Bosch Appliances HMV9302, HMV9305, HMV9306, HMV9307 5 ft, 8 ft, 8 ft, 25 ft, 20 ft, 40 ft, 40 ft, 73 ft, 73 ft, Figure, Examples, 1-WallCap, 1-WallCap, DUCT LENGTH, 1-transition, 2-90o elbows, TOTAL LENGTH

STEP 2:

PREPARE THE VENTING SYSYTEM

STANDARD FITTINGS

NOTE: If the existing duct is round, you must use a rectangular-to-round adapter, with a rectangular 3" extension duct installed between the damper assembly and the adapter to prevent the exhaust damper’s sticking.

DUCT LENGTH

The total length of the duct system, including straight duct, elbows, transitions, wall or roof caps must not exceed the equivalent of 140 feet.

For best performance, do not use more than three 90 degree elbows.

Below are the standard fittings and their equivalent length in feet.

1 2 3

	3 1/4"x10"	3 1/4"x10" roof	3 1/4"x10" 90˚
	to 6"=5ft.	cap=24ft.	elbow=25ft.
4	5	6	7

	3 1/4"x10"		3 1/4"x10"
90o elbow	wall cap	45o elbow	flat elbow
=10ft.	=40ft.	=5ft.	=10ft.

Figure 9

To calculate the equivalent length of each ductpiece used, see the examples below.

				Examples
For 3 1/4"x10" SYSTEMS					For 6" ROUND SYSTEMS			wall cap
3 1/4"x10"					90o elbows		6ft.
		6ft.	wall cap
90o elbow
					transition	2ft.
	2ft.
					1-transition		=	5 ft.
1-3 1/4" x 10" 90o elbow			=	25 ft.
					2-90oelbows		=	20 ft.
1-Wall Cap			=	40 ft.	1-Wall Cap		=	40 ft.
8 feet straight duct			=	8 ft.	8 feet straight		=	8 ft.
TOTAL LENGTH			=	73 ft.	TOTAL LENGTH		=	73 ft.

9