Additional duct lengths (4" rigid pipe only)Type of bend Radius Additional 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
35