The minimum fresh air requirement of a residential building is specified to be 0.35 air change per hour. That is, 35 percent of the entire air contained in a residence should be replaced by fresh outdoor air every hour. If the ventilation requirement of a 3.0 m high, 200 m^2 residence is to be met entirely by a fan, determine a) the flow capacity in L/min of the fan that needs to be installed, b) the diameter of the duct if the air velocity is not to exceed 4 m/s.