A vapor compression heat pump cycle requires that the evaporator and condenser operate within 10°C of their respective heat reservoirs. The cycle employs R134a as the working fluid, which exits the evaporator as a saturated vapor and exits the condenser as a saturated liquid. The compressor operates with an isentropic efficiency of 82%. If the desired inside temperature is 21 °C and the outside temperature is 0 °C, determine:

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.