Aheat pump is used to maintain a room in hospital at 23°c on a sunny day when the outside air temperature is 4°c. the room is estimated to lose heat at a rate of 120 mj/h. (i) determine the coefficient of performance (cop) of the heat pump (ii) determine the required power input to the heat pump

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.