Whirlpool RH8336 Venting requirements, Now start, Vertical roof venting, Horizontal wall venting

Venting requirements

Venting system must terminate to the outside.

Do not terminate the vent in an attic or other enclosed space.

Do not use four-inch laundry-type wall caps.

Do not use plastic vent.

Vent system needed for installation is not included.

It is recommended that the wall or roof cap used have a backdraft damper. If it does, remove the damper from the range hood exhaust connection supplied with the hood.

Determine which outside venting method you need to use.

The length of the vent system and number of elbows should be kept to a minimum to provide efficient performance. The size of the vent system should be uniform. Do Not install two elbows together. Use duct tape to seal all joints in the vent system. Vent system can terminate either through the roof or wall. Use caulking to seal exterior wall or roof opening around exhaust hood. For the most efficient and quiet operation, it is recommended that the range hood be vented vertically through the roof using 7" round vent system.

Flexible metal vent is Not recommended. If it is used, calculate each foot of flexible metal vent as two feet of straight metal vent. Flexible metal elbows count twice as much as standard elbows. Use metal ventwork only.

Figures 1-4 show common venting methods and what types of materials are needed.

Vertical roof venting

roof cap

7" round

through roof

damper located

as far from hood

as possible

66"

Figure 1

Vertical roof venting

roof cap

3-1/4" x 10"

through the roof

3-1/4" x 10"

damper

66"

Figure 2

Horizontal wall venting

3-1/4" x 10"

through the wall

wall cap

66"

Figure 3

Recommended roof venting

roof cap

7" min. diameter round vent

3-1/4" x 10" to round vent transition

Figure 4

Recommended vent system lengths for venting an electric indoor grill

Indoor electric grills produce more smoke than normal cooking and require at least 410 CFM to provide adequate ventilation.

Horizontal wall venting

Use maximum of two feet of 3-1/4" x 10" vent with a wall cap and a free discharge area of 66 square inches. There should be no elbows in vent system between range hood and wall cap.

Vertical roof venting

Use maximum of four feet of 3-1/4" x 10" vent terminating with a roof cap and with a free discharge area of at least 66 square inches.

If longer vent system is required, the shortest possible ventwork length should be used to ensure the maximum CFM of air movement for best venting. A transition to round must be used as close to the hood as possible to eliminate the restriction caused by 3-1/4" x 10" vent. 45° elbows should be used instead of 90° elbows wherever possible. A roof cap providing a free area of 113 square inches is recommended.

Check the length of vent system used with lengths given in the chart to make sure vent system length does not exceed static pressure of .25.

Static pressure vs. vent system length

Static		Equivalent vent system length (ft.)
	CFM	3-1/4" x 10"	7" dia.	8" dia.	9" dia.
pressure
.06	460	4	10	19	34
.10	440	7	17	31	56
.15	417	11	25	47	83
.20	390	15	33	62	111
.25	355	18	42	78
90° elbow		5	11	12	14
45° elbow		2-1/2	5-1/2	6	7

Now start...

With range hood in kitchen.

Slide cardboard or hardboard under range before moving range across floor to prevent damaging floor covering.

Cover countertop, cooktop or set-in range with a thick, protective covering to prevent damaging countertop.

1. Determine which venting method, roof or wall hood venting, you

need to use. The range hood comes shipped for venting through the roof.

2. Disconnect and move freestanding range from cabinet

opening to provide easier access to upper cabinet and rear wall. Put a thick, protective covering over cooktop, set-in range or countertop to protect from damage or dirt. A protective covering will also be needed to set range hood on while getting it ready for installation.

centerline

3. Determine and clearly mark a vertical centerline on the wall and

cabinet in the area the vent opening will be made.

7-1/2"

1-3/8" (from wall)

centerline

4. To wire through top, mark a line

7-1/2" from the right of the centerline on the underside of the cabinet. Mark the point on this line that is 1-3/8" from back wall. Drill a 1-1/4" diameter hole through the cabinet at this point. Note: If a cord-connection kit is used, drill a 1-5/8" diameter hole.

1-3/8" 7-1/2"

centerline

To wire through rear, mark a line 7-1/2" from the right of the centerline on the wall. Mark the point on this line that is 1-3/8" from underside of cabinet. Drill a 1-1/4" diameter hole through wall at this point.

Panel B