CFM is the most important factor in air compressors because it tells us the airflow, and you’ll know if it suits your job. That is why it is said the more the CFM, the better it is…
However, sometimes it happens (Occasionally) that you need extra CFM for the specific tools to make it smooth. For that purpose, you can increase it, but how to increase CFM on air compressor? There are a few more methods to increase the CFM, which you can see further in the article.
But, before we go straight to increasing CFM, you should know what CFM is in detail. The more you know, the better you do!
- 1 What is CFM?
- 2 How to Increase CFM on Air Compressor?
- 2.1 1. Decrease the Pressure
- 2.2 Consideration:
- 2.3 2. Connecting Different CFM Compressors
- 2.4 Consideration:
- 2.5 3. Adding Same CFM Compressor
- 2.6 4. Adding Air Tank Reciever
- 2.7 Consideration:
- 2.8 5. Increasing the size of the Pump and Motor
- 2.9 6. Give the compressor more time to Compress
- 3 Which Method Should I Choose?
- 4 What’s the Difference Between Continuous use and Intermittent Use?
- 5 In Case You Want to Know How to Decrease CFM on Air Compressor?
- 6 How to Figure Out the CFM level of an air compressor?
- 7 What’s the difference between CFM and SCFM?
- 8 What is the difference between PSI and CFM?
- 9 Air Compressor Tank Size Vs. CFM
- 10 What CFM Air Compressor Do I Need?
- 11 Conclusion
- 12 FAQs
What is CFM?
CFM is an abbreviation of cubic feet per minute. This measure is the possible air amount the compressor can produce. It indicates the flow rate. The air is used to pressure the tools you can attach to your compressor.
There are a lot of pneumatic tools: which require compressed air from the compressor to be able to work smoothly and efficiently. This process makes the work easier and quicker. The higher your compressor can produce air, the more powerful and efficient it will work!
How is CFM Calculated?
Mostly CFM is mentioned on the compressor, but manufacturers can misinterpret the actual flow rate. To calculate the flow rate, you can follow a few steps, and you will be able to calculate your CFM.
- Firstly divide your compressor’s tank capacity by the number of one cubic foot, which I 7.48. For example, you have 100 gallons divided 100/by 7.48 ( to get the tank’s volume).
- Switch on the compressor to calculate the load and unload cycle timing from pressure gauges.
- Release any pressure from the compressor
- Then, start rebuilding pressure, and record the time of the compressor starting and the time it stops. Also, record the PSI of the compressor from the pressure gauge.
- While measuring if your compressor is loading at 80PSI and unloads at 120PSI, then the difference is 40 PSI. You need to divide this 40 by 14.7, which will give you the ATM of the compressor.
- Now, take the CFM ( which we got after dividing: gallons) and multiply it by ATM ( you got after dividing the difference of PSI by 14.7). It will give you the actual CF your compressor took while filling your compressor ( load and unload timing measuring step).
- Now divide your CF by minutes: dividing CF ( you got in the last step) by the seconds it took to pump. Then simply multiply the results by 60 ( you got your CFM).
How to Increase CFM on Air Compressor?
1. Decrease the Pressure
When the air pressure builds up in the compressor afterward, it is forced out at a specific flow rate which is CFM. The power rating of the compressors is different, which is equal the product of Pressure and CFM.
You cannot increase the compressor’s power ( from a certain limit), but reducing the pressure by turning down the regulator can increase the CFM. So, Yeah, CFM is depend on set pressure. If your working pressure is less than 90 PSI, it can boost your CFM.
- It is excellent for continuous use. (for air tools)
- It is also great for occasional use.
- It is cost-effective
- The change in CFM will not be drastic like more than 20-25%
- Your compressor with less than 90 PSI working relies on them.
2. Connecting Different CFM Compressors
You can increase CFM by connecting two air compressors. The compressors will have different CFM, models, and brands. You make your compressor CFM 15 CFM by connecting 10 CFM and 5 CFM compressors. It will give you continuous airflow.
You can connect two compressors following these steps:
- Using a T-piece air fitting, connect the outlets of your receiver tank.
- Then, connect the air hose of your compressor to T-piece.
- Lastly, connect the air hose to the tool.
- It will be great for continuous use.
- Also, for occasional use.
- It is not cost-effective because you have to buy two compressors
- It can be cost-effective if your lend the second compressor to a friend.
- You will need adjustable pressure switches
- Check the duty cycle
3. Adding Same CFM Compressor
You can increase air compressor CFM by adding another compressor with the same brand, model, and CFM. This will help double our CFM. in addition to adding more CFM. It will also add more CFM at the pressure regulator outlet.
You connect both compressors using an airline or T-piece air fitting, then plug your tool in the fitting. Because of the same model, brand, and CFM, there will be problems in synchronizing.
- It is excellent for continuous use.
- Great for occasional use.
- It is not cost-effective ( as you have to buy two compressors)
- Always check the duty Cycle.
4. Adding Air Tank Reciever
You can add an air tank receiver to increase the air compressor’s CFM. The compressor will fill both tanks. It is helpful in double storage. The motor of the compressor will work double and allow more storage.
As you have double storage, you have more CFM to work on. It does not increase the CFM of the compressor but the CFM of the air compressor pump. This process allows more colling time.
- It might not be great for continuous use
- It has cooling time and is excellent for occasional use.
- It might be cost-effective because it only needs an additional tank.
- The size of the tank needs to be done correctly.
- Check the duty cycle.
5. Increasing the size of the Pump and Motor
To increase the compressor’s CFM, you can use another method: adding an additional compressor pump that provides more CFM and continues use. You cannot only increase the motor size but have to increase the pump size because all motors have a different pump. This will have an oversized motor and a small pump if you do.
- It is more cost-effective than buying an additional compressor
- Your compressor should be capable of changes. Ensure to research that before doing anything
6. Give the compressor more time to Compress
You can also increase your air compressor’s CFM by allowing your compressor to compressor air more than the time. Eventually, the compressor will keep the tank pressure up. This one is the easiest and cheap method.
Which Method Should I Choose?
Increasing CFM for Cyclical or Intermittent Air Tool Use
If you want to increase your compressor’s CFM occasionally, intermittently, or on a cyclical high demand for more CFM. The demand is not continuous, and the other options are not cost-effective. Then adding the additional air storage tank is a great option.
This will enable you to have more storage capacity and more CFM for the time you need more CFM. This is not like adding more CFM but more like having more capacity to store!!
Increasing CFM for Continuous Air Tool Use
In case you have a continuous demand for higher CFM and you need more CFM for work daily. Then in this situation, adding more storage capacity is not a great option. You should either add an extra compressor or buy a high-capacity CFM compressor. This is a good option because, in this, you do not need to worry about maintaining two compressors or worrying about connecting two compressors.
What’s the Difference Between Continuous use and Intermittent Use?
As its name says, continuous use is for regular and continuous use without any breaks. In compressors, it means that the compressors are capable of running continuously because it has enough CFM and PSI, with a great duty cycle. The duty cycle of the compressor must need to be considered.
Intermittent use: it is a user with some intervals and breaks. In compressors, it means that the compressor is incapable of working continuously and needs breaks or intervals, again and again, to let the compressor build up its pressure again and to help it cool down. For this purpose, you need to consider the compressor’s duty cycle.
Regardless of anything you need, your compressor might be designed for cyclical operation, which means it is designed for ait tools. The compressors have a period for operation; they need time to cool down, which is called their duty cycle.
The compressor’s duty cycle is mentioned in percentages: 50% means if compressors have a duration of time for working 30-40 minutes, then it needs the same time to cool down. It needs the same amount of time to cool down as it works.
In Case You Want to Know How to Decrease CFM on Air Compressor?
You cannot only increase the CFM of the compressor but can also decrease it. But how? This is simple. There is a regulator of CFM in the compressor. You just need to dial down the CFM regulator; the CFM decreases when you quick-fill your compressor.
There are a few cautions you must take while decreasing your compressor’s CFM: If you need low CFM frequently, then the best option is to buy a less CFM compressor because the sudden drop of CFM can cause improper tank filling, which causes tools to stop while they are still running.
You can also lower CFM by doing these:
- If you want to decrease the CFM, you can simply increase the pressure on your outlet. This happens when the pressure difference between outlet and tank pressure is almost the same.
- You can also decrease the CFM by decreasing the hose size of your compressor because it adds pressure drop to the compressor. This will decrease the available airflow.
How to Figure Out the CFM level of an air compressor?
We have in this article already mentioned the formula for calculating the CFM of the compressor. However, CFM is mentioned in the compressors manual and the specification. But if you want to know by yourself, you can follow those steps to find out. ( mentioned in how to calculate CFM).
What is a good CFM rating for an air compressor?
CFM rating of the compressors depends on how much work you need from them. For general, household or DIY use the compressors with 5-8 CFM or even less 2-5 CFM is enough. This CFM is great on 80-90 PSI.
However, it depends on your tools if you need CFM for professional use. It can be higher than 15-20 CFM or even more with more than 70-80 Gallons.
What’s the difference between CFM and SCFM?
These both are essentials in the compressors. They indicate the airflow of the compressor.
The SCFM: measure the (ideal) pressure conditions and temperature
The CFM: measure the flow rate (actual). CFM is a measurement of airflow ( basically volume measurement) in the compressor.
What is the difference between PSI and CFM?
What does CFM mean? It defines the ability of the compressor to do different tasks, either heavy-duty or small. It produces the air on which the duration of completion of any task depends. When the compressor has less CFM, it will need intervals to coll down and build u pressure again while completing any project.
PSI is the pounds per square inch which is the pressure. This defines the time duration of any task completion. The compressor needs the correct PSI to complete the process. Pressure deliver force to the tool (If your compressor delivers too much force, it can damage the tool, and less pressure won’t complete a task).
In compressors, both are important because they equally define the compressor’s ability to complete a task.
Air Compressor Tank Size Vs. CFM
The tank size of the compressor means it has more storage capacity. If your compressor has more storage capacity, it will have more air stored, which helps continue work for the user. Tank size also affects the CFM: the more the tank capacity increases the CFM of the compressor. But you should also consider the duty cycle of the compressor.
What CFM Air Compressor Do I Need?
CFM indicates the air flow rate, which means it tells the amount of air the compressor can produce at different PSI. Generally, the higher PSI gives more air which helps in providing more pressure to the tools and helps in quick working. This makes the tools efficient and more smooth.
The higher the CFM, the more it can handle pneumatic tools and provide continuous running. But in any case, if you do not have enough CFM and need it, then? How to increase cfm on air compressor?
You can simply temporarily increase the compressor’s cfm by adding more storage tanks to allow more capacity to build up pressure and already built-up air. You can also add another compressor with the old one by connecting both to double the CFM of the compressor.
How do I increase air compressor capacity?
- You can increase its capacity by adding more tanks received with the compressor
- Add another compressor with the same model, brand and CFM
- Double the size of the motor and pump
- Or simply buy a larger capacity compressor.
Does CFM go up with PSI?
No, the reduction in the PSI increases the CFM of the compressor. When PSI decreases, it increases the CFM of the compressor. Like at 90PSI, the CFM of the compressor is 5CFM, and at 50 PSI, the CFM is 6.
Is higher CFM better air compressor?
Yes, the higher CFM give more air to the pneumatic tools attached to it and helps in continuous working. The more air gets delivered, the better it is!. For continuous use, you need to have higher CFM.
Can you adjust CFM?
Yes, you can adjust your compressor CFM according to your needs. But it can only happen for occasional use when you need less CFM for any tool to prevent it from any damage or when you want to provide more CFM to the compressor for more air.
Hamza is a founder of Compressors Insights. He is an Electrical Engineer having strong experience in Technical and Power tools. He has been helping electricians, and HVAC technicians regarding tool selection, and how to use power tools (Compressors, Pressure Washers, Multimeters, etc)