GE JGP389 Plan the Duct RUN, Install the Ductwork, General Considerations

STEP 8

PLAN THE DUCT RUN

1.Make a sketch of the total system. Identify the type of each fitting and the length of straight pipe.

2.Enter your run into the Duct Length Chart in this guide. Elbows, wall caps and other fittings are shown in the chart with their equivalent straight duct length. Each fitting value must be added to the amount of straight duct length used to determine the overall straight duct equivalent length. Use the following examples as a guide.

3.Using good quality ducting material, install per these instructions. A few minutes and pennies spent now will pay long term dividends for the life of the cooktop.

STEP 9

INSTALL THE DUCTWORK

•Ducting must conform to local code materials and “make-up” requirements—300 CFM minimum.

•IMPORTANT: Save for local electrical inspector’s use.

•Ducting a cooktop is easy but critical for proper performance.

•After reading these instructions, plan the

duct run.

•Use the “Duct Length Chart” to find the equivalent length of the run.

•Shift the blower to “high range” if indicated (done by snapping the “restricter ring” out of the blower inlet). Be sure blower is not running.

•Install the duct hardware.

IMPORTANT

Total allowance duct system is: 90' with 6" round wall cap 80' with 31⁄4"x10" wall cap

Low range is up to 60' High range is 61 to 90'

GENERAL CONSIDERATIONS:

1.Use 6" diameter round or 31⁄4"x10" rectangular only except as follows: For gas models, 5" diameter round must be used if the straight duct length is 10 feet or less, using 5" round wall cap.

2.Do not use 5" elbows except in a 5" system. Instead, use a 5" to 6" transition followed by a 6" elbow, or a 5" to 31⁄4"x10" elbow transition.

3.Use quality metal duct of at least 26 gauge galvanized or 24 gauge aluminum. Inferior quality pipe and fittings can cause up to twice the restriction shown and is a poor value. See the Prepare for Duct Work section of this guide for optional under-slab ducting. Local codes may require a heavier gauge material or restrict PVC.

4.Distance between adjacent fittings (elbows, transitions, etc.) should be at least 18". The farther the better. Closer distance promotes turbulence which reduces airflow.

5.The number of downstream elbows or transitions should be limited to three. The initial 5" to 6" straight transition, if used, need not be counted in this number.

6.Handmade crimps are likely to cause restrictions.

7.If an alternate wall or roof cap is used, be certain duct size is not reduced, and that there is a backdraft damper. It is best to use listed caps to be certain of proper performance.

8.Thermal breaks: In areas of extreme cold

weather, it may be necessary to provide a short length of nonmetallic duct as close to the wall as possible, to prevent conduction along the metal duct.

9.High altitude installations: It is advisable to reduce allowable duct run by 20%.

10.Follow the duct calculation in this guide carefully for best performance and satisfaction.

STEP 10

SHIFTING THE BLOWER FROM “LOW RANGE” TO “HIGH RANGE”

This cooktop is equipped with a dual range blower. It is shipped from the factory in Low Range for most installations. If the Equivalent Duct Length exceeds 60 feet it must be shifted to High range. Do not shift to high range for shorter lengths. This will cause excessive noise, conditioned air loss and affect the flame pattern on gas burners.

To shift to High Range, be sure the blower is stopped. Remove the air grill. Remove the filter and intake guard. Pop the spring loaded “restricter ring” out of the blower inlet. Replace the intake guard, grill and filter.

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