EXTERNAL STATIC PRESSURE (IN WC) 2. a. b. C. 4 3 2 -900 RPM 1.40 1 0 800 RPM 700 RPM 600 RPM 500 RPM d. 5000 1100 RPM 1000 RPM 1200 RPM 6000 7000 7500 8000 9000 CFM Name four different types of duct systems. Describe why and where they are used. On the following page, identify each duct system pictured 1) RETURN AIR IN BALANCING DAMPER 2 PERIMETER OUTLET RETURN AIR IN BALANCING 4 FT (1.2 M) MIN. 12 IN (30 CM) MIN. 03109-13 F25.EPS BRANCH DUCTS 15-20 FT (4.6-6.1 M) 24 FT (7.3 M) MAX. MAX. 24' (7.3 M) MAXIMUM Pima Community College | Revised April 2020 4 10000 3) Describe a Furred In Duct System and explain why it is used: Duct systems must be properly to be energy efficient. DAMPER AIR HANDLER Examine the duct system on the next page. Identify the numbered components. 1) 3) 5) 2) Pima Community College | Revised April 2020 5 and