ForConstructionPros.com

Whether it's a small utility model, a mid-sized towable version or a large mountable unit, it's important to correctly size a compressor to the application.

"When you undersize a compressor, it takes more time to finish a task. You may have workers sitting idle waiting for enough air to be generated," says Peter Grimmer, GrimmerSchmidt. "When you oversize a compressor, you can also run into efficiency issues - you're simply spending more than you need to from an initial investment standpoint. You will also burn more fuel and you will need larger equipment to move it from jobsite to jobsite."

What are your cfm requirements?
A compressor is usually sized according to the amount of air it can compress to 100 lbs. per square inch (psi) in one minute. This is denoted in cubic feet per minute (cfm), says Chance Chartters, sales manager, Mobilair, Kaeser Compressors.

However, keep in mind that altitude can affect cfm ratings. "The higher the altitude, the thinner the air and the less cfm you can generate," Grimmer explains. "Manufacturers have charts available that will outline cfm ratings at higher altitudes. Refer to them if you're working above 8,000 ft."

The first step in determining the size of compressor needed is to establish the cfm requirements of the tools you intend to use. This information is typically labeled on the tool, or can be found in the owner's manual. As a rule of thumb, a paving breaker's weight usually corresponds to the amount of cfm it requires. For example, a 90-lb. breaker requires approximately 90 cfm, a 60-lb. breaker requires approximately 60 cfm, etc.