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.
e. 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.
3.Working from furnace to outside, cut pipe to required length(s).
4.Deburr inside and outside of pipe.
5.Chamfer outside edge of pipe for better distribution of primer and cement.
6.Clean and dry all surfaces to be joined.
7.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.
8.After pipes have been cut and preassembled, apply gener- ous 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.
9.While cement is still wet, twist pipe into socket with 1/4 turn. Be sure pipe is fully inserted into fitting socket.
10.Wipe excess cement from joint. A continuous bead of cement will be visible around perimeter of a properly made joint.
11.Handle pipe joints carefully until cement sets.
12.Support combustion-air and vent piping a minimum of every 5 ft (3 ft for SDR-21 or -26 PVC) using perforated metal hanging strap.
13.Slope combustion-air and vent pipes downward toward furnace a minimum of 1/4 in. per linear ft with no sags between hangers.
14.Use appropriate methods to seal openings where vent and combustion-air pipes pass through roof or side wall.
III.CONCENTRIC VENT AND COMBUSTION-AIR TERMINATION KIT INSTALLATION
NOTE: If these instructions differ from those packaged with termination kit, follow kit instructions.
Combustion-air and vent pipes must terminate outside structure. A factory accessory termination kit must be installed in 1 of the installations shown in Fig. 36, 37, 38, 39, and 40. Four termination kits are available.
1.The 2-in. termination bracket kit is for 1-in., 1-1/2 in., and 2-in. diameter 2-pipe termination systems.
2.The 3-in. termination bracket kit is for 2-1/2 in., 3-in., and 4-in. diameter 2-pipe termination systems.
3.The 2-in. concentric vent/air termination kit is for 1-in., 1-1/2 in., 2-in., and 2-1/2 in. diameter pipe systems when single penetration of wall or roof is desired.
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4.The 3-in. concentric vent/air termination kit is for 2-1/2 in., 3-in., and 4-in. diameter pipe systems when single penetra- tion of wall or roof is desired.
NOTE: Shaded parts in Fig. 36, 37, 38, 39, and 40 are considered to be termination. These components should NOT be counted when determining pipe diameter. Roof termination is preferred since it is less susceptible to damage, has reduced chances to take in contaminants, and has less visible vent vapors. (See Fig. 36 or 37.) Sidewall termination may require sealing or shielding of building surfaces with a corrosive resistance material due to corrosive combustion products of vent system.
A. Extended Exposed Sidewall Pipes
Sidewall combustion-air and vent pipe terminations may be extended beyond area shown in Fig. 39 or 40 in outside ambient by insulating pipes as indicated in Table 8.
1.Determine combustion-air and vent pipe diameters, as stated above, using total pipe length and number of elbows.
2.Using winter design temperature (used in load calculations), find appropriate temperature for your application and fur- nace model.
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 7.
B.Two-Pipe Termination Kit
1.Determine location for termination.
Consideration of the following should be made when determining an appropriate location for termination kit.
a.Comply with all clearance requirements as stated in Table 5.
b.Termination kit should be positioned where vent vapors will not damage plants/shrubs or air conditioning equip- ment.
c.Termination kit should be positioned so that it will not be affected by wind eddy (such as inside building corners) or allow recirculation of flue gases, airborne leaves, or light snow.
d.Termination kit should be positioned where it will not be damaged by or subjected to foreign objects, such as stones, balls, etc.
e.Termination kit should be positioned where vent vapors are not objectionable.
2.Cut 2 holes, 1 for each pipe, of appropriate size for pipe size being used.
3.Loosely install elbow in bracket and place assembly on combustion-air pipe.
Roof terminations—Loosely install pipe coupling on prop- erly cut vent pipe. Coupling must be positioned so bracket will mount as shown in Fig. 36.
For applications using combustion-air pipe option, indi- cated by dashed lines in Fig. 36, install 90° street elbow into 90° elbow, making U-fitting. A 180° U-fitting may be used.
Sidewall terminations—Install bracket as shown in Fig. 39 or 40.
For applications using vent pipe option indicated by dashed lines in Fig. 39, rotate vent elbow 90° from position shown in Fig. 39.
4.Disassemble loose pipe fittings. Clean and cement using same procedures as used for system piping.