Installation instructions – GE JV247 User Manual
Page 7
7
DUCT
EQUIVALENT NUMBER
PIECES
LENGTH
x USED
= TOTAL
3
1
⁄
4
″x 10″
1 Ft.
x ( )
=
Ft.
Rect.,
straight
7
″ Round,
1 Ft.
x ( )
=
Ft.
straight
6
″ Round,
1 Ft.
x ( )
=
Ft.
straight
3
1
⁄
4
″x 10″
14 Ft.
x ( )
=
Ft.
Rect. 90°
elbow
3
1
⁄
4
″x 10″
8 Ft.
x ( )
=
Ft.
Rect. 45°
elbow
3
1
⁄
4
″x 10″
33 Ft.
x ( )
=
Ft.
Rect. 90°
flat elbow
3
1
⁄
4
″x 10″
24 Ft.
x ( )
=
Ft.
Rect.
(18 ft. w/o
wall cap
damper)
x ( )
=
Ft.
with
damper
3
1
⁄
4
″x 10″
2 Ft.
x ( )
=
Ft.
Rect. to
6
″ round
transition
3
1
⁄
4
″x 10″
4 Ft.
x ( )
=
Ft.
Rect. to
6
″ round
transition
90° elbow
6
″ Round,
25 Ft.
x ( )
=
Ft.
90° elbow
6
″ Round,
16 Ft.
x ( )
=
Ft.
45° elbow
Subtotal column 1
=
Ft.
WORKSHEET—CALCULATE TOTAL EQUIVALENT DUCTWORK LENGTH
DUCT
EQUIVALENT
NUMBER
PIECES
LENGTH
x USED
= TOTAL
6
″Round 53 Ft.
x ( )
=
Ft.
wall cap
(39 ft. w/o
with
damper)
x ( )
=
Ft.
damper
6
″ Round 72 Ft.
x ( )
=
Ft.
roof cap
6
″ Round 3 Ft.
x ( )
=
Ft.
to
3
1
⁄
4
″x 10″
rect.
transition
6
″ Round 9 Ft.
x ( )
=
Ft.
to
3
1
⁄
4
″x 10″
rect.
transition
90° elbow
7
″ Round, 14 Ft.
x ( )
=
Ft.
90° elbow
7
″ Round, 9 Ft.
x ( )
=
Ft.
45° elbow
7
″ Round 28 Ft.
x ( )
=
Ft.
wall cap
(21 ft. w/o
with
damper)
x ( )
=
Ft.
damper
7
″ Round 39 Ft.
x ( )
=
Ft.
roof cap
7
″ Round 1 Ft.
x ( )
=
Ft.
to
3
1
⁄
4
″x 10″
rect.
transition
7
″ Round
5 Ft.
x ( )
=
Ft.
to
3
1
⁄
4
″x 10″
rect.
transition,
90° elbow
Subtotal column 2
=
Ft.
Subtotal column 1
=
Ft.
Total ductwork
=
Ft.
Installation Instructions
MAXIMUM DUCT LENGTH: For satisfactory air movement,
the total duct length of a 3
1
⁄
4
″ x 10″ rectangular, 7″ diameter
round duct should not exceed 65 equivalent feet.