Top 10 Things To Consider When Designing An Air Compressor System

July 13, 2020

Designing an air compressor system for a mobile application is no easy task. There are numerous factors to consider and decisions to be made, and a lot of thought and time is required to build a properly functioning system. To help you get started, we’ve put together this top 10 list of things you need to consider when designing your next air compressor system.

1. Air Compressor Type

First, you need to determine what type of air compressor is best suited for your project. There are generally 3 types of air compressors to consider for mobile applications:

  1. Rotary screw
  2. Reciprocating
  3. Rotary vane

Each type of air compressor has its own advantages and disadvantages. In the past, reciprocating air compressors were the most popular due to the inexpensive upfront cost and prominence in the market. However, in recent years, rotary screw air compressors are becoming the preferred choice for mobile applications because they are small, powerful, and have minimal moving parts.

Read “3 Types of Air Compressors For Your Industrial Engine” to learn more about these popular air compressor types.

2. Power & Drive System

Next, you need to ensure that the power and torque available from your power source are up to the task of the compressor you’ve chosen. Choosing a source with too little power and torque will mean your compressor can’t run to its capacity (or at all), while over-spec’ing may result in increased fuel costs and an overpriced initial investment cost.

Check out “Power Requirements For Your Industrial Engine Powered Air Compressor” to learn more.

Once you’ve narrowed down your power source, you need to figure out which drive system you will use to connect with it. There are several options for driving an air compressor system, including:

  • Engine Mounted FEAD Belt Drive
  • Frame Mounted Belt Drive
  • Auxiliary Port Direct Drive
  • Flywheel Direct Drive
  • Flywheel Belt Drive
  • Hydraulic Drive
  • Electric Drive

Regardless of whether you choose a belt drive or a direct drive, drive alignment is a critical factor for your air compressor system.

With a belt drive, premature wear and noise are common signs of an alignment issue and in extreme cases it can result in the belt coming off the pulley.  Meanwhile, a direct drive system powered by misaligned shafts or couplers can result in noise, vibration, power loss, and premature wear of couplers, gears and bearings.

To find out more, read “Methods To Power Your Air Compressor With An Industrial Engine.”

3. Vibration Analysis

Vibration can be extraordinarily damaging to an air compressor system, as vibration causes damage and misaligned parts when it isn’t properly account for. Therefore, where and how you mount your compressor is dependent on the environment it will be working in.

Ask yourself these two questions to get started:

  1. Is the platform for the compressor subject to vibration, bouncing or intense movement?
  2. What is the recommended maximum vibration your components can reliably endure?

Once you understand how vibration is likely to impact your air compressor system, you can decide the best way to mount and secure your compressor. Anti-vibration pads are a common and inexpensive way to help minimize the amount of vibration in a system.

4. Temperature & Cooling

As you design your air compressor system, you’ll have to ensure your engine and other components are suitable to operate in the environment you’ll be working in. System temperature should be a concern within all aspects of your design, but it’s particularly important to look closely at these details:

Maximum Operating Temperature

Adding components to an engine generally requires the engine manufacturer to approve the application. Ensure you’re aware of the maximum operating temperature and work with the engine manufacturer to confirm your system passes an air-to-boil test for the desired operating temperature.

Hydraulic Oil

If you are using hydraulic power to drive your compressor, it is also important to ensure the hydraulic system can keep up with cooling. Ideally, you want to test the entire system with the hydraulic power running everything it can at once.

Compressor Cooling

Are you liquid cooling or air cooling your compressor? Are you tying into the engine coolant or adding an independent system?  Once you are up and running, ensure that the cooling can keep the compressor cool at its expected duty cycle.  Testing for the environment is also critical.  Is your equipment being used in extreme hot or cold temperatures?  If so, cooling requirements will be different than more temperate climates.

Air Temperature At Application End

Compressing air makes the air increase in temperature. Depending on the cooling of the compressor and the after treatment, the air being delivered to your tool or equipment can be very hot.  Ensure that the equipment can handle those temperatures.  If not, there are various accessories for reducing the temperature.

5. CFM

When you started designing your air compressor system, it’s likely you went through your requirements to determine the amount of air needed and chose a suitable air compressor based on the manufacturers specifications.

But once your system is up and running, you’ll have to ensure your particular air system still meets your needs. Changes in air temperature, altitude, power sources, hose size, and hose length all contribute to the overall system performance.

A simple orifice style test tool is the easiest way to determine your CFM, while more complicated tools are available that meet standards like ASME.  But even these tests have their limitations and the true capability of your system will be discovered when you run your equipment and tools like they’ll be used in the field.

6. Safety Systems

When designing your air compressor system, it is important to consider these features to keep your system and operators safe:

  • Automatic blow-down valves – These valves protect your compressor from starting against system back pressure and help ensure the system is depressurized and safe to carry out maintenance.
  • Cold climate protection – Cold climate heating packages keep air compressors running in freezing temperatures while protecting components from the cold weather.
  • Pressure relief – Protects your components from operating at above their designed pressure.
  • Temperature monitoring – If something has failed or isn’t working properly, quite often it shows up as a temperature problem. Temperature switches and sensors protect your system from damage and help keep the operators safe.

7. Control System

Another important factor in air compressor system design is the controls. From simple on/off switches to intelligent digital systems, air compressors are controlled by a variety of means.

Control systems work in conjunction with safety systems and other equipment found on your machine. When designing more complex control systems, consider how much complexity you need, and what functions you would like your operators to be able to perform.

For example, do you want to include error tracking? What about service reminders? Would you like live telemetry so you can monitor your equipment and schedule maintenance before a breakdown occurs?

Before you start to design your control system, take the time to consider what information, functions, and capabilities you would like included.

8. Ease of access for service items

Ongoing maintenance of your air compressor system is vital for its longevity and performance. When designing and installing components, some thought into the maintenance goes a long way.

The list below includes many of the wearing and serviceable parts you should have relatively easy access to:

  • Switches, sensors, and control systems
  • Oil level checking
  • Oil filters
  • Air filters
  • Coalescing filters
  • Moisture traps and drains
  • Belts or other wearable drive train items
  • Ball valves

Consider how accessible each of these parts will be to minimize the future maintenance time of your air compressor system. Smart design can save significant time and frustration down the line.

9. Accessory Products

In addition to the air compressor system itself, you should also consider accessory products.

Does your application require you to add on some sort of after treatment? Do you want or require an air receiver tank? If so, planning for the location and potential electrical power requirements for some of these accessories is important before you complete your design.

Below is a short list of some accessories to think about during your design:

10. Failure Modes And Effects Analysis

When designing a compressor system, performing a FMEA can be a great way to catch and rectify issues before they happen. According to the American Society for Quality, “Failure modes and effects analysis (FMEA) is a step-by-step approach for identifying all possible failures in a design, a manufacturing or assembly process, or a product or service.”

Taking each component, operation, or design and evaluating it against potential issues may highlight areas of weakness.  By designing these potential failures out of the system before manufacturing, your system should enjoy a longer lifespan and better performance.

VMAC’s OEM Solution

Designing a compressor system from scratch is a massive undertaking. In addition to the 10 things to consider from this article, you should ensure you have a well-planned design process, clearly defined performance goals, and an understanding of your environment.

VMAC’s OEM division has experience designing air compressor systems for mobile applications in numerous industries, including mining, railway, transportation, and heavy-duty machinery. If you are interested in adapting one of our air compressor systems for your application, visit our OEM Solutions page to get started.