Bryant 345MAV User Manual

Page 22

REMOVAL OF EXISTING FURNACES FROM

COMMON VENT SYSTEMS

If furnace being replaced was connected to a common vent system
with other appliances, the following steps shall be followed with
each appliance connected to the venting system placed in opera-
tion, while any other appliances connected to the venting system
are not in operation:

1. Seal any unused openings in the venting system.

2. Inspect the venting system for proper size and horizontal

pitch as required in the National Fuel Gas Code, ANSI
Z223.1 or the CAN/CGA B149 Installation Codes and these
instructions. Determine that there is no blockage or restric-
tion, leakage, corrosion, and other deficiencies which could
cause an unsafe condition.

3. In so far as is practical, close all building doors and

windows and all doors between the space in which the
appliance(s) connected to the venting system are located
and other spaces of the building. Turn on clothes dryers and
any appliance not connected to the venting system. Turn on
any exhaust fans, such as range hoods and bathroom
exhausts, so they shall 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 shall
operate continuously.

5. Test for draft hood equipped appliance spillage at the draft

hood relief opening after 5 minutes of main burner opera-
tion. Use the flame of a match or candle.

6. After it has been determined that each appliance connected

to the venting system properly vents when tested as outlined
above, return doors, windows, exhaust fans, fireplace damp-
ers, and any other gas-burning appliance to their previous
conditions of use.

7. If improper venting is observed during any of above tests,

the venting system must be corrected.

Vent system or vent connectors may need to be resized. For any
other appliances when resizing vent systems or vent connectors,
system or connector must be sized to approach minimum size
determined in appropriate table in NFGC or NSCNGPIC.

II.

COMBUSTION-AIR AND VENT PIPING

General

WARNING:

Solvent cements are combustible. Keep

away from heat, sparks, and open flame. Use only in
well-ventilated areas. Avoid breathing in vapor or allow-
ing contact with skin or eyes. Failure to follow this
warning could result in fire, property damage, personal
injury, or death.

Combustion-air and vent pipe fittings must conform to American
National Standards Institute (ANSI) standards and American
Society for Testing and Materials (ASTM) standards D1785
(schedule-40 PVC), D2665 (PVC-DWV), D2241 (SDR-21 and
SDR-26 PVC), D2661 (ABS-DWV), F628 (schedule-40 ABS), or
F891 (PVC-DWV cellular core). Pipe cement and primer must
conform to ASTM standards D2564 (PVC) or D2235 (ABS).

In Canada construct all combustion-air and vent pipes for this unit
of CSA or ULC certified schedule-40 PVC, PVC-DWV or
ABS-DWV pipe and pipe cement. SDR pipe is NOT approved in
Canada.

Combustion Air Pipe

CAUTION:

Combustion air must not be taken from

inside a structure that is frequently contaminated by
halogens, which include fluorides, chlorides, bromides,
and iodides. These elements are found in aerosols,
detergents, bleaches, cleaning solvents, salts, air freshen-
ers, adhesives, paint, and other household products.
Locate combustion-air inlet as far as possible from
swimming pool and swimming pool pump house.
Excessive exposure to contaminated combustion air will
result in safety and performance related problems.

NOTE:

Furnace combustion-air connections are sized for 2-in.

pipe. The combustion-air pipe will be 2-in. diameter in all
installations.

Furnace combustion-air connection must be attached as shown in
Fig. 28. Combustion-air intake housing plug may need to be
relocated in some applications.

Combustion-air pipe must terminate outside of furnace casing with
1 elbow. Orient elbow so that opening faces down for upflow or
downflow applications. Orient elbow so that it faces sideways (left
or right) for horizontal left or horizontal right applications. (See
Fig. 28.) Maintain a 3-in. minimum clearance between the opening
of the combustion-air inlet pipe and any object.

NOTE:

All pipe joints must be watertight except attachment of

combustion-air inlet pipe to inlet housing connection, since it may
be necessary to remove pipe for servicing.

Install combustion air inlet pipe as follows:

Fig. 28—Combustion-Air and Vent Pipe Connections

CAUTION:

Make sure there is adequate clearance (3-in.

minimum) to any fixed or loose objects in order to ensure
an adequate combustion-air supply.

A96188

COMBUSTION-
AIR

COMBUSTION-

AIR

FLOW

VENT

AIR

FLOW

AIR

FLOW

AIR

FLOW

UPFLOW

DOWNFLOW

HORIZONTAL-LEFT DISCHARGE

HORIZONTAL-RIGHT DISCHARGE

Select 1 vent pipe connection and
1 combustion-air pipe connection.

COMBUSTION-

AIR

COMBUSTION-

AIR

COMBUSTION-

AIR

COMBUSTION-

AIR

NOTE:

Select 1 vent pipe connection and
1 combustion-air pipe connection.

NOTE:

VENT

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