7
Calculating Vent System Length
To calculate the length of the system you need, add the
equivalent feet (meters) for each vent piece used in the system.
6" (15.2 cm) or Larger Round Vent System
Example vent system
3¹⁄₄
" x 10" (8.3 cm x 25.4 cm) Vent System
Example vent system
Vent Piece
Round
45° elbow
2.5 ft
(0.8 m)
90° elbow
5.0 ft
(1.5 m)
6" (15.2 cm) or larger
wall cap
0.0 ft
(0.0 m)
3
¹⁄₄
" x 10" (8.3 cm x 25.4 cm)
to 6" (15.2 cm) or larger
4.5 ft
(1.4 m)
3
¹⁄₄
" x 10" (8.3 cm x 25.4 cm)
to 6" (15.2 cm) or larger
90° elbow
5.0 ft
(1.5 m)
Maximum Recommended Length
= 50 ft (15.2 m)
1 - 90° elbow
= 5.0 ft (1.5 m)
1 - wall cap
= 0.0 ft (0.0 m)
8 ft (2.4 m) straight
= 8.0 ft (2.4 m)
Length of 7" (17.8 cm) system
= 13.0 ft (3.9 m)
Wall cap
90˚ elbow
2 ft (0.6 m)
6 ft (1.8 m)
Vent Piece
3
¹⁄₄
" x 10" (8.3 cm x 25.4 cm)
90° elbow
5.0 ft
(1.5 m)
3
¹⁄₄
" x 10" (8.3 cm x 25.4 cm)
flat elbow
12.0 ft
(3.7 m)
3
¹⁄₄
" x 10" (8.3 cm x 25.4 cm)
wall cap
0.0 ft
(0.0 m)
Maximum Recommended Length
= 35 ft (10.7 m)
1 - 90° elbow
= 5.0 ft (1.5 m)
8 ft (2.4 m) straight
= 8.0 ft (2.4 m)
1 - wall cap
= 0.0 ft (0.0 m)
Length of 3
¹⁄₄
" x 10" (8.3 cm x 25.4 cm)
system
= 13.0 ft (3.9 m)
Wall cap
3
¹⁄₄
" x 10"
(8.3 x 25.4 cm)
elbow
2 ft
(0.6 m)
6 ft (1.8 m)
