300 m3/min of air at 10°C dry bulb temperature and 90% relative humidity is to be heated and humidified to 35°C dry bulb temperature and 22.5°C wet bulb temperature. The required conditions are achieved by heating, humidifying and then again by heating. The relative humidity of the air coming out of the humidifier is 90%. Find
(i) the heating capacity of the first heater and the by-pass factor if the surface temperature of the coil is 40°C
(ii) the capacity of the humidifier in kg/hour
(iii) the heating capacity of the second heater and the coil surface temperature if the bypass factor is 0.5, and
(iv) the humidifying efficiency of air washer (humidifier).