Noritz NRCB180DV - Page 23

23
Here
[DIP Switch Adjustment]
Vent length condition
DIP switches
#7 #8
①Less than 33 ft using 2 in. (50 mm) pipe
 
②33 ft or more using 2 in. (50 mm) pipe
 
③Less than 50 ft using 3 in. (75 mm) pipe
 
④50 ft or more using 3 in. (75 mm) pipe
 
ON =  / OFF = 
[Vent length Calculation example]
Step 1:
Vent Diameter
2 in.
Step 2:
Straight pipe length
(Vertical length + Horizontal length)
17 ft
Step 3:
Number of elbows
90° elbows: 2
45° elbows: 2
Step 4:
Calculate equivalent length
90° elbows: 2 × 5 ft = 10 ft
45° elbows: 2 × 3 ft = 6 ft
Step 5:
Total vent length
(Add Step 2 and Step 4 together)
17 ft + 16 ft = 33 ft
Step 6:
Check [DIP Switch Adjustment] and select DIP
switch settings.
②[33 ft or more using 2 in. (50 mm) pipe]
(i.e., turn ON DIP switch #7)
Maximum Vent Length Configurations (For flexible
pipe for chimney)
[DuraVent® - Flex Through Chimney w/ Air Intake
(Only 3 in.)]
The vent length condition setting depends on
the flexible pipe length, the rigid pipe length and
number of elbows. Calculate an each ventilation
system equivalent length, then adjust the DIP
switch.
Vent
length
condition
DIP
switch
#7
Maximum equivalent
vent length*
V (Vertical)
+
H (Horizontal)
Equivalent
length
Short
length

< 50 ft (15 m)
Flexible pipe:
1 ft (0.3 m)
Rigid pipe:
1 ft (0.3 m)
90° elbow:
5 ft (1.5 m)
45° elbow:
3 ft (0.9 m)
Long
length

50 ft (15 m)–75 ft (22.5 m)
ON =  / OFF = 
* The maximum vent length includes elbows.
Here
• Equivalent vent length calculation example:
[Example 1]
- Vent Size: 3 in.
- V (Vertical length): 20 ft
- H (Horizontal length): 6 ft
- 90° elbow: 2
1 ft × 20 + 1 ft × 6 + 5 ft × 2 = 36 ft
 
Select “Short length”
[Example 2]
- Vent Size: 3 in.
- V (Vertical length): 35 ft
- H (Horizontal length): 10 ft
- 90° elbow: 3
1 ft × 35 + 1 ft × 10 + 5 ft × 3 = 60 ft
 
Select “Long length”
Venting the Combi Boiler