Allied Air Enterprises 92G1DF, A95DF, A93DF, 95G1DF Exhaust Pipe Termination Size Reduction, Model

Details of Intake and Exhaust Piping Terminations for Direct Vent Installations

NOTE: In Direct Vent installations, combustion air is taken from outdoors and flue gases are discharged to outdoors.

NOTE: Flue gas may be slightly acidic and may adversely affect some building materials. If any vent termination is used and the flue gases may impinge on the building material, a corrosion-resistant shield (minimum 24 inches square) must be used to protect the wall surface. If the optional tee is used, the protective shield is required. The shield should be constructed using wood, plastic, sheet metal or other suitable material. All seams, joints, cracks, etc. in the affected area should be sealed using an appropriate sealant. See Figure 27.

Intake and exhaust pipes may be routed either horizontally through an outside wall or vertically through the roof. In attic or closet installations, vertical termination through the roof is preferred. Figures 25 through 33 show typical terminations.

1. Exhaust and intake exits must be in same pressure zone.

Do not exit one through the roof and one on the side.

Also, do not exit the intake on one side and the exhaust

DIRECT VENT ROOF TERMINATION KIT

	(15F75 or 44J41)
Inches(mm)	3"(76mm) MAX.	SIZE TERMINATION
		PIPE PER TABLE 8.
		UNCONDITIONED
8" (203mm) MIN		ATTIC SPACE
		1/2" (13mm) FOAM
12" (305mm) ABOVE		INSULATION IN
AVERAGE SNOW		UNCONDITIONED
ACCUMULATION		SPACE (IF REQUIRED)

3" (76mm) OR

2" (51mm) PVC

PROVIDE SUPPORT

FOR INTAKE AND

EXHAUST LINES

FIGURE 25

FLUSH−MOUNT SIDE WALL TERMINATION

51W11

2" EXTENSION FOR 2" PVC PIPE 1" EXTENSION FOR 3" PVC PIPE

	on another side of the house or structure.
2.	Intake and exhaust pipes should be placed as close
	together as possible at termination end (refer to
	illustrations). Maximum separation is 3" (76 mm) on
	roof terminations and 6" (152 mm) on side wall
	terminations.
3.	On roof terminations, the intake piping should terminate
	straight down using two 90° elbows (See Figure 25).

FURNACE INTAKE PIPE

FURNACE

4’’ EXHAUST PIPE

GLUE EXHAUST

END FLUSH INTO

TERMINATION

4. Exhaust piping must terminate straight out or up as

shown. A reducer may be required on the exhaust piping

at the point where it exits the structure to improve the

velocity of exhaust away from the intake piping. See

Table 8.

EXHAUST PIPE TERMINATION SIZE REDUCTION

MODEL	Exhaust Pipe Size	Termination
		Pipe Size
*045 and *070	2" (51mm), 2−1/2" (64mm),	1−1/2" (38mm)
	3" (76mm)
*090		2" (51mm)
110	3" (76mm)	2" (51mm)

TABLE 8

*045, 070 and 090 units with the flush−mount termination must use the 1−1/2"accelerator supplied with the kit.

5.On field supplied terminations for side wall exit, exhaust piping may extend a maximum of 12 inches (305 mm) for 2" PVC and 20 inches (508 mm) for 3" (76 mm) PVC beyond the outside wall. Intake piping should be as short as possible. See Figures 28 and 29.

NOTE: Care must be taken to avoid recirculation of exhaust back into intake pipe.

FLAT SIDE

1−1/2" ACCELERATOR

(all −45, −070 and −090 units)

FIGURE 26

6.On field supplied terminations, a minimum distance between the end of the exhaust pipe and the end of the intake pipe without a termination elbow is 8" and a minimum distance of 6" with a termination elbow. See Figures 28 and 29.

7.If intake and exhaust piping must be run up a side wall to position above snow accumulation or other obstructions, piping must be supported every 24" (610 mm) as shown in Figures 28 and 29.

When exhaust and intake piping must be run up an outside wall, the exhaust piping must be terminated with pipe sized per Table 8. The intake piping may be equipped with a 90° elbow turndown. Using turndown will add 5 feet (1.5 m) to the equivalent length of the pipe.

8.Based on the recommendation of the manufacturer, a multiple furnace installation may use a group of up to four terminations assembled together horizontally, as shown in Figure 32.

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