Dacor IVS2 Installation Instructions - Page 7

Installation Planning • To prevent back-drafts, a damper at the duct outlet may Calculating the Maximum Duct Run Length also be required. The IVS comes equipped with a backdraft damper installed in the collar of the unit. The maximum straight duct length for the hood is determined by the type of duct used. See the chart below. • Make sure duct work does not interfere with floor joists or wall studs. DUCT SIZE MAXIMUM DUCT RUN • The hood exhaust connects to a 8-inch round duct. You 8 inch round 60 feet can increase the duct size over the duct run if desired. 10 inch round 50 feet To prevent a back draft, never decrease the duct size over the run. If existing duct work is smaller than 8 inches in diameter, remove it and replace it with 8-inch or 10-inch duct work. • On dual exhaust models, the two 8 inch exhausts may be merged into on 10 inch duct using Dacor transition ATD10. 3¼" X 10" rectangular 50 feet For each elbow and transition added to the duct work, a certain number of feet must be subtracted from the maximum duct run to compensate for wind resistance. To determine the length the duct work cannot exceed, subtract all of the equivalent lengths of the elbows and transitions listed below from the maximum duct run above. 10 inch round Duct Work Equivalent Lengths 2" (5.1 cm) 13" (33.0 cm) 21" (53.3 cm) Transition Model ATD10 8" (20.3 cm) • Do not rely on tape alone to seal duct joints. Fasten all connections with sheet metal screws and tape all joints with certified silver tape or duct tape. Use sheet metal screws as required to support the duct weight. • Do not use flexible metal duct. • Do not use duct work that is smaller in cross-sectional area than 8-inch round duct. Additional Requirements for Models IVSR1 and IVSR2: Models IVSR1 and IVSR2 are not equipped with an internal blower. Installation of an in-line or remote blower is required. See the table below for the correct model number. DUCT WORK SIZE 8 inch 10 inch IN-LINE BLOWER MODEL ILHSF8 ILHSF10 REMOTE BLOWER MODEL REMP3 REMP16 PIECE 8" 90° elbow 8" 45° elbow SUBTRACT 7 feet 3 feet PIECE 10" 90° elbow 10" 45° elbow SUBTRACT 5 feet 2 feet 3¼" X 10" to round 90° transition 25 feet 3¼" X 10" to 8"/10" round transition 4 feet 3¼" X 10" 90° elbow 3¼" X 10" 45° elbow 15 feet 7 feet 3¼" X 10" 90° flat elbow Wall cap with damper 20 feet * Roof cap * * The equivalent lengths of roof and wall caps vary with model and configuration. For equivalent length, contact the manufacturer or a qualified HVAC specialist. Duct Work Design Tips When planning new duct work, always look for the shortest, most direct route to the outside. Wherever possible, reduce the number of transitions and turns to as few sharp angles as possible. Two staggered 45° angles are better than one 90°. Keep turns as far away from the hood exhaust as possible, and as much space between bends as possible. For best performance, use round duct instead of rectangular, especially when elbows are required. If multiple elbows are used, try to keep a minimum of 24 inches of straight duct between them. Avoid "S" or "back to back" use of adjacent elbows. In regions where the weather gets extremely cold, use thermal breaks, such as a short section of non-metallic duct, to avoid indoor heat loss. Locate the break as close as possible to the outside pass through point. 5