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2. (10 points) A hot-water system (shown in Figure a) consists of a boiler three air-handling units (AHUS). Copper pipes and fittings are used. The total heat load for all three AHUs is 1,400,000 BTUh. The maximum pressure required to pump water through the AHU which has the highest pressure drop of 40 ft in total head. The inlet and outlet temperatures at the AHUs are designed to be 160°F and 120°F, respectively. a. What is the total required flow rate in GPM? b. Allowing for 20% extra capacity for load pickup, what should be the boiler capacity? c. Use Figure c below. What should be the size of the main pipe, based on a flow velocity of 4.5 FPS (feet per second)? Draw lines or mark on the diagram to indicate how you arrive at your answer. d. Use Figure b below. What is the size of the impeller required for this pump operating at this condition? Draw lines or mark on the diagram to indicate how you arrive at your answer. e. What is the brake horsepower required at this operating condition? Draw lines or mark on the diagram to indicate how you arrive at your answer.

ANU- AMU- AMUS BOLER PUMP (a) 50 10 Total head, 30 LITER 20 10 NPSH NOURED 100 150 Capacity in U.S.gallons per minute 30 20 HEAD LOSS, f/100 ft BATER BODEC SIZES 0.5 0.2 100 200 300 400 630 000 2000 3000 2 3 4 6 810 20 30 40 60 000 FLOW RATE, U.S.gal/min (c)