Dacor ER48D Planning Guides - Page 2

Document # PG08-001 ERV30, ERV36, ERV48, PRV30, PRV36, PRV46 30", 36", 46", 48" Wide, Slim Raised Vent Revised 03/29/10 Page 2/3 PLANNING GUIDE 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 from the Blower Maximum Duct Straight Length. Raised Vent Model No. ERV/PRV30 ERV/PRV36 PRV46 ERV48 Approved Dacor Blowers* Remote blowers: REMP3 or REMP16 In-line blowers: ILHSF8 or ILHSF10 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. *For detailed information on the remote/in-line blowers, refer to the blower installation instructions. 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) Specifications subject to change without notice. Install all appliances according to accompanying installation instructions. www.Dacor.com Phone: (800) 793-0093 8.2