Lennox International Inc TUA45S C-HorizontalVenting - General, D-Horizontal Venting-Commercial

VENT AND AIR INTAKE TERMINATION ON SINGLE WALL VENT

SINGLE WALL TERMINATION

ROOF FLASHING

DOUBLE WALL (TYPE B-1) TERMINATION

ROOF FLASHING

ROOF PITCHED

FROM 0" TO 45"

SHALL NOT BE A CONCEALED SPACE

2" CLEARANCE

THIMBLE

ROOF PITCHED
FROM 0" TO 45"
12" MAX	CLEARANCE TO BE
	AS SPECIFIED ON
	TYPE “B" VENT PIPE.

SEAL JOINT BETWEEN SINGLE WALL VENT AND “B" VENT AND THE ANNULAR SPACE OF THE “B" VENT.

FIGURE 2

C-Horizontal Venting - General

Common venting is not allowed with horizontal vent.

The minimum horizontal vent length is three feet (914mm). 1- If possible, do not terminate the horizontal vent through a wall that is exposed to prevailing wind. Exposure to excessive winds can affect unit performance. If such a termination is necessary, use a wind block to protect the vent termination from direct

winds.

2- Vent termination must be free from obstructions and at least 12" (306mm) above grade level and maximum snow height.

3- Do not terminate vent directly below roof eaves or above a walkway, or any other area where condensate dripping may be troublesome and may cause some staining. Avoid windows where steam may cause fogging or ice buildup.

4- When horizontally vented, minimum clearance for termination from any door, window, gravity air inlet, gas or electric meter, regulators, and relief equipment is 4 ft. (1.2m) for U.S. installations. Refer to NFPA 54/ANSI Z223.1 in the U.S.A. and CSA B149.1 and .2 in Canada or with authorities having local jurisdiction. In Canada, vent termination must have a minimum 6 ft. (1.8mm) horizontal clearance from gas and electric meters and relief devices as specified in the Canadian B149.1, Natural Gas Installation Code.

5- Vent termination must be a minimum of 4' (1.2m) below or 4’ (1.2m) horizontally from any soffit vent or under-eave vent.

6- Vent must be a minimum of 6' from an inside corner formed by two exterior walls. If possible, leave a 10' clearance.

7- Vent termination must be a minimum of 10' (3m) from any forced air inlet (includes fresh air inlet for other appliances, such as a dryer).

8- When termination is routed through an exterior combustible wall the vent must be supported using a listed clearance thimble. Where local authorities permit, a single section of type B-1 vent pipe may be

used as an alternative to the thimble. When using a type B-1 vent termination use the clearances specified by the vent manufacturer. Seal the connection between the single wall and double wall pipes and the annular space of the double wall pipe as shown in figure 2. Inside edge of vent termination tee or Belmont cap must be at least 12 inches from outside wall as shown in figure 3.

9- All horizontal vents must terminate with a tee or with a cap as specified in table 4. Opening end of tee used for termination must face downward. Addition of ¼” (6mm) mesh corrosion resistant material as a bird screen in the tee or cap openings may be used.

9- For horizontal venting, the vent pipe shall be supported with hangers no more than 3ft. (1m) apart to prevent movement after installation.

10-Clearance to combustible material is 6" (152mm) for single wall vent material except where a listed clearance thimble is used. Clearance to combustible material for type B-1 vent or factory-built chimney is per manufacturer’s instructions. Clearance to combustible material is 1” at the sides, 1” below, and 3” above on horizontal installations of the concentric vent/adapter/cap kit

D-Horizontal Venting-Commercial

1- Horizontal commercial installations are for buildings that are not attached to living spaces. The vent may be single wall vent material installed according to

the sections Venting A-General Recommendations and Requirements and C- Horizontal Venting - General and D-Horizontal Venting - Commercial. Refer to figures 3, 4, and 5. The air inlet may be single wall vent material or U.L. listed single wall flex connector.

2- Refer to table 2 for maximum vent lengths. The vent pipe diameter for horizontal commercial installations shall be 3” (76mm) on 45 units, 4” (100mm) on 60/75 units, 5” (127mm)on 100/125 units.

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