Collection: Piston Air Compressors Under 5 HP

The horsepower printed on a consumer compressor is often peak draw, not running horsepower. A unit advertised at 6.5 peak HP on a 15 amp circuit is doing roughly 1.5 running HP of work. Everything on this page is listed by running horsepower, 0.6 to 4 HP, so the numbers compare straight across.

Who buys in this range

Trim carpenters and framers running nail guns, mobile detailers, hobby woodshops, tire inflation at a service counter, and anyone who needs air on a standard 115 volt outlet. At 2 HP you're looking at 4 to 5 CFM. At 4 HP, 8 to 11 CFM. That runs a nailer, a blow gun, a small ratchet, or an HVLP touch-up gun. It will not keep up with a 1/2 inch impact or a sander, which pull 5 to 9 CFM continuously. If that's the work, skip to 5 to 7.5 HP.

Oil-free or oil-lubricated

Oil-free units are quieter, lighter and need no oil changes, and the California Air Tools machines here run in the 60 to 70 dBA range, which is conversation-level. The tradeoff is service life: oil-free pumps are generally rated for 3,000 hours or less, where an oil-lubricated cast iron pump will go 10,000 or more. For intermittent use the oil-free unit usually outlasts the owner's interest in it. For daily shop duty, buy the oil-lubricated pump. More on that split in cutting compressor noise.

Power and circuits

Up to 2 HP, these run on 115 volt and will usually share a 15 or 20 amp circuit, though a compressor on a shared circuit is the most common cause of nuisance breaker trips we hear about. From 3 HP up, plan on 230 volt single phase. Wire and breaker sizing covers what each size draws.

If you're working from a nameplate on an old machine and the units don't match, the unit converter puts bar, l/min and kW into PSI, CFM and HP. Other sizes are on Shop by Horsepower.