Collection: Towable Air Compressors

The smallest practical tow behind makes 185 CFM at 100 PSI, and that is the size that moves most. It runs two 60 pound breakers, a small blast pot, or a 3/4 inch air hammer with margin left over. Above it the common steps are 375, 750 and 900 CFM, and 100 PSI gives way to 150 and 200 PSI machines built for down the hole drilling.

These are diesel driven rotary screws on a trailer, not large versions of a shop compressor. They run 100 percent duty cycle, carry their own fuel, and never care about voltage drop at the end of a long cord.

Size by the tool, then size the hose

Add up the CFM of every tool running at once and add 20 to 30 percent. Then look at the hose, because that is where the pressure goes. Two hundred feet of 3/4 inch hose at 150 CFM gives up roughly 10 PSI, and a breaker that wants 90 PSI at the tool stops hitting hard at 75. Going up a hose size is cheaper than going up a compressor size.

A towable is the wrong answer indoors, anywhere near a building air intake, and anywhere the work is intermittent. An engine idling all day for twenty minutes of actual air burns fuel and service hours for nothing. For that pattern an electric shop unit with a long hose or a portable electric compressor costs far less to own.

Buying used, check air end hours and the aftercooler rather than engine hours alone. Service intervals run on the engine, but the air end and the separator element are the expensive failures. Confirm your tow vehicle's hitch rating and brake controller before delivery day, and match pneumatic tools to the CFM you actually have.