20
5 - COMBUSTION AIR AND VENT PIPING
100/115/125/150
Vent
Type
Vent Size
Vent
Material
Intake
(L1)
Exhaust
(L2)
Combined Vent
(L1+L2)
Max Min Max Min Max Min
Twin
Pipe
2"
(60 mm)
Polypropylene
85 ft
(25.9 m)
6 ft
(1.8 m)
85 ft
(25.9 m)
6 ft
(1.8 m)
170 ft
(51.8 m)
12 ft
(3.6 m)
3"
(80 mm)
Polypropylene
49 ft
(15 m)
6 ft
(1.8 m)
147 ft
(45 m)
6 ft
(1.8 m)
196 ft
(60 m)
12 ft
(3.6 m)
Flexible
Exhaust* w/
Rigid 3" PP
Intake
CPVC**
(PVC optional
on intake
ONLY)
Coaxial
Vent Size Material
Natalini DuraVent Centrotherm
Max Min Max Min Max Min
2"/4"
(60 mm/100 mm)
Polypropylene
32.8 ft
(10 m)
6 ft
(1.8 m)
27.88 ft
(8.5 m)
6 ft
(1.8 m)
24.60 ft
(8.5 m)
6 ft
(1.8 m)
3"/5"
(80 mm/128 mm)
*For vertical runs only
**In Canada ULC S636 and in the USA UL1738 schedule 40 CPVC are the only approved Vent Material to be used as
an alternative to Polypropylene venting for the exhaust pipe.
VENT MATERIAL OPTIONS
(Maximum Equivalent Vent Length Shown)
165/205
Vent
Type
Vent Size
Vent
Material
Intake
(L1)
Exhaust
(L2)
Combined Vent
(L1+L2)
Max Min Max Min Max Min
Twin
Pipe
2"
(60 mm)
Polypropylene
85 ft
(25.9 m)
6 ft
(1.8 m)
85 ft
(25.9 m)
6 ft
(1.8 m)
170 ft
(51.8 m)
12 ft
(3.6 m)
3"
(80 mm)
Polypropylene
100 ft
(30.5 m)
6 ft
(1.8 m)
100 ft
(30.5 m)
6 ft
(1.8 m)
200 ft
(60.9 m)
12 ft
(3.6 m)
Flexible
Exhaust* w/
Rigid 3" PP
Intake
CPVC**
(PVC optional
on intake
ONLY)
Coaxial
Vent Size Material
Natalini DuraVent Centrotherm
Max Min Max Min Max Min
2"/4"
(60 mm/100 mm)
Polypropylene
3"/5"
(80 mm/128 mm)
32.8 ft
(10 m)
6 ft
(1.8 m)
32.8 ft
(10 m)
6 ft
(1.8 m)
32.8 ft
(10 m)
6 ft
(1.8 m)
*For vertical runs only
**In Canada ULC S636 and in the USA UL1738 schedule 40 CPVC are the only approved Vent Material to be used as
an alternative to Polypropylene venting for the exhaust pipe
240013375 REV A, [07/01/2021]