Ductulator Questions and Answers PDF

Ductulator Questions and Answers 1. One side of a rectangular duct is 14 inches. The cfm's are 2,000. The friction (head) loss is.1 inch per 100 ft of duct. The duct size is __________. A. 14 x 20 B. 14 x 18 C. 14 x 25 D. 20...

Ductulator Questions and Answers 1. One side of a rectangular duct is 14 inches. The cfm's are 2,000. The friction (head) loss is.1 inch per 100 ft of duct. The duct size is __________. A. 14 x 20 B. 14 x 18 C. 14 x 25 D. 20 x 15 2. The cfm's are 2,500. The friction (head) loss is.28 inch per 100 ft of duct. The diameter of a round duct would be __________ inches. A. 12 B. 14 C. 16 D. 18 3. A 20 x 11-inch duct with a friction (head) loss of.05 inch per 100 ft of duct will deliver __________ cfm's. A. 3,600 B. 2,000 C. 1,500 D. 1,000 4. The velocity is 1,100 fpm. The cfm's are 2,400. The friction (head) loss per 100 ft of duct is __________ inch. A..9 B..7 C..09 D. 1.1 5. The friction (head) loss is.07 inch per 100 ft of duct. The air flow is 5,000 cfm. The diameter of a round duct would be __________ inches. A. 20 B. 22 C. 28 D. 30 6. The minimum diameter of a round duct required to convey 9000 cfm standard air at a velocity of 2400 fpm is __________ inches. A. 24 B. 26 C. 28 D. 30 7. A rectangular 40" x 20" duct may be replaced with a __________-inch diameter round duct. A. 20 B. 25 C. 30 D. 35 8. For certain installations, an equivalent rectangular duct is to be installed in lieu of a round duct 20" in diameter. If one side of the rectangular duct is 11 inches, the other side would be __________ inches. A. 20 B. 25 C. 35 D. 40 9. The estimated velocity of the air through a 14-inch round duct conveying 750 cfm is __________ fpm. A. Less than 675 B. Between 675 and 725 C. Between 726 and 775 D. More than 775 10. The capacity of a 40" x 12" rectangular duct is equivalent to a __________-inch round duct. A. 16 B. 20 C. 23 D. 26 11. The estimated friction (head) loss in a 100-foot section of duct 40 inches wide by 12 inches high with a mean velocity of 2000 fpm is __________ inches. A. Between 0.10 and 0.15 B. Between 0.15 and 0.20 C. Between 0.20 and 0.25 D. Between 0.25 and 0.30 12. The minimum size round duct required to convey 5000 cfm of standard air at a velocity of 1000 fpm is __________ inches. A. 24 B. 26 C. 28 D. 30 13. For a certain installation, an equivalent rectangular duct is to be installed in lieu of a round duct 23" in diameter. If the short side of the duct is 12 inches, the dimension of the long side is __________ inches. A. 28 B. 32 C. 36 D. 40 14. The round equivalent of a 20" x 20" rectangular duct is __________ inches. A. 18 B. 20 C. 22 D. 24 15. The estimated friction head loss through a 38-inch round galvanized steel duct 125 feet long which operates with a 12,000-cfm flow is __________ inches. A. 0.075 B. 0.093 C. 0.125 D. 1.210 16. Fifty feet of supply air duct 40 inches wide and 20 inches high has an airflow of 8000 cfm. The friction head loss would be __________ inches. Select the closest answer. A. 0.025 B. 0.055 C. 0.075 D. 0.100 17. There is an airflow of 3000 cfm in 20-inch round duct 250 feet long. The friction (head) loss in the duct is __________ inches. Select the closest answer. A. 0.12 B. 0.22 C. 0.30 D. More than 0.30 18. A duct has a friction (head) loss of.045 inch per 100 feet of duct. If the duct is carrying 9500 cfm, the round duct size is __________ inches. Select the closest answer. A. 12 B. 20 C. 34 D. 38 ****Please see Answer Key on the following page**** 3/17/22  Ductulator Questions and Answers Answer Key Answer 1. A 2. C 3. D 4. C 5. C 6. B 7. C 8. C 9. B 10. C 11. D 12. D 13. D 14. C 15. B Chart is head loss per 100ft is.075 - have to adjust for 125 ft.075 ÷ 100 ft = x ÷ 125 ft x =.093 16. B 17. D Chart head loss per 100 ft is.13 – have to adjust for 250 ft.13 ÷ 100 = x ÷ 250 x =.325 18. D