Jenn-Air JED3430GB Installation Guide - Page 5

For Best Performance: ■■ Use 26-gauge minimum galvanized or 25-gauge minimum aluminum metal vent. Poor quality pipe fittings can reduce airflow. Flexible metal vent is not recommended. NOTE: Local codes may require a heavier gauge material. ■■ Metal duct may be reduced to 30-gauge galvanized steel or 26-gauge aluminized steel if allowed by local codes. This reduction is based on information in the International Residential Codes Section M1601.1 (2006 edition). ■■ Do not install 2 elbows together. ■■ Use no more than three 90° elbows. ■■ If an elbow is used, install it as far away as possible from the hood's vent motor exhaust opening. ■■ Make sure there is a minimum of 18" (45.7 cm) of straight vent between the elbows if more than one elbow is used. ■■ Elbows too close together can cause excess turbulence that reduces airflow. ■■ Do not use a 5" (12.7 cm) elbow in a 6" (15.2 cm) or 31/4" x 10" (8.3 cm x 25.4 cm) system. ■■ Do not reduce to a 5" (12.7 cm) system after using 6" (15.2 cm) or 31/4" x 10" (8.3 cm x 25.4 cm) fittings. ■■ Avoid forming handmade crimps. Handmade crimps may restrict airflow. ■■ Use a vent cap for proper performance. If an alternate wall or roof cap is used, be certain the cap size is not reduced and that it has a backdraft damper. ■■ Use vent clamps to seal all joints in the vent system. ■■ Use caulking to seal exterior wall or roof opening around the cap. The length of vent system and number of elbows should be kept to a minimum to provide efficient performance. The maximum equivalent length of the vent system is 60 ft (18.3 m). For altitudes above 4,500 ft (1372 m), reduce recommended vent run by 20% for best performance. Cold Weather Installations An additional backdraft damper should be installed to minimize backward cold air flow. Makeup Air Local building codes may require the use of makeup air systems when using ventilation systems greater than specified CFM of air movement. The specified CFM varies from locale to locale. Consult your HVAC professional for specific requirements in your area. Venting Methods Common venting methods are shown for a counter-mounted downdraft cooktop. The cooktop may be vented through the wall or floor. Option 1 - Roof Venting Option 2 - Wall Venting B B A A A. 6" (15.2 cm) round roof venting A. 6" (15.2 cm) round wall venting B. Roof cap B. Wall cap Option 3 - Venting Between Floor Joists Option 4 - Venting Behind Cabinet Kick Plate 3¼" x 10" A (8.3 cm x 25.4 cm) B A B A. Wall cap A. Wall cap B. 6" (15.2 cm) round wall venting B. 6" (15.2 cm) round wall venting 5