Vent Termination; Multiventing - Carrier 58MSA Installation, Start-Up, And Operating Instructions Manual

EXAMPLE:
An 080-12 size furnace located in Indianapolis, elevation
650 ft above sea level, could be installed in an application
requiring 3 elbows and 32 ft of vent pipe. Table 8 indicates
this application would allow a 2-in. diameter vent pipe. At
0-2000 ft elevation, 2-in. pipe is good for up to 35 ft with
3 elbows. If same installation were in Albuquerque, eleva-
tion 5250 ft above sea level, installation would require 2-1/2
in. vent pipe. At 5001- to 6000-ft elevation, 2-in. pipe is
allowed for up to 23 ft with 3 elbows, but 2-1/2 in. pipe can
be used for up to 70 ft with 3 elbows.
Install vent pipe as follows:
1. Determine location of vent pipe connection to inducer housing
as shown in Fig. 34 for application.
2. Reposition elastomeric (rubber) inducer housing outlet cap
and clamp to appropriate unused inducer housing connection.
Tighten clamp.
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UNIT DAMAGE HAZARD
Failure to follow this caution could result in unit component
damage.
Inducer housing outlet cap must be installed and fully seated
against inducer housing. Clamp must be tightened to prevent
any condensate leakage.
3. Install pipe support (factory-supplied in loose parts bag) into
selected furnace casing vent pipe hole. Pipe support should be
positioned at bottom of casing hole.
→
UNIT DAMAGE HAZARD
Failure to follow this caution could result in unit component
damage.
Vent pipe must be installed and fully seated against inducer
housing internal stop. Clamp must be tightened to prevent any
condensate leakage.
NOTE: A 2-in. diameter pipe must be used within the furnace
casing. Make all pipe diameter transitions outside furnace casing.
4. Be certain that mating surfaces of inducer housing connection
elastomeric coupling, and 2-in. diameter vent pipe are clean
and dry. Assemble the elastomeric (rubber) vent coupling
(with 2 loose clamps) onto inducer housing connection. Insert
the 2-in. diameter vent pipe through the elastomeric (rubber)
coupling and fully into inducer housing connection until it
bottoms on the internal stop. Tighten both clamps to secure the
pipe to inducer housing. Tighten the clamp screws to 15 in.-lb.
of torque.
5. Install casing hole filler cap (factory-supplied in loose parts
bag) in unused vent pipe casing hole.
VENT EXTENSION PIPE
Some furnaces are supplied with a PVC vent extension pipe
(2-in. diameter by 12-in. long). This pipe has a built-in
channel to assist vent condensate disposal. When this vent
extension pipe is supplied, it must be used to connect the field
vent pipe to furnace inducer housing on ALL upflow and
downflow applications.
NOTE: See label on vent extension pipe for proper installation.
This pipe may be shortened if an elbow is used to connect vent
extension tube to field-installed vent pipe.
6. Working from furnace to outside, cut pipe to required
length(s).
7. Deburr inside and outside of pipe.
8. Chamfer outside edge of pipe for better distribution of primer
and cement.
9. Clean and dry all surfaces to be joined.
10. Check dry fit of pipe and mark insertion depth on pipe.
NOTE: It is recommended that all pipes be cut, prepared, and
preassembled before permanently cementing any joint.
11. After pipes have been cut and preassembled, apply generous
layer of cement primer to pipe fitting socket and end of pipe
to insertion mark. Quickly apply approved cement to end of
pipe and fitting socket (over primer). Apply cement in a light,
uniform coat on inside of socket to prevent buildup of excess
cement. Apply second coat.
12. While cement is still wet, twist pipe into socket with 1/4 turn.
Be sure pipe is fully inserted into fitting socket.
13. Wipe excess cement from joint. A continuous bead of cement
will be visible around perimeter of a properly made joint.
14. Handle pipe joints carefully until cement sets.
15. Support vent piping a minimum of every 5 ft (3 ft for SDR-21
or -26 PVC) using perforated metal hanging strap.
16. Slope vent pipe downward toward furnace a minimum of 1/4
in. per linear ft with no sags between hangers.
17. Use appropriate methods to seal openings where vent pipe
passes through roof or sidewall.
Extended Exposed Sidewall Pipes
Sidewall vent pipe termination may be extended beyond area
shown in Fig. 40 in outside ambient by insulating pipe as indicated
in Table 9.
1. Determine vent pipe diameter, as stated above, using total pipe
length and number of elbows.
2. Find appropriate temperature for your application and furnace
model using winter design temperature (used in load calcula-
tions).
3. Determine required insulation thickness for exposed pipe
lengths.
NOTE: Pipe length (ft) specified for maximum pipe lengths
located in unconditioned spaces cannot exceed total allowable pipe
length as specified in Table 8.

VENT TERMINATION

Vent pipe must terminate either through roof or sidewall. See
Table 10 for required clearances. See Fig. 39, 40, and 41 for
exterior piping arrangements.
Consideration of the following should be made when determining
an appropriate location for termination:
1. Comply with all clearance requirements stated in Table 10.
2. Termination should be positioned where vent vapors will not
damage plants/shrubs or air conditioning equipment.
3. Termination should be positioned where it will not be dam-
aged by or subjected to foreign objects such as stones, balls,
etc.
4. Termination should be positioned where vent vapors are not
objectionable.

MULTIVENTING

When 2 or more 58MSA Furnaces are vented near each other, each
furnace must be individually vented. NEVER common vent or
breach vent 58MSA furnaces.
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