Kenmore 721.80042 Standard Fittings, Duct Length, transition, 2 90 elbows, 20 ft, wall cap, 40 ft

STEP 2:

PREPARE THE VENTING SYSTEM

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 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.

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

90 ° elbow = 1Oft.	3-1/4"x10" wall cap	45 ° elbow = 5ft.	3-1/4"x10" fiat elbow
	= 40ft.		= 1Oft.

Figure 9

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

					Exam	)les
	For 3-1/4"x10"		SYSTEMS			For	6" ROUND SYSTEMS
3-1/4"x10"		_	6ft. _	wall cap		90°elbows	_---	6ft. -_/wall	cap
90 ° elbow *_fr_				I 0_"
						transi_
1 3-1/4" x 10"		90° elbow		=	25ft.	1 transition		=	5 ft.
						2 90 ° elbows		=	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.