Vent pipe diameter and maximum vent length are determined by furnace input
rating as shown in Table.
Model
Size
Input (Btuh)
Flue Exhaust (Vent Pipe) Max. Vent
Pipe
Length
Diameter
Material
090
90,000
3"
PVC
70’
135
135,000
3"
PVC
70'
180
180,000
4"
PVC
70'
225
225,000
4"
PVC
70'
270
270,000
4"
PVC
70'
315
315,000
4”
PVC
50'
360
360,000
4”
PVC
50'
400
400,000
(2) 4”
PVC
(2) 70'
450
450,000
(2) 4”
PVC
(2) 70'
540
540,000
(2) 4”
PVC
(2) 70'
630
630,000
(2) 4”
PVC
(2) 50'
720
720,000
(2) 4”
PVC
(2) 50'
