Compressors here deliver roughly 23 to 27 CFM. It is a crossover point in the catalog: 7.5 HP two stage piston compressors from ABAC, Champion and Atlas Copco sit next to 13 to 16 HP gasoline engine units for service trucks and the smallest rotary screw and scroll compressors. Which one fits depends on duty cycle and where it will run.

Piston, rotary screw or gas drive

A 7.5 HP piston unit is the low cost choice for a shop that runs tools intermittently. It should not run more than about 60 percent of the hour, so if the compressor never shuts off it is undersized or the wrong type. A 5 to 7.5 HP rotary screw at the same CFM costs more but is rated for 100 percent duty, runs quieter, and delivers cooler air. Gas drive units from ABAC and Chicago Pneumatic bring 22 to 27 CFM to a truck bed or a jobsite with no power.

What 25 CFM supports

Four to six service bays, a frame shop, a sandblast cabinet in steady use, or two painters in one booth. Tank size of 80 to 120 gallons is typical on the piston units; rotary screws are often base mounted and paired with a separate receiver tank.

Dryer sizing

Use a 30 to 35 CFM refrigerated dryer for a 25 CFM compressor. Rotary screw packages are often offered with the dryer integrated, which saves piping and floor space.

Related pages

• 20 CFM air compressors
• 30 CFM air compressors
• Gas engine air compressors
• Rotary screw air compressors