Vent Length And No. Of Elbows - Takagi AT-KJr3U-IN Installation Manual And Owner's Manual

This is a Category III appliance and must be vented accordingly. The vent system must be sealed airtight.
All seams and joints without gaskets must be sealed with high heat resistant silicone sealant or UL listed
aluminum adhesive tape having a minimum temperature rating of 350 °F (177 °C). For best results, a vent
system should be as short and straight as possible.
• This water heater is a Category III appliance and must be vented accordingly with any 4 in. (102
mm) vent approved for use with Category III or Special BH type gas vent.
• Follow the vent pipe manufacturer's instructions when installing the vent pipe.
• Do not common vent this appliance with any other vented appliance. (Do not terminate vent
into a chimney. If the vent must go through the chimney, the vent must run all the way through
the chimney with Category III approved or Special BH vent pipe.)
• When the horizontal vent run exceeds 5 ft. (1.5 m), support the vent run at 3 ft. (0.9 m) intervals
with overhead hangers.
• The maximum length of exhaust vent piping must not exceed 60 ft. (18.3 m).* Deduct 5 ft.
(1.5 m) for each 90° elbow used in the venting system. Do not use more than 6 elbows. A 45°
elbow is equivalent to 2.5 ft. of vent length.
*If vent termination kit 9008900005 is used in the installation, the maximun length of exhaust vent
pipe must not exceed 55 ft. (16.8 m) , and the vent run must not exceed 5 elbows. Vent termination kit
9008900005 also has specific DIP switch settings. Refer to p. 22.
Standard Vent Terminations
Vent type Diameter
Intake 3 in. (76 mm)
Exhaust 4 in. (102 mm)
*For each 90° elbow added, deduct 5 ft. (1.5m) from max. vent length.
Max. Vertical or Horizontal
No. of Elbows
0
1
2
3
Excludes elbow termination, rain caps, or the 4 in. (102 mm) Concentric termination.
Installation with vent termination kit 9008900005
Vent type Diameter
Intake** 3 in. (76 mm)
Exhaust 4 in. (102 mm)
*For each 90° elbow added, deduct 5 ft. (1.5m) from max. vent length.
**For Intake vent, refer to the above table of the installation of 6 elbows and 60 ft.
Max. Vertical or Horizontal
No. of Elbows
0
1
2
Excludes sidewall termination.

-Vent length and No. of Elbows-

(See the next table for vent termination 9008900005.)
Max. No. of Elbows Max. Vertical and Horizontal (Total) Vent Length
6
6
Vent Length
60 ft. (18.3m)
55 ft. (16.8 m)
50 ft. (15.2 m)
45 ft. (13.7 m)
Max. No. of Elbows Max. Vertical and Horizontal (Total) Vent Length
6**
5
Vent Length
55 ft. (16.8 m)
50 ft. (15.2 m)
45 ft. (13.7 m)
19
Page
Installation Manual
60 ft. (18.3 m )*
60 ft. (18.3 m )*
Max. Vertical or Horizontal
No. of Elbows
4 40 ft. (12.2 m)
5 35 ft. (10.7 m)
6 30 ft. (9.1 m)
60 ft. (18.3 m )*
55 ft. (16.8 m )*
Max. Vertical or Horizontal
No. of Elbows
3 40 ft. (12.2 m)
4 35 ft. (10.7 m)
5 30 ft. (9.1 m)
Installation
Vent Length
Vent Length