Design Guide

VENTILATION | PLANNING INFORMATION
1.800.735.4328 | THERMADOR.COM
219
EQUIVALENT DUCT LENGTHS FOR COMMONLY USED TRANSITIONS
PLANNING INFORMATION
DUCT PIECE
SIZE
OF DUCT
PIECE (IN.)
EQUIVALENT
LENGTH (FT.)
Smooth Straight
6 1.2
7 0.95
8 0.7
10 0.6
3
1
/
4
" x 10"
Straight
N/A 1
3
1
/
4
" x 14"
Straight
N/A 0.7
90° Elbow Round
6 12
7 8
8 6
45° Elbow Round
6 5
7 4
8 3
3
1
/
4
" x 10"
90° Elbow Round
N/A 5
3
1
/
4
" x 10"
45° Elbow Round
N/A 15
3
1
/
4
" x 10"
Flat Elbow
N/A 20
Round to
3
1
/
4
" x 10"
6 1
7 1
3
1
/
4
" x 10"
to Round
6 5
7 3
Round to
3
1
/
4
" x 10"
90° Elbow
6 10
7 8
DUCT PIECE
SIZE
OF DUCT
PIECE (IN.)
EQUIVALENT
LENGTH (FT.)
3
1
/
4
" x 10" to
Round 90° Elbow
6 10
7 5
3
1
/
4
" x 10"
Center Reverse
Elbow Left
N/A 15
3
1
/
4
" x 10"
Center Reverse
Elbow Right
N/A 25
3
1
/
4
" x 10" Left
Reverse Elbow
N/A 15
3
1
/
4
" x 10"
Right Reverse
Elbow
N/A 25
Round Wall Cap
6 2
7 2
8 2
10 2
Round Roof Cap
6 2
7 2
8 2
2' Long
3
1
/
4
" x 10" Flex
N/A 20
3
1
/
4
" x 10"
to Round
10 1
7" Inline
Backdraft Damper
7
3
1
/
4
" x 10" Roof
Jack and Shutter
N/A
NOTE: These commonly used installation parts can be purchased at a
local hardware store. Thermador does not manufacture all these parts.