KitchenAid 42 installation instructions Venting methods, Calculating the vent system length

Venting methods

Vertical venting Horizontal venting

This canopy range hood is factory set for vertical venting. For rear vent applications, the blower must be turned inside the range hood so that the blower vents to the rear as indicated. The blower is turned by removing two screws on each side of the blower, rotating the blower with the exhaust opening facing the rear and then replacing the screws. The exhaust cover(s) must be moved to block the unused opening(s). The blower must be converted before installing the range hood.

Vent system needed for installation is not included. The 36" (91.4 cm) and 42" (106.7 cm) models have one exhaust opening. 3-1/4" x 10" (8.3 cm x 25 cm) rectangular, 7" (17.8 cm) round, 8" (20.3 cm) round, 9" (22.9 cm) round, or 10" (25.4 cm) round vent may be used. The hood exhaust opening is 3-1/4" x 10" (8.3 cm x 25 cm).

The 48" (121.9 cm) model has two 3-1/4" x 10" (8.3 cm x 25 cm) exhaust openings. It is recommended that Vent Transition Kit No. 8284757 be used to transition the two openings into one 10" (25.4 cm) round vent. (Cannot be

roof cap

3-1/4" x 10"

(8.3 cm x 25 cm)

vertical venting

(roof or wall)

3-1/4" x 10"

(8.3 cm x 25 cm) horizontal venting

wall cap

used with Chimney Extension Kit No. 8284754.)

Vent system can terminate either through the roof or wall.

The vent system length should not exceed the lengths shown in the chart.

Vent size	Maximum length
3-1/4" x 10" (8.3 cm x 25 cm)	35 ft. (10.7 m)
7" (17.8 cm) round	40 ft. (12.2 m)
8" (20.3 cm) round	50 ft. (15.2 m)
9" (22.9 cm) round	60 ft. (18.3 m)
10" (25.4 cm) round	60 ft. (18.3 m)

Calculating the 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.

Vent Piece	3-1/4" x 10" (8.3 cm x 25 cm)	7" (17.8 cm), 8" (20.3 cm),
	Rectangular	9" (22.9 cm), 10" (25.4 cm)
		Round
45° elbow	7.0 feet	2.5 feet
	(2.1 m)	(0.8 m)
90° elbow	5.0 feet	5.0 feet
	(1.5 m)	(1.5 m)
90° flat elbow	12.0 feet
	(3.7 m)
transition to round	5.0 feet
	(1.5 m)
wall cap	0.0 feet
	(0.0 m)

Example for 3-1/4" x 10"

(8.3 cm x 25 cm) vent system

3-1/4" x 10”	wall
(8.3 cm x 25 cm)	cap
elbow	6 ft. (1.8 m)

2ft.

(0.6 m)

Maximum length	= 35 ft. (10.7 m)
1 — 90° elbow	=	5 ft.	(1.5 m)
8 ft. (2.4 m) straight	=	8 ft.	(2.4 m)
1 — wall cap	=	0 ft.	(0 m)
Length of 3-1/4" x 10"
(8.3 cm x 25 cm)
system	= 13 ft.		(4 m)

Note: Flexible vent is Not recommended.

Flexible vent creates back pressure and air turbulence that greatly reduces performance.

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