8.20 A building is heated and humidified using the sys- tem shown in Fig. 8.14. The building has a sensible- heat loss of 260 kW and a latent-heat loss of 29 kW. The building space is maintained at 20 C dry-bulb and 40 percent relative humidity. Outside air is at 3 C dry-bulb and 30 percent relative humidity. Forty-five percent of the mass flow rate of dry air supplied to the space is outside air. The supply air is at a dry-bulb temperature of 35 C. The air exit- ing the air washer is at 80 percent relative humidity. (a) Sketch and label all points and processes on a psychrometric chart. (b) Calculate the rate of heat addition to the moist air by the preheat coil. (c) Calculate the rate of moisture addition by the air washer. (d) Calculate the rate of heat addition to the moist air by the reheat coil.