Dacor ERV48 Installation Instructions - Page 9

Installation Specifications • On side exhaust installations, allow five inches of space on the side for the ADT2 exhaust transition plus additional space for the duct attached to it (X). • Make sure duct work does not interfere with floor joists or wall studs. • With concrete slab construction, "box-in" the duct work and blower wiring to prevent collapsing or other damage when the wet concrete is poured. • Cross-drafts or air currents from adjacent open windows or doors, heating/air conditioning outlets, ceiling fans and recessed ceiling lights reduce vent efficiency. X 5" ATD2 Duct Work Design Tips • 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, with as much space between each bend as possible. • For best performance, use round duct instead of rectangular when possible, especially when elbows are required. • If multiple elbows are used, try to keep a minimum of 24" of straight duct between them. Avoid "S" or "back to back" configurations of adjacent elbows. • Do not use flexible metal duct. Calculating the Maximum Duct Run Length • Do not use duct work that is smaller in cross-sectional area than the required duct sizes in the table to the right. • For best performance, keep the duct run as short as possible and never exceed the maximums stated at the right. • The maximum straight duct length for the raised vent system depends on the model of remote or in-line blower used with the vent system and the number of elbows and transitions used. The Equivalent Number of Feet for each elbow and transition (see table) must be subtracted from the maximum straight length to compensate for wind resistance. To determine the maximum allowable length of the duct work, subtract all of the equivalent lengths of the elbows and transitions listed at the right from the Blower Maximum Duct Straight Length. For example, for a raised vent system using 3 1/4" X 10" rectangular duct, two (2) 3 1/4" X 10" 90° elbows, a 3 1/4" X 10" rectangular to 10" round transition, and a REMP16 remote blower: • From the Blower Maximum Duct Straight Length table, the maximum length without transitions and elbows is 60 feet. • The equivalent length of each 90° elbow is 15 feet. • The equivalent length of 45° elbow is 2 feet. • The equivalent length of the transition is 4 feet. • The total equivalent length of the above components is: 15 feet + 15 feet + 4 feet + 2 feet = 36 feet. • The maximum amount of straight duct that can be used with a REMP16 and the above components is: 60 feet 34 feet = 24 feet. Equivalent Number of Feet Duct Elbows and Transitions 45° elbow 8 Inch 3 feet 3 ¼" X 10 45° elbow 7 feet 45° elbow 10 Inch 2 feet 3 ¼" X 10 90° elbow 15 feet 90° elbow 8 Inch 7 feet 3 ¼" X 10 90° flat elbow 20 feet 90° elbow 10 Inch" 5 feet 3 ¼" X 10 to 8" round transition 4 feet 90° 3 ¼" X 10 to 8" round transition 25 feet 3 ¼" X 10 to 10" round transition 4 feet Roof cap * Wall 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 Size Used 8 Inch 10 Inch 3 ¼" X 10" REMP3 Remote Blower 50 feet (15.2 meters) 40 feet (12.2 meters) 40 feet (12.2 meters) Blower Maximum Duct Straight Length REMP16 Remote Blower ILHSF8 In-line Blower 60 feet (18.3 meters) 50 feet (15.2 meters) 70 feet (21.3 meters) 40 feet (12.2 meters) 60 feet (18.3 meters) 40 feet (12.2 meters) ILHSF10 In-line Blower 60 feet (18.3 meters) 70 feet (21.3 meters) 60 feet (18.3 meters) 7