Ahydronic system is proposed for a 20-story building, with the chilled water pump located on the lowest floor and makeup water at the top floor. each story is 15 ft (4.6 m), and the makeup water pressure is 15 psi (103 kpa). the main air handlers are located on the top floor, and a variety of terminal units on each floor. the total piping friction loss is 60 ft of head (179 kpa). what is the static head of the chilled water system at the pump while turned off? 75 psi (517 kpa) a. b. 115 psi (793 kpa) c. 145 psi (1000 kpa)

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.