A stoped out area with a volume of 20000 m3 is to be used as a receiver. It is to be charged to an absolute pressure of 1600 kPa during off shifts. The intention is to draw air from the receiver during the 4-hour drilling shift until the absolute pressure drops to 800 kPa. What is the rate at which the main air supply can be boosted during this period? Air temperature is 32°C, gas constant for air R=287 J/kgK.