributors.
Straight Pipe Sections, Couplings, 45° Elbows, 60° Elbows, 90°
Elbows, Vent or Sanitary Tee, or other necessary fittings may be
2", 2½", 3", or 4" diameter. The allowable materials are shown in
Table 7. A vent screen is optional, but recommended. The vent
screen must be 3/8" open mesh weave (minimum 70% open), made
of any non-corrosive material having at least 3/8" open mesh
weave.
VENT FITTING MATERIAL – PLASTIC
Gas and liquid tight single wall vent fittings, designed for resis-
tance to corrosive flue condensate, MUST be used throughout.
Listed in Table 8 & 9 are 2", 2½", 3", and 4" size fittings that meet
these requirements. The materials listed are various grades of
PVC and ABS plastic.
PIPE JOINTS: All joints must be fastened and sealed to prevent
escape of combustion products into the building.
Installation Instructions
Page 11