=+3-22.

Air is humidified with the dry bulb temperature remaining constant. Wet steam is supplied for humidification at 20 psia (138 kPa). If the air is at 80 F (32 C) db, 60 F (16 C) wb, und set-

level pressure, what quality must the steam have

(a) to provide saturated air and

(b) to provide air at 70 percent relative humidity?