Compressors on this page are rated roughly 75 to 84 CFM. The piston option is the 20 HP Champion R series two stage simplex at 77.8 CFM, on a 120 gallon horizontal tank or base mounted. Rotary screw options are the Chicago Pneumatic QRS20 at 82 CFM, the Atlas Copco G15L 20 HP at 78 CFM, the Atlas Copco GA18 25 HP at 84 CFM and 175 PSI, the Quincy QGSV 25 HP variable speed at 83 CFM, and the Atlas Copco GA11 VSD+ 15 HP which turns down from 81 to 29 CFM as demand drops.

What 80 CFM supports

Figure on 15 to 25 stations of steady pneumatic tooling, a body shop with two or three booths, a cabinet shop running a wide belt sander and a CNC router, or a tire and lube shop with six to eight bays. A single 1/4 inch blast nozzle at 100 PSI takes most of an 80 CFM machine on its own.

Piston or rotary screw at 80 CFM

The 20 HP Champion R is the last size where a simplex piston still makes sense. It is a cast iron pump a local mechanic can rebuild, but it should not run more than about 60 to 70 percent of the time. If the shop draws near 80 CFM all shift, buy a screw. The fixed speed screws run continuously and hold pressure within a few PSI. The GA11 VSD+ and QGSV 25 are the picks when demand swings through the day; the drive slows the airend instead of blowing off unloaded.

Power and installation

A 20 HP motor draws about 27 amps at 460 volt or 54 amps at 230 volt; a 25 HP motor about 34 or 68 amps. Rotary screws want 36 inches of clearance on the cooling air side and a receiver of at least 120 gallons so the machine does not hunt between load and unload.

Dryer sizing

Pair an 80 CFM compressor with a 100 CFM refrigerated air dryer. Several screw variants here ship with the dryer built in; check the variant list before buying a separate one.

Related pages

• 70 CFM air compressors
• 90 CFM air compressors
• 20 to 50 HP rotary screw air compressors
• Shop all sizes by CFM