A cabinet dryer is being used to dry a food product from 68% moisture content (wet basic) to 5.5% moisture content (wet basic). The drying air enters the system at 54oC and 10%RH and leaves at 30oC and 70%RH. The product temperature is 25oC throughout drying. Compute the quality of air required for drying on the basis of 1 kg of product solids.