# Political Science homework help

You are designing a ventilation system for a poultry barn that has 8000 laying hens (seeschematic below). Air enters the evaporative cooling pad at temperature of 35 C and arelative humidity of 30% and is evaporatively cooled to a relative humidity of 90%. Thisair is passed through a barn that has wall/roof heat transfer (into the building) of 60,000kJ h-1 and equipment heat transfer (into the building) of 10,000 kJ h-1. The enthalpy ofreaction corresponding to the hens metabolism rate is – 36 kJ h-1 bird-1. Approximatelyone-third of the enthalpy of reaction is used to evaporate water from the hen (similar toperspiration for humans). You can assume that evaporation occurs at T=29 C. To avoid heat stress for the hens, the temperature of air existing building cannot exceed29 C. What is the required air flow rate in units of kgdry min-1? You will need to use thespecific heat capacity at constant pressure of air (cps = 1 kJ K-1 kg-1dry) to determine theair flow rate. What is the relatively humidity of the air exiting the building?