Air compressor sizes range from stationary shop compressors to compact, vehicle-mounted units. Air compressors for mobile tire changing trucks serve important functions, powering tire changing equipment and filling tires. However, these systems must be properly designed to ensure safety and reliability. Onboard air systems consist of many separate components—including the compressor, filter, tank, and more—that must function well individually and together.
At Oasis Manufacturing, we develop DC-powered, vehicle-mounted air compressors and accessories, including tire truck air compressors. Here, you can learn more about the components that go into our onboard air systems and why our products outperform others on the market.
Components and Considerations
Compressors are the heart of any onboard air system. DC-powered compressors are typically reciprocating, which means that they rely on pistons to function. There are two types of reciprocating compressors: oil-lubricated and oil-less. Oil-lubricated compressors are similar to small engines in their design, featuring crankshafts, rods, pistons, and wrist pins. With proper maintenance, they deliver a long service life and high-performance capabilities.
Oil-less compressors are less expensive and easy to rebuild. However, because they run at faster RPMs, their internal components wear out more quickly. They often have a shorter service life than oil-lubricated devices and significantly lower compressed air output.
Specifications
Factors such as flow rate, max pressure, duty cycle, and current draw all have a major impact on system performance. Understanding these terms is crucial for selecting the best system for your needs.
- Flow rate (CFM): How much air is pumped per minute at a specific pressure.
- Max pressure (PSI): The maximum pressure the compressor can create.
- Duty cycle: Describes operational minutes per hour at a specific pressure and temperature.
- Current draw (amps): The amount of current the compressor uses.
Tanks
Tanks are beneficial for certain compressed air needs, like powering air tools and air suspension systems. While air compressors with tanks can run more powerful air tools and require less frequent compressor starts, tanks do not reduce the compressor’s workload. Tanks also take up space, so they can be challenging to fit into constrained-space environments.
Additional Components
In addition to the compressor itself, onboard air systems require numerous other components, including:
- Air line filters: Remove particles from the air line.
- Check valves: Prevent air from flowing back into the compressor.
- Coalescing filters: Remove oil, water, and particles from the air line.
- Couplers: Quick connect/disconnect.
- Coil hoses: Flexible air tool power cords.
- Drain valves: Drain moisture and oil from the tank.
- DOT air brake hose: Flexible, for easy installation.
- Fittings: Connect components.
- Hose: Connects the compressor to the tank. Made from braided stainless steel and lined with Teflon for high-temperature resistance.
- Manifolds: Multiple output ports.
- Regulator: Maintains constant output pressure.
- Safety valve: Vents pressure if the pressure switch fails.
- Tank gauge: Shows tank pressure.
- Unloader valve: Vents pressure for easier compressor restarts.
Electrical System
Onboard air compressors have several electrical system requirements, which are especially crucial for high-power compressors. The type of battery used and its proximity to the compressor play an important role in overall system performance. Direct current is inefficient for distributing power, as high current levels with long wire runs result in large voltage drops. The power is wasted as heat in the cable. This is why mounting the battery as close as possible to the compressor is important. If this is impractical, use a cable with as large a diameter as possible to minimize the power loss.
In general, Odyssey AGM (absorbed glass mat) batteries are suitable for most needs. The Delco Voyager deep-cycle battery is another reliable option. Battery isolators are also important system components for protecting the vehicle’s battery. Battery isolators are the safest way to connect the auxiliary battery to the vehicle charging system, allowing both batteries to charge from a single alternator. If one battery becomes deep-discharged, the isolator protects the other battery.
Why Choose Oasis Manufacturing for Your Mobile Service Station DC Air Compressor?
DC air compressors from Oasis Manufacturing deliver more efficient and powerful continuous-duty performance. With limited vehicle space, eliminating the need for tanks and extra compressors is a priority. Our compact compressors are not only simple to install but can even improve the performance of your air tools.
Different power sources and charging systems affect continuous run time capabilities. For example, a 2.5 hp, 100% duty compressor at 12VDC with batteries in new condition delivers significantly different continuous runtime capabilities depending on the power source used:
- Group 27 size Delco Voyager deep cycle battery alone, engine off: 8 minutes estimated continuous run time
- Odyssey 2150 battery alone, engine off: 25 minutes estimated continuous run time
- Group 27 size Delco Voyager, 50 amps charging: 15 minutes estimated continuous run time
- Group 27 size Delco Voyager, 100 amps charging: 30 minutes estimated continuous run time
- Group 27 size Delco Voyager, 160 amps charging: Approximately 10 hours estimated continuous run time
It should be noted that most aftermarket alternators may not deliver their full rated output, especially when idling. A throttle positioning device may be necessary to guarantee sufficient charging.
About Oasis Manufacturing
Oasis Manufacturing began in 1996 as a company serving off-road enthusiasts needing a solution that could quickly deflate and inflate their tires. With a focus on innovation and exceptional customer service, today we provide high-quality DC air compressors, including mobile air compressors for tire changers. Our high-performance DC compressors are designed to power demanding air tools without a tank. Request a quote today to experience our industry-leading solutions and personalized customer care.