A winter air conditioning system supplying air to a space at the rate of 2 kgs-1 has a heater and a steam humidifier as the processing units. The total heat loss from the space is 28 kW and the SHR is...

A winter air conditioning system supplying air to a space at the rate of 2 kgs-1 has a heater and a steam humidifier as the processing units. The total heat loss from the space is 28 kW and the SHR is 0.6. The space is maintained at 21°C db-temperature and 14.5°C wb-temperature. Before entering the heater, 40% by mass of the return air is exhausted and replaced with an equal quantity of outdoor air at 7°C and 10% relative humidity. The air enters the humidifier where saturated steam at 120°C is sprayed into the air stream. The pressure is constant at 101.3 kPa (a) Draw a schematic diagram of the system. (b) Calculate (i) the rate of heat input by the heater, and (ii) the rate of moisture addition by the humidifier.