A tow behind air compressor is sized in cubic feet per minute at a working pressure, and the 185 cfm diesel unit is the one most yards keep in numbers. It will run two 60 pound breakers, or one large tool with margin to spare. Below it sit 90 cfm units for a single tool; above it 375 and 750 cfm machines for drilling and blasting.
Add up the tools, then add margin
Every air tool has a consumption figure at 90 psi. Total the tools that will run at the same time and add roughly a fifth for hose losses and worn tools. Undersizing shows up as a breaker that slows to a crawl the moment the second one starts, and that costs more in labour than the bigger machine costs in rent.
Hose, oiler and fittings are separate lines
The compressor arrives with a coupler and little else at most yards. Air hose is rented by the length, usually in 50 ft sections, along with the whips, the inline oiler and the tool itself. Confirm what is on the ticket before the truck leaves, because a breaker with no hose is a day lost.
Towing it and standing it
A 185 cfm unit on a single axle is inside what a half ton truck will pull, with a 2 inch ball, working lights and safety chains. On site it has to stand level, clear of the work, with the exhaust away from where people are breathing. Yards will deliver instead, and in town that is often simpler.
Fuel is on your ticket
Diesel machines go out full and come back full, or the yard refuels at a rate that is never the cheap rate. A 185 running steadily gets through a useful amount in a shift, so plan a can and a funnel on site. Idling burns it too, so shut the machine down over lunch.
Questions people ask about tow behind air compressor
What size compressor runs a jackhammer?
One 60 pound class breaker is comfortable on a 90 cfm machine and two are comfortable on a 185. Larger paving breakers, or several tools at once, push you to a 375. If in doubt, give the yard the tool model and the number of them and let them size it.
Can I rent the breaker with the compressor?
Yes, and it is normally one ticket: machine, hose, oiler, breaker, steels and points. Take a spare moil point if the concrete is hard, because a blunt one turns a morning into a full day.
Are there electric alternatives?
Tow behind machines are diesel almost without exception, because the power involved is far beyond a site outlet. Electric compressors exist at the small end for indoor finishing work, and they are a different product on a different shelf at the counter.
Does it need a plate to be towed?
Trailer mounted compressors carry a VIN and are titled in most states, and the yard's unit will be registered and insured for the road. Your side of it is the tow vehicle, the hitch rating and the lights working before you pull out of the gate.