This guide is offered as an introduction to compressed air equipment that sometimes is needed to supplement or substitute for fixed utility sources.
What are Air Compressors?
Air compressors are trailered to work sites for a variety of industrial or construction applications ranging from powering impact wrenches in the assembly of a steel structure to triggering air hammers in demolition work. For purposes of this guide, we are talking about fully mobile units mounted on tow-behind trailers.
Manufacturers of compressor units are numerous and established. Global names like Atlas Copco, Sullair, and Kaeser immediately come to mind. While start-up brands and niche manufacturers always are worth a look, decades of manufacturing excellence generally are proof of quality. When in the market for tow-behind power or compressor units, remember that reliable performance should trump price when emergency work or uninterrupted production is the goal.
Heed Service Agreements
Almost as important as reputation are manufacturer warranties and dealership support. Compressors that fail or inexplicably shut down can bring havoc to a public event or disrupt an emergency response. When machines fail — anything mechanical occasionally does — the written pledge of a dealership or manufacturer to respond immediately with a replacement unit is a value that’s hard to put a price tag on.
Where to Buy
Buyers have several ways to acquire one of these towable machines. Some manufacturers offer direct factory sales, which eliminates costs associated with purchasing through a dealership. On the other hand, the proximity of a dealership can be important for product support. Second-hand air compressors can be found at brick-and-mortar stores as well as online. Auctions are yet another source for second-hand equipment, with some auction houses specializing in government surplus units. Caution: Online buyers should pay attention to stipulated limits on the condition of equipment.Back to top ↑
Many reputable rental companies, national and local, carry these portable pieces of equipment in their inventory, usually stocking market-leading brands. Two general rules of thumb:
Shop Size and Capacity
Manufacturers offer auxiliary support equipment in a wide range of outputs. While you know your needs better than anyone, an experienced rental or leasing agent can match your need to a particular piece of equipment. While you may not know the cubic feet per minute of air flow you need in a compressor, the experts should be able to tell you.
Understand the Agreement
The terms of service in a rental document protect you and the rental company. On the company side, the renter is accountable for any abuse or neglect of a rented machine and for returning the machine to the store by a stipulated date. Essentially, the renter must care for the machine so that it is returned promptly and in the same condition as when it left the lot. For the renter, the agreement ensures that the piece of equipment will function as promised and that, if it doesn’t, a replacement machine will be provided at no additional cost. Read the fine print for peace of mind.Back to top ↑
In a global market, the price for an auxiliary power unit varies by region. The more widely you explore the market, the broader your options are apt to be. Following are some advertised samples of pricing:
New Towable Air Compressor
Used Towable Air Compressor
Second-hand equipment is a good investment if attention is paid to condition and to a particular model’s track record of performance. Some shine might be gone from the paint, but the underlying mechanics can have years of dependable service in them. Following is a sampling of advertised prices:
Rental Or Leasing Costs
Rental markets vary so widely between rural and urban regions and different economic areas that price generalizations are hardly conclusive. Suggested rental/lease rates are just that — suggestions. With that caveat, following are some ballpark rental prices:
Some Purchase Options
Buying a towable auxiliary power unit can be a substantial investment. When a buyer is a new contractor or a property owner, funding the purchase can be problematic. Equipment dealers and second-hand stores understand this and offer a variety of ways for buyers to finance the needed power units. Some dealers offer lease agreements with an option to buy, sometimes at rates lower than traditional financing. Others charge no interest on a credit card purchase if the full amount is paid off in 18 months. Supply and demand ultimately determine financing costs.Back to top ↑
Rotary screw or piston
Most commercial towable air compressors employ rotary screws to squeeze or pressurize air. The pressure is produced immediately and constantly. Older piston compressors pump air into tanks that are then tapped for use. The latter work for smaller tools, but larger draws on the air can deplete the tanks faster than they can be replenished.
Output from a compressor is measured in cubic feet per minute and pounds per square inch. The more critical of these is the cfm rate because it tells if a machine will produce sufficient flow to do the work. Determine how much flow your equipment needs to operate and buy or rent a compressor that produces that amount plus a little extra.
A rented compressor or a used one sometimes is victimized by the last work crew to use it. Hoses (and couplings) are most vulnerable to neglect or abuse, getting run over or abraded. Short lengths of hose joined with an excessive number of couplings can reduce psi and starve a tool on the working end. Check an engine for evidence of maintenance and care — and check the hoses, too.Back to top ↑
This Swedish company has been producing quality equipment for 146 years and is purported to be the world’s largest manufacturer of air compressors. Atlas Copco is the parent company of Chicago Pneumatic, another brand of auxiliary power. Click here to see Air Compressors currently for sale from Atlas Copco →
A German manufacturer dating from 1919, Kaeser built its first compressor in 1948 and its first rotary screw compressor 25 years later. In 1982, it introduced its Mobilair towable compressors. In 2002, the company opened a second Mobilair plant. Click here to see Air Compressors currently for sale from Kaeser →
A worldwide leader in air compressors, Sullair was founded more than a half century ago in Indiana and now has manufacturing centers in both the U.S. and China. In 2017, it was absorbed by Hitachi Group. Click here to see Air Compressors currently for sale from Sullair →Back to top ↑
Air Compressors are not acquired on a whim. Genuine need drives the purchase or rental of such equipment — emergencies, urgent maintenance work, and expansion of a work project into a 24/7 operation. The good news is that manufacturers have a full line of equipment for such time-sensitive situations, so a need can be met quickly.Back to top ↑