Convenient compressors

As long as you don’t need to leave it on the jobsite, you can save time and money with an on-board unit.

By Amy Materson

Eliminate the need for a PTO with Miller’s EnPak, a truck-integrated unit with a variable speed rotary screw air compressor that pumps out 40 cfm at 100 psi and a maximum psi of 175, all with the truck turned off. EnPak also powers electrical tools and hydraulic cranes.

An on-board air compressor can deliver considerable advantages when compared with a towable unit – lower cost, less weight, an open hitch, reduced maintenance and insurance requirements and having on-demand air paired with your truck. Many units can handle a variety of jobs from hand-held pneumatic tools to severe tire applications.

Making a list, checking it twice

Before you begin to compile your list of must-haves, check to see what your vehicle can handle with respect to available space and power. There’s a wide range of capacities, and compensating for an on-board compressor can result in a reduction of both payload and space. Also, take a look at your timeframe for vehicle replacement. If you frequently trade in trucks, for instance, transferability could be an issue, since reinstalling a compressor may be more costly than moving a towable unit. If this isn’t a problem, an on-board unit can save you money not only on the front end, but in fuel costs as well. Once you’ve determined your truck’s capabilities, then you can decide what you actually need. Right-sizing is important – ensuring the compressor matches your needs will lower costs and boost productivity.

VMAC’s Predatair delivers up to 40 or 60 cfm in a compact unit, providing enough output to power a diverse range of applications, from 5-pound air guns to a 60-pound jackhammer.

Reciprocating, or piston pump, compressors deliver air power suitable for most smaller pneumatic tools such as air ratchets, and, if sufficient for your applications, will be an economical choice. With a reciprocating unit, however, you must wait for auxiliary air tanks to be filled, which can eat up time on the jobsite. If your air requirements are greater than a reciprocating unit can provide, a rotary screw air compressor provides more air power on demand. Make sure you don’t overwork the compressor by choosing a unit too small for your applications – cycling the unit too often means you’ll have to wait while the air tank is refilling, creating a significant inefficiency over time.

Most units are either air-only or a compressor/welder/generator unit. If you don’t need a combo unit, choosing a compressor that offers air only will reduce your fuel needs and extend your maintenance intervals. If you’d like the productivity a combo unit delivers, look for models that meet your specifications, yet still provide bonuses such as increased fuel efficiency, noise reduction capability and increased truck capacity. Consider accessories such as hose reels and hydralic coolers.

Air N Arc’s line of combination units are designed with a two-generator system – one produces high frequency DC weld output and the other produces AC power – enabling the end user to weld while running any AC system.

Units that promise simplified service should be near the top of your list. Easy access to filters and fluids is a basic requirement, but also look for models with maintenance countdown timers or service interval reminders, available from several manufacturers. Also, make sure you’re aware of the installation requirements. Simpler units offer single-point connections that can often be handled by the user, but units integrated into the truck’s systems must be installed by trained upfitters.

New and improved

There are a number of new entries into the on-board compressor market, and all include customer-driven requests such as electronic diagnostics, plug-and-play connections and on-demand systems. Miller’s newest unit, the EnPak, is a combination air compressor, generator and hydraulic pump for mechanics trucks that allows the operator to use all tools, including air-powered impact wrenches, with the truck turned off. Although the EnPak does not include a welder, it can power one. In addition to saving fuel and reducing wear and tear on the truck, the EnPak reduces both noise and exhaust emissions.

Iowa Mold Tooling took reduced service requirements into account when developing the CAS35WG, a combo unit that includes a hydraulically driven 35-cfm reciprocating air compressor, a 250-amp welder with 50-foot leads and a 5,000-watt generator. You can easily follow a preventive maintenance schedule with quick access to everything within the unit. Filling compressor oil, changing intake filters and checking connections is accomplished by removing a few bolts and lifting the top of the unit.

Jenny’s compressors are available in either single or two stage, and have 30- or 80-gallon air tanks. All models feature a heavy duty splash lubricated cast iron compressor pump and are belt driven with a large flywheel for improved cooling and easy start-up.

Vanair’s newest underdeck model, the V3, offers three power sources from a single PTO, eliminating the need for access to a second PTO opening on the transmission. Upgrades to existing models focus on convenience and cost control. Vanair’s V-Tec Total Electronic Control and Diagnostic System simplifies installation with OEM-specific plug-and-play connections, comprehensive monitoring, and a Dual Pressure option. Requested by utility customers, this option lets you increase psi with a switch, allowing you to pressure gas lines or blow out valve boxes, for example. The company also plans to introduce two new models, currently in the engineering and testing phase, for their Air N Arc product line in 2010.

Vanair has underdeck models with 60- to 250-cfm capacities, and pressures from 100 to 200 psi. Vanair’s Genair system offers two sources of power with choices of 125-, 160- or 185-cfm compressors combined with 7- or 11-kW generators.

VMAC’s customers also wanted service alerts, so they’ve implemented a service reminder notice on the digital controller for every system. VMAC has also teamed up with Cimline, providing a 70-cfm compressor for their Crack Sealer/Melter/Applicator. Additionally, VMAC is preparing to introduce a new prototype – their Advanced Underhood System. Set to debut at next year’s NTEA show, the unit will address fuel savings, transferability and environmental concerns, as well as service intervals, longevity and truck idling. EW

Light equipment marketplace

Reduce vehicle weight and save on service costs with IMT’s CAS35WG, a compact hydraulic compressor/welder/generator that takes up the same space as a rotary screw compressed air system unit. The unit includes a 35-cfm reciprocating air compressor, a 250-amp welder suitable for service welding and a 5,000-watt generator.

Most manufacturers offer a variety of online resources. Here are a few to check out:

Features a fuel savings calculator, a short demo video and sound level comparisons.

This site has a handy tool consumption chart, system specifications and a FAQ file.

Application lists, demo videos and downloadable product manuals.

Features buying guidelines and a cfm chart.