Additional duct lengths (4" rigid pipe only)
Type of bend
RadiusAdditional duct length
ft
cm
ft
cm
Flexible metal duct
–
3’ 3" (1 m) straight
–
45° angle
–
90° angle
10"
10"
25
25
5’ 11"
4’ 11"
8’ 2"
180
150
250
Smooth metal duct
–
3’ 3" (1 m) straight
–
45° angle
–
90° angle
10"
10"
25
25
3’ 3"
1’ 11"
2’ 7"
100
60
80
Elbow 90° sharp
7’ 6"
230
Concertina bend
–
90° angle
8"
20
2’ 4"
70
Wall vent or window vent
–
with louvers
–
with flap
12’ 5"
4’ 11"
380
150
Exhaust connection
–
left or right side
3’ 3"
100
Installation
32
