Designing and planning an air compressor system
Designing an industrial compressed air system from scratch gives you the unique opportunity to optimize for efficiency, cost savings, and long-term reliability. This article will guide you through the essentials of designing a system that meets your current needs, and adapts to future ones.
Planning an efficient compressed air system
When designing an air compressor system, numerous parameters have to be taken into account and many decisions have to be made to meet the requirements of the operator, the specific compressed air application, and to achieve the lowest possible operating costs. The installation should also be designed to accommodate future expansion if this becomes necessary.
It is important to note that the machines themselves, as well as the planning and installation, only account for a small part of the total life cycle costs. The later operating costs, particularly energy consumption, make up the bulk of the total costs. For this reason, all planning should focus on maintenance-friendly and efficient technology, from the compressors and the pipework system to the compressed air dryers and filters. The type of compressed air technology that should be used, on the other hand, is dictated by the application or the processes that will require the compressed air.
Step 1: Define site conditions
To ensure efficient piping and system performance in large installations, it's best to place the compressed air plant where it allows easy routing of the distribution network. Ideally, it should be located close to auxiliary equipment like pumps, fans, or even near the boiler room. This setup makes service and maintenance faster and more accessible.
The chosen building should feature lifting equipment capable of handling the heaviest components of the compressor installation, typically the electric motor. Alternatively, access to a forklift truck can serve the purpose. It should also have sufficient floor space for the installation of an extra compressor for future expansion. In addition, clearance height must be sufficient to allow an electric motor or similar to be hoisted, should the need arise.
A floor drain or similar provisions must be in place to manage condensation from the compressor, aftercooler, air receiver, dryers, and other components. The floor drain must be implemented in compliance with municipal legislation.
Step 2: Estimate air demand
Understanding the flow and pressure requirements for your facility is key when choosing an air compressor. Pressure and flow are common terms used when discussing compressed air systems.
- Pressure: Refers to the amount of force needed to perform a certain amount of work at any given point in time. Can be measured in pounds per square inch (psi) or bar (metric measure of pressure).
- Flow: Determines how quickly and efficiently a compressor completes a task, depending on the required duration. Is measured in cubic feet per minute (cfm), liters per second (l/s), or cubic meters per hour (m³/h) depending on your location.
To calculate your total compressed air requirement, list all compressed air consumers, (tools, machines, systems) along with their pressure and flow requirements. Use manufacturer data or estimated values. When possible, benchmark against similar facilities.
After adding individual needs together, apply a "simultaneity factor" to account for non-continuous operation. Be sure to include a margin for leaks, wear, and future expansion.
Different tools and applications require specific flow and pressure levels. Here are typical air requirements for common tools and industrial applications.
| Applications | Flow & Pressure (US) | Flow & Pressure (Metric) | Air Tools | Flow & Pressure (US) | Flow & Pressure (Metric) |
|---|---|---|---|---|---|
| Home Use | 1–2 CFM 70–90 PSI |
0.47–0.94 L/s 4.8–6.2 bar |
Airbrush | 0.5–1.5 CFM 20–30 PSI |
0.24–0.71 L/s 1.4–2.1 bar |
| Spray Gun | 4–8 CFM 30–50 PSI |
1.89–3.78 L/s 2.1–3.4 bar |
Nail Gun | 1–2 CFM 70–90 PSI |
0.47–0.94 L/s 4.8–6.2 bar |
| Sandblasting | 6–25 CFM 70–90 PSI |
2.83–11.8 L/s 4.8–6.2 bar |
Tire Inflator | 2–3 CFM 100–150 PSI |
0.94–1.42 L/s 6.9–10.3 bar |
| Various Power Tools | 3–10 CFM 90–120 PSI |
1.42–4.72 L/s 6.2–8.3 bar |
Impact Wrench | 3–5 CFM 90–100 PSI |
1.42–2.36 L/s 6.2–6.9 bar |
| HVAC Systems | 6–12 CFM 80–100 PSI |
2.83–5.66 L/s 5.5–6.9 bar |
Air Ratchet | 3–5 CFM 90–100 PSI |
1.42–2.36 L/s 6.2–6.9 bar |
| Refrigeration | 3–5 CFM 60–80 PSI |
1.42–2.36 L/s 4.1–5.5 bar |
Hammer Drill | 3–6 CFM 90–120 PSI |
1.42–2.83 L/s 6.2–8.3 bar |
| Automotive Assembly | 8–15 CFM 90–120 PSI |
3.78–7.08 L/s 6.2–8.3 bar |
Paint Sprayer | 6–7 CFM 30–50 PSI |
2.83–3.30 L/s 2.1–3.4 bar |
| Food & Beverage Packaging | 4–10 CFM 70–90 PSI |
1.89–4.72 L/s 4.8–6.2 bar |
Grinder | 5–8 CFM 90–120 PSI |
2.36–3.78 L/s 6.2–8.3 bar |
Optimize compressed air performance in complex environments
In complex environments with multiple applications and tools relying on compressed air, a dedicated room for the compressed air system ensures optimal performance and energy efficiency. By balancing air delivery across various demands, it prevents pressure drops, reduces waste, and adapts to shifting usage patterns in real time.
Step 3: Size the compressor
Selecting the right compressor begins with understanding your airflow needs. The flow is measured in CFM and tells you how much air your equipment requires to run efficiently. Since each tool or machine may need a different amount of airflow, it's important to choose a compressor that matches your specific applications.
Next, consider the required operating pressure, measured in PSI. Tasks like pneumatic tooling or spray painting often demand different pressure levels to work effectively. Don’t forget to account for possible pressure drops caused by filters, dryers, or long piping runs.
It’s also important to look at the overall application. Some uses may require higher air quality or more consistent pressure. Lastly, consider the compressor’s power, measured in horsepower or kilowatts. While power matters, it should support the airflow and pressure needs you’ve already defined, not drive the selection on its own.
Step 4: Select accessories & controls
The right equipment configuration depends entirely on your application. Some operations may require oil-free compressors to protect sensitive processes, while others can rely on oil-injected models.
Choosing between fixed speed and variable speed drive (vsd) compressors depends on several factors, including how stable or fluctuating your air demand is. VSD compressors are typically more efficient in applications with varying demand, while fixed speed units may suit operations with a constant load. Additionally, the required level of air purity should guide your selection of air filters and drying systems.
Efficient air dryers, high-performance filters, and integrated setups can improve overall system reliability, reduce maintenance, and save space, especially when tailored to your pressure and flow requirements.
Downtime can also be avoided by using a compressor control system. A central control system can manage multiple compressors. It balances operating hours across units to reduce wear and tear, streamlines maintenance tasks, and seamlessly substitutes any failed or offline unit, ensuring consistent pressure and uninterrupted production.
Pro Tip: Minimizing total life cycle costs
A lower purchase cost might seem like a great deal, but it can lead to higher expenses in the long run. Spending a bit more upfront often pays off, especially when the compressor is more efficient and easier to maintain.
Achieving reduced energy consumption is key, as energy use can account for up to 80% of a compressor’s total lifetime cost.
That’s why it’s important to choose technology and equipment designed to save energy. From Variable Speed Drive (VSD) compressors to heat recovery systems, selecting the right components from the start leads to lower operating costs and a reduced environmental footprint.
Related articles
Planning a compressed air system can bring many question during the process. If you want to learn more about other related topics, check the following related articles.
