If you’ve noticed that you’re not getting the airflow that you want from your air compressor, it can be frustrating. The good news is that increasing CFM on an air compressor isn’t difficult, and there are a number of things that can be done to accomplish this.

You can increase CFM on an air compressor by around 10% by decreasing the pressure, adjusting the regulator valve, connecting two machines, or adding a receiver tank. Should nothing work, you may need to buy a new compressor for around $1500.

Read on to learn how to increase CFM on an air compressor, tips for when you’re increasing CFM, and when to consult an expert.

What Is CFM?

Before discussing how to increase the CFM on an air compressor, let’s review what CFM means and why increasing it is essential.

A cubic foot per minute (CFM) measures volume flow rate inside a duct or pipe system in units of cubic feet per unit time, usually expressed as cfm/min or milliliters per second(ml/s). 

Increasing the CFM may be necessary if you feel as though your air compressor doesn’t have enough power or operating time. If you suspect something is off, start by diagnosing the problem.

How to Check the CFM of an Air Compressor

If you don’t know what your air compressor is capable of, it can be difficult to upgrade it. To find out what your compressor’s CFM is at a particular pressure, do the following:

Step 1: Locate the regulator knob on your compressor. You’ll need this for step 3.

Step 2: Turn off the power and allow the unit to come down from full pressure slowly, which should take about 5-10 minutes depending upon tank size and duty cycle. Make sure everything is safe before doing any work on a pressurized system!

Step 3: Locate the drain cock or plug that creates a pathway for airflow just below where air enters into the tank from the compressor.

Step 4: Turn the drain cock or plugin an open position, activate your compressor by turning it on, and allow the pressure to build to the desired pressure.

Step 5: Use a reliable regulator gauge calibrated in the same units as the compressor to read the output CFM. Turn off the compressor and then turn it back on to check that there aren’t any leaks.

Step 6: Repeat steps 2-5 three times, document the results, and find the average your compressor is capable of.

Once you’ve located the regulator knob and figured out your compressor’s output CFM, you can increase it by completing the steps below.

How to Increase CFM on an Air Compressor

There are a few things that you can do to increase the CFM on your air compressor.

Ways to increase CFM on an air compressor:

  • Decreasing the pressure
  • Adjusting the regulator valve
  • Connecting two air compressors together
  • Attaching an additional receiver tank 

By doing one of these three things, you should be able to regulate the CFM of your compressor.

Decreasing the Pressure

Reducing the pressure is just one way to get your air compressor’s CFMs up.

Reducing the pressure in the system by dialing down a regulator causes CFM to increase respectively and the power to remain steady. This gives the compressor time to catch up by decreasing the cycling frequency. Don’t use this method for drastic increases in CFM greater than 22% or so. 

For example, if your air compressor has a 3 CFM rating at 80 PSI, you should be able to power a device that operates at 5 CFM with 60 PSI.

This method also ensures the reliability of the compressor by not overworking it. As long as your tools require a lower PSI than your air compressor, this is a great option to increase CFM.

Adjusting the Regulator Valve

Another way to increase the CFM on your air compressor a small amount is to adjust the regulator valve. This will not increase the power, but it does allow for a more steady flow of CFM, which is great if you need to power an appliance.

Adjusting the regulator valve does take some time and effort, but you can get an extra 6% in CFM if adjusted correctly.

To do this:

  • Get a regulator gauge that measures air pressure between 0 – 150 PSI. Hook it up to the standard main valve on your air compressor, which should be set to 100 PSI. 
  • Turn the regulator screw until it matches the desired output of 130 PSI (usually marked right on your regular main valve body). 
  • Hook up the regulator gauge again; however, don’t make any adjustments this time. 
  • Turn the main valve control to 130 PSI. 
  • Now, turn the regulator screw back until it matches up with 150 on your gauge. Most gauges are accurate +/- 2%. 
  • This should give you about a 6% increase in CFM depending on the specific compressor and air tank size.

As I mentioned, this won’t give you any more power, but it might make your air compressor more efficient. This will save you money on your electricity bill in the long run!

Connecting Two Air Compressors Together

You can also increase the CFM on your air compressor by connecting it to another air compressor. This could be a connection in parallel or series, depending on your needs.

Connecting two compressors together in parallel will give the same CFM for both compressors, but one of them will have more PSI than the other. Joining two compressors in series means that both compressors will share PSI between them. If one has 10 PSI and the other 20 PSI, they can provide up to 30 PSI when connected together in series. 

One thing you have to keep in mind when connecting two or more air compressors is that they might need their own power supply. Otherwise, they’ll fight for voltage and fail.

To do this:

  • Use a t-piece air fitting to connect the outlets of both air receiver tanks.
  • Attach the compressed air hose to the outlet of the t-piece.
  • Lastly, connect the air hose to your power tool of choice.

With this method, you will need to buy another air compressor – making it the most costly solution. It also requires adjustable air compressor pressure switches.

Attaching an Additional Receiver Tank

The last option for increasing CFM on your air compressor is to add another receiver tank to your machine.

Adding another receiver tank will increase your air compressor’s running time and amount of CFM. For example, if your air compressor has a CFM of 5 with its original tank, attaching another receiver tank can increase its overall CFM to 10. 

The pressure in the additional receiver tank will depend on your air compressor.

To do this: 

  • Attach the air hose to your compressor’s outlet.
  • Add an additional receiver tank to your machine, ensuring it is compatible (PSI limit, size, etc.).
  • Connect the regulator and pressure switch to both tanks.
  • Turn on the main power supply and adjust the pressure settings for both tanks.

This option allows for the air compressor to cool down longer and enables your tools to run more efficiently, given the greater reserve of compressed air in the tank. It also is less costly than buying an entirely new air compressor.

Tips When Increasing Your Air Compressor’s CFM

When looking to increase your air compressor’s CFM, there are a few tips to keep in mind.

Tips and Tricks:

  • Know your air compressor
  • Check for leaks
  • Add refrigerant 

Tip #1: Know Your Air Compressor

When increasing your air compressor’s CFM, it’s essential to make sure that you know the size, power supply, and type of air compressor. You can find this by googling your model or checking out the manual.

You will also need to know the PSI limit (typically around 140 PSI) of your air compressor before adding another receiver tank or any other upgrades. Use the measurement on the pressure switch gauge to do this.

If you are connecting two compressors together in series or parallel, try to equalize the PSI’s on each. You may also want to invest in an adjustable regulator if you are connecting two compressors in parallel. 

Tip #2: Check for Leaks

Leaks can come from several different places. You’ll want to check near fittings, lines, and valves for any signs of a leak.

If you find an area where it seems like there might be a leak, check the connection with soapy water. If you see bubbles in your gauge or regulator, clean them out and test again. It’s possible that one of your accessories is not working correctly, so be sure to check each part of your machine.

If the issue persists after this process, you will need to replace these pieces as leaks can reduce pressure in your air receiver tank.

Tip #3: Add Refrigerant

The last tip when increasing the CFM of your air compressor is to add a refrigerant.

There are two different types of refrigerants that can be used in an air compressor- CO2 and Nitrogen. If your tank does not have enough pressure for the desired CFM, then you will need to add either CO2 or Nitrogen gas to the tank. 

As you add refrigerant, you will want to make sure to monitor the pressure on your tank and make any adjustments before continuing to add more fluids.

Consult an Expert

When you’ve tried all of the above recommendations, and nothing seems to help, it may be necessary to reach out to a knowledgeable professional.

The experts at your local welding supply or hardware store can advise how to increase CFM according to the make and model of your air compressor. Even better- their advice is free!

Sometimes it might be as simple as just needing a new air compressor altogether. Expect to pay around $1500.

In Summary

Increasing your air compressor’s CFM is a simple process that you can do at home.

You have the option of adjusting the regular valve, decreasing the machine’s PSI, connecting two compressors together, or adding another receiver tank. Given there are no leaks in the system, each of these methods can help to increase CFM by about 10%.