How to design a compressed air system

Every compressed air system project is unique because compressed air needs vary according to its use, and there are many possible network configurations available. Optimal design of your compressed air system from the start of the project will ensure:

• The safety of those who are going to be using the compressed air
• Lower operating costs owing to enhanced system efficiency
• Optimal performance of pneumatic equipment and tools

So where do you start your project? How can you be sure you’ re not forgetting anything and that the compressed air system you’ re installing is truly adapted to the needs and requirements of your industry?

To help guide you through the process, we have compiled a list of six fundamental questions to ask before beginning a compressed air system project. Each question is accompanied by a practical exercise to help you carefully navigate through the process. Take the time to carefully plan each step of the process and, if necessary, don’t hesitate to enlist the help of an expert.

6 important questions to consider before starting your project

1. For what type of application will you be using the compressed air?

Each application requires different specifications (air volume, air quality). Before starting a project, you should determine what type of application you will be using your system for. You will have to take this into consideration when planning your project.

Practical exercise

Answer each of the following questions to the best of your knowledge. This will allow you to list all of your compressed air needs.

• What will be the applications?
• What pneumatic equipment or tools will be used?
• How often will it be used?
• What are the conditions of the work environment?

Examples of applications by industry:

2. What quantity of compressed air will be required?

Calculate the total air flow required to supply all the air equipment and tools you plan to use. The more workstations and equipment you have, the more air will be required. The diameter of the compressed air system will need to be large enough to supply enough air at the required pressure to all service points.

One of the biggest challenges with a compressed air system is ensuring that enough air is delivered to all the service points.

2-part practical exercise

Part 1 – Listing of requirements and necessary flow rates

Answer each of the following questions to the best of your knowledge. For each application of compressed air, be sure to list the required flow rate (SCFM). If necessary, refer to the table below “Examples of air consumption by tool type.”

• What are the needs for compressed air?
• How many pneumatic equipment and tools will be used?
• What volume of air (SCFM) does the pneumatic equipment and tools that will be used need to operate?
• What is the required frequency of use (daily vs. occasional)?
• What will be the duration of use (continuous vs. fixed periods)?

Examples of air consumption by tool type(indicative data according to continuous use)

SANDERS	FLOW SCFM
SANDER	9.6
4-1/2′ angle grinder	18.4
10 mm belt sander	18.9
7′ angle sander	29.6
NAILERS/STAPLERS
18 gage nailer/stapler	2.5
22-18 gauge stapler	3.5
Finishing nailer	3.5
Roofing nailer	6.0
Framing nailer	11.0
IMPACT TOOLS
Miniature 1/4′ ratchet	12.5
1/4′ impact gun	14.0
3/8′ ratchet	19.2
Zip gun	21.9
1/2′ impact gun	28.6
3/4′ impact gun	34.7
1′ impact gun	87.5
POLISHING TOOLS
Orbital polisher	16.6
Oscillating sander	23.0
DRILLS
3/8′ air drill	17.3
3/8′ reversible air drill	23.8
1/2' reversible air drill	26.4
OTHER TOOLS
Riveter	4.0
Grease gun	8.0
Caulking gun	0.1
HVLP paint gun	9.5
Screw driver	9.6
Gravity fed sand blaster	12.0

Part 2 – Calculating total flow requirements

Then add up all the air requirements for your pneumatic equipment and tools. This will give you an accurate estimate of the total flow rate required (SCFM) to operate your equipment simultaneously. This data will be useful for the next step.

3. Where are your pneumatic tools and equipment located?

Make sure you are familiar with the layout and workflow location of your plant or shop. This will have a significant influence on the type of configuration you choose. Consider the location of the compressor, the distance to be travelled and any drops (descents) required. The total length of the compressed air system in linear feet will determine the required pipe size and the preferred network configuration.

3-part practical exercise

Part 1 – Enumeration and visualization of the configuration

Answer each of the following questions to the best of your knowledge. This will enable you to visualize every element of your compressed air system.  

• How is the plant layout configured?
• What are the workstation locations and layouts (tools and equipment)?
• Where will the compressor be located?
• How far does the compressed air system need to go (total distance/size of the shop)?
• How many compressed air descents will be required?

Part 2 – Sketch of the installations

Now, take a sheet of paper and draw a sketch of your plant or workshop, identifying each compressor and workstation. Among other things, this will allow you to determine the most suitable configuration for your layout, the next element to consider. 

Examples of workstation layouts:

Part   3 – Definition of the required pipe  diameter

Based on the total air flow defined in question 2 - “What quantity of compressed air will be required?,” the length of the compressed air system you have determined by calculating the total distance and dimensions of your network, and the configuration you have just sketched out on your design by arranging the workstations (linear or in several different locations) you are now able to determine the required pipe diameter. Use the table below to guide you.

Guide to determine the pipe diameter (mm) required for a compressed air system

Data based on a closed loop network. The total airflow is the sum of each requirement of all pneumatic tools and equipment used on the network.

4. Will you be running a closed loop or a linear network?

The optimal configuration of the compressed air system is determined by the layout of the plant or shop. Refer to the practical exercise in question 3 - “Where are your pneumatic tools and equipment located” to determine what applies to your situation. Keep in mind that your goal is to achieve a balance between the air volume demand (flow rate measured in SCFM) and the required pressure (in PSI). This step will enable you to determine the diameter of the main network.

2 configuration options

Closed loop network

Closed loop networks are considered to be the most efficient configuration. They facilitate uniform pressure between all compressed air delivery points. Prioritize this type of configuration if your layout will accommodate it.

In a closed loop system, air flows through several lines at once. Pressure and flow remain balanced throughout the system. Air from two directions is supplied to each descent.

Linear network

When a closed loop configuration is not possible, choose a linear network. To supply the compressed air system in both directions, ideally the compressor should be located in the centre of the network (from the compressor to the furthest point of use).  You could also have more than one compressor.

In a linear system, air from one direction only is fed to each descent. This can lead to pressure drops at the end of the system if the system is very long. This is why the compressor should be located in the centre of the system.

Practical exercise

Based on the previous practical exercises, answer each of the following questions to the best of your knowledge.

• Which network configuration is most appropriate for the layout?
• Do you have to plan for future needs (expansions)?

5. Are there any air quality requirements that must be met?

The presence of water and contaminants causes pneumatic equipment failure and promotes bacterial growth in the compressed air piping system. Some applications or processes require very high air quality standards. This is the case for industries where compressed air may come into contact with food (food processing, pharmaceutical, nutraceutical, etc.).

One of the biggest challenges of using a compressed air system is to eliminate all water and contaminants.

ISO standard

The International Organization for Standardization (ISO) has established the 8573 air quality standard to assist in the selection, design and measurement of air handling components. Refer to this standard to see what applies to your industry.

Level 1	Level 2	Level 3	Level 4	Level 5
Compressed air without specification	General shop air: air tools (sand blasting, grinding)	Air instrument Spray painting Powder coating Packing machines	Food industry Pharmaceutical and chemical industries Laboratories	Food industry (breweries, dairies) Pharmaceutical and chemical industries Laboratories
ISO 8573.1 Class 5.6.5	ISO 8573.1 Class 3.6.4	ISO 8573.1 Class 1.5.3	ISO 8573.1 Class 1.4.1	ISO 8573.1 Class 1.1.1

To learn more about the compressed air treatment options and air quality levels established by ISO 8573.1:2010, see the article 5 solutions to remove and treat condensates.

Practical exercise

Answer each of the following questions to the best of your knowledge. This will allow you to properly assess your air quality needs and ensure that your compressed air system will function properly and last for years to come.

• What air quality is required for each application or industry (some applications may require local air treatment such as an FRL unit or desiccant air dryer)?
• Do air requirements vary from one tool or piece of equipment to another (plan for filters, regulators and lubricators at different application points)?
• What type of piping material should be used?

To ensure that the compressed air is clean and dry, choose materials that will not corrode or deteriorate. They allow air to flow freely without friction. For more information, consult the article 5 reasons to choose an aluminum compressed air pipe.

6. Who will perform the installation?

Although it may seem trivial, this last decision will determine how well your compressed air system will perform. Choose a qualified installer who follows all installations and safety regulations. Some systems are very simple to install, but it is essential that the installation be performed to the highest standards. No matter what stage of design your compressed air system is in, don’t hesitate to call on one of our consultants to help you choose the right components for your system or simply for advice on its installation.

Practical exercise

Answer each of the following questions to the best of your knowledge.

• Who will install the network?
• Will the installation be done by a specialist?

Did you know that installing an aluminum system comes with several advantages? The pipes are lightweight, and the self-locking compression fittings are easy to install. Installation is 4 times faster than the conventional method of tapping the pipes. As a result, you will enjoy a reduction in installation costs.

Lastly, remember that each compressed air piping system comes with its own unique features. Be sure to read the design and installation guides that come with the system you have chosen to use for your compressed air project.

For more detailed information on the steps to follow when designing a compressed air system, we invite you to consult our white paper Practical guide to planning a compressed air piping system.