Carrier 58MCB Installation, Start-Up, And Operating Instructions Manual page 38

COMBUSTION AIR
PIPE (NON-DIRECT
VENT/1-PIPE)
VENT PIPE
HORIZONTAL TO ROOF
COMBUSTION AIR
PIPE (DIRECT VENT
/2-PIPE)
COMBUSTION AIR
PIPE (NON-DIRECT
VENT/1-PIPE)
VERTICAL TO ROOF
Attachment of Vent Extension Pipe
Furnaces with 100,000 Btuh and larger input 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.
Installation Guidelines for Combustion Air Pipe and Vent Pipe
It is recommended that all pipes be cut, prepared, and pre-
assembled before permanently cementing any joint.
1. Attach combustion air pipe and vent pipe per instructions in
sections "Combustion Air Pipe" and "Vent Pipe."
2. Working from furnace to outside, cut pipe to required
length(s).
3. Deburr inside and outside of pipe.
4. Chamfer outside edge of pipe for better distribution of primer
and cement.
5. Clean and dry all surfaces to be joined.
6. Check dry fit of pipe and mark insertion depth on pipe.
7. 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
12 " MIN
12 " MIN
NOTE: A 12-In. minimum offset pipe section is recommended with
short (5-ft. to 8-ft) vent systems. This recommendation is to
reduce excessive condensate droplets from exiting the vent pipe.
→ Fig. 39—Short Vent (5 to 8 ft) System
COMBUSTION AIR
PIPE (DIRECT VENT
/2-PIPE)
COMBUSTION AIR
PIPE (NON-DIRECT
VENT/1-PIPE)
VENT PIPE
HORIZONTAL TO SIDEWALL
VENT PIPE
COMBUSTION AIR
PIPE (NON-DIRECT
VENT/1-PIPE)
VERTICAL TO SIDEWALL
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.
8. While cement is still wet, twist pipe into socket with 1/4 turn.
Be sure pipe is fully inserted into fitting socket.
9. Wipe excess cement from joint. A continuous bead of cement
will be visible around perimeter of a properly made joint.
10. Handle pipe joints carefully until cement sets.
11. Horizontal portions of the venting system shall be supportive
to prevent sagging support. Support combustion air piping (if
applicable) and vent piping a minimum of every 5 ft (3 ft for
SDR-21 or -26 PVC) using perforated metal hanging strap.
12. Slope combustion air piping (if applicable) and vent piping
downward towards furnace a minimum of 1/4 in. per linear ft
with no sags between hangers.
13. Horizontal portions of the venting system shall be installed so
as to prevent the accumulation of condensate.
14. Use appropriate methods to seal openings where combustion
air pipe (if applicable) and vent pipe pass through roof or
sidewall.
38
12 " MIN
COMBUSTION AIR
PIPE (DIRECT
VENT/2-PIPE)
COMBUSTION AIR
PIPE (DIRECT VENT
/2-PIPE)
12 " MIN
VENT PIPE
A05094