User Manual

DUCT
PIECES
EQUIVALENT NUMBER
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.
WORKSHEE
T—CA
LCUL
AT
E
TOTAL EQUIVALENT DUCTWORK LENGTH
DUCT
EQUIVALENT NUMBER
PIECES LENGTH
X USED
=
TOTAL
6″ Ro und 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″ Ro und
9 Ft.
x ( ) =
Ft.
to
3
1
⁄4″ x 10″
rect.
trans iti
on
90° elbow
7″ Ro und,
14 Ft.
x ( ) =
Ft.
90° elbow
7″ Round ,
9 Ft.
x ( ) =
Ft.
45° elbow
7″ Round
28 Ft.
x ( ) =
Ft.
wall cap
( 21 f
t. w/o
with damper)
x ( ) =
Ft.
damper
7″ Round
39 Ft.
x ( ) =
Ft.
r oof cap
7″ Round 1 Ft.
x (
) =
Ft.
to
3
1
⁄4″ x 10″
rect.
transition
7″ Round
5 Ft.
x ( ) =
Ft.
t o
3
1
⁄4″ x
10″
rect.
transiti
on,
90° elbow
Subtota
l column 2 =
Ft.
Subtota
l column 1 =
Ft.
Total du
ctwork
=
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.
NOTE: Any home ventilation system, such as a ventilation
hood, may interrupt the proper flow of combustion air and
exhaust required by fireplaces, gas furnaces, gas water
heaters and other naturally vented systems. To minimize
the chance of interruption of such naturally vented systems,
follow the heating equipment manufacturer’s guidelines and
safety standards such as those published by NFPA and
ASHRAE. When applicable, install any makeup
(replacement) air system in accordance with local building
code requirements.
7