100 PSI air compressors: more CFM from the same horsepower

A 100 PSI rated compressor is the right buy when the tools and processes on the line run at 90 PSI or less, which covers most impact wrenches, sanders, grinders, blow guns and sandblast pots. Compressing to 100 PSI instead of 150 or 175 takes less work per cubic foot, so the same motor delivers more air. The Atlas Copco G15L on this page makes 93 CFM at 100 PSI and 78 CFM at 150 PSI from the same 20 HP motor, and the Chicago Pneumatic CPBG, CPCG and CPI gear drive rotary screws show the same spread across their 100 to 175 PSI builds. If your plant setpoint is 100 to 110 PSI, the 100 PSI build is cheaper to run every hour it is on.

What is on this page

Stationary rotary screws from Chicago Pneumatic (CPBG 20 to 35 HP, CPCG 40 to 60 HP, CPI 75 to 100 HP) and Atlas Copco (GA15 to GA30 and G15L to G22, 20 to 40 HP) in their 100 PSI configurations. Atlas Copco CR cast iron piston units rated 100 PSI, including the steel tank simplex, the industrial series and the Professional and Industrial duplex packages. Atlas Copco SF8-22 oil free scroll at 100 PSI for labs, dental and food work. Jobsite machines rated 100 PSI: the Chicago Pneumatic CPS 175-100 towable, the CPS 185 KDU utility mount and the Atlas Copco X-Air 185-100 cold weather towable. Sandblasting and pavement breaking are 100 PSI jobs, which is why most 185 CFM towables are built to it.

Sizing notes

Pressure does not do work by itself. The tool needs its rated pressure at the inlet after the drop through the dryer, filter, hose and coupler, so plan on 10 to 15 PSI of loss on a typical shop system. A 100 PSI machine comfortably feeds 90 PSI tools, and a 110 PSI cut-out leaves margin for the unloader to cycle. If a few tools need 120 PSI or more, a separate small two stage unit for that bay is usually cheaper than running the whole plant at higher pressure. Size the receiver at 3 to 5 gallons per CFM for a piston unit and at least 1 gallon per CFM for a fixed speed rotary screw, and match the refrigerated air dryer to the compressor CFM at its rated pressure.

Related pages

• 125 PSI air compressors
• Towable air compressors
• Rotary screw air compressors
• Shop by PSI and Shop by CFM