I have a 4 story building that has a closed loop water system in which it is used to cool the shell and tube condensers on about 20 refrigeration walk-in condensers. The closed loop cooling tower and the water pump are located on the roof. The make up water was shut off for an extended period of time and there was a leak at the pressure relief valve which drastically lowered the closed loop pressure. Once I found the problem I opened the fill valve and made sure the auto bleed valves were all working. However my question is this. What is the fastest way to get the air out of the system? Should I shut the pump off and let the system fill while bleeding from the highest point or just let the auto bleeds take care of the air. There seems to be alot of air in the system from the sounds of it. Any proven articles would be greatly appreciated.