How to get more CFM out of the air compressor?

When anyone buys an air compressor for the first time, usually use a lightweight compressor. A lightweight compressor means that the compressor has a small-sized tank. Small-sized tanks or low-pressure compressors will not be able to provide enough amount of air with growing needs if you have the same problem with the CFM and want to know. How to get more CFM out of the air compressor? I’ll help you to solve this problem.

Pneumatic tools are more affordable than their electric version. If the air Compressor can provide sufficient airflow the tools will work impressively. So, enough airflow is important to perform your tools efficiently. Then you will get the perfect result as you thought. Every air tool requires different CFM ratings to run effectively. We know that air compressor is related to many measurements with a little complex mechanism. But some adjustments with proper size can increase your air compressor. Please, follow my article. I will give you some practical techniques.

What is CFM?

CFM is the abbreviation of Cubic feet per Minute. The term for expressing gas, air, and liquid flow in a volumetric unit of measurement is cubic feet per minute or CFM.  In a word, it means how much air an air compressor can release per Minute. The air and flow rate are measured accordingly to volume and the Minute. CFM is a very regular term in ventilation engineering and industrial hygiene also. It expresses the volumetric rate of any type of gas or air in or out of a specific space. If the CFM coefficient is higher then more amount of gas or air is being pushed into that space. 1 CFM is near about 0.47 liters per second. If you buy a compressor with a rating of 10 CFM, it can release ten cubic feet of air per Minute.

How to check the compressor’s CFM?

Before increasing the CFM, you must know the CFM and CFM reading. Then you can easily understand the terms of the techniques. Follow these steps to check the present compression of your tank.

  • There is an attached Knob opening the tank. Turn the knob to turn off the tank.
  • Drain all the air. You can use the earplug for safety.
  • You have to read the tank to know the level of initial reading. It will determine how much you will fill your tank based on the capacity of the tank.
  • You can use a stopwatch when you are filling the tank. You will measure the time to fill up the tank. Usually, a 60-gallon tank will take 10 minutes to fill up.

Air compressor CFM chart

The . Air compressor CFM chart will help you to measure CFM for your required tool.

Air pressureConsumed Air
ToolsPounds per Square Inch (PSI)Cubic Feet per Minute (CFM)
Impact wrench 3/8 – 1/270-905
Impact wrench 3/4 -1 3/470-9020
Air ratchet70-903-5
Tire changer125-1502
Bead breaker125-15012
Blow Gun70-903
Screwdriver #2-6 Screw70-905
Paint spray gun70-904
Nailers/ Staplers70-902-4

There are some techniques how you can increase CFM from your air compressor-

Following some techniques will help to get more CFM from an air compressor. Adjust the measurement between tools and extra added parts to increase the CFM. 

If you want to increase CFM, these techniques can help here. There are several ways to improve the CFM of an air compressor. Let’s discuss them one by one.

Use an Auxiliary Storage Tank

Add an extra air receiver tank to your compressors. You will get a massive amount of stored air from the compressed air system of your compressor when you want unstoppable pressure to operate the motor of a pneumatic tool for a long time. The air compressor auxiliary tank will be adequate to increase CFM.

Hook up Two Air Compressors in Parallel compressor

Adding another compressor is not as easy as it sounds. Your compressor has a brand, specific model, and CFM. So if you want to pair the same brand, the same model, and the same CFM output. Or you want to add a different compressor from another brand and model. That has an additional CFM output also. According to these options, I have divided these techniques into two parts to add the second compressor.

  • Choosing the same compressor with the same brand
  • Choosing another compressor with another brand

Choosing the same compressor with the same brand

Adding one extra compressor of the same brand and model and CFM will almost double your present CFM. In this method, CFM increases in the pumping system simultaneously; it provides higher CFM to the air compressor tank. Here tee air fitting will be suitable for connecting two air compressors. The outlet of the tee will connect your airline to your air tool. There are no complex synchronizing control issues. You can connect compressors and run. This is the great advantage of this method.

Choosing another compressor with another brand

You are choosing another compressor with another brand. You have to face some challenges in this method. If you have an air compressor of 15 CFM and another air compressor of 10 CFM in good condition, your storage is in good condition. And you have already decided to connect the outlet of your two outlet receivers with a Tee piece of fittings. After that, click the hose to the outlet to secure your air tools. Look! Now you have a friendly compressed air system. It will provide continuous airflow at the rate of 25 CFM.

Decreasing pressure to increase CFM

 CFM is the airflow rate of the air compressor. An air Compressor has a pump. Every pump has a rating in horsepower. If you multiply the pressure by the CFM, you will get horsepower. If you will not alter the compressor’s power over the limit, it remains the same. If you reduce the system pressure, in result the CFM will increase. The outlet pressure has been set before and your compressor’s CFM changes depending on it.

Here is an example, compressors rated by “X” CFM at 90 PSI, and something good at 45 PSI. We can say that a compressor rated 5 CFM at 90 PSI if you determine the pressure at 45 PSI then get 6 or 7 PSI  is possible that may b the distinction within successfully managing your tools or not. That is the inversely balanced relationship between CFM and PSI at the outlet of the air compressor makes adjustment advantage with reason. You must make sure you look at your pneumatic tools requirements, while their working load is under 90 PSI, you will receive a little boost of CFM if you were to down the pressure.

Enhance the Efficiency of Your Air Compressor

The proper way to increase the airflow in your system is to ensure that your air tools are utilizing all the air your system produces. The following steps will help you to enhance the efficiency of your air compressor-

 Fix leaks in the system

 It is widespread to find leaks in the system. But sometimes, you can detect it by sound and repair it. Sometimes it’s challenging to find out the small leakage. So check carefully. You can find leaks around hose connections, joints, and pressure regulators. If any parts are not in good condition, then change those parts. You’ll get 100% airflow through your tool when you seal all leakage. 

Select low-pressure drop hoses

Some low-pressure drop hoses have smooth walls. You can find some pressure drop charts available online. Specific diameter hose and pressure loss are mentioned in the charts. Collect the chart. Measure the length of your hose and diameter.

Reduce the total length of the hose from the tank to your tool

Air moving through the hose will meet friction against its wall. In that way, the air loses its energy. So how long the hose has that much energy, it will fail. If there are any fittings or crimps, these are also responsible for losing friction.  

Reduce the number of fittings between your compressor and tools

There is one crucial thing you have to notice. That is the fittings between your compressor and tools. When air hits a fitting every time, it loses pressure, speed, and overall airflow. Fittings are valves, tees, couplers, reducers, and plugs.

Don’t forget subsidiary equipment.

When you use a subsidiary storage tank, Intel hose, or a different compressor, confirm that you reduced the losses in that stuff.

Check valves

You have to check valves in the connecting line. You have to make sure that the airflow will not return to the compressor but it will blow away from the compressor.

Pressure adjustment

If you use two air compressors, they must have to maintain the kick-in and kick-out pressure. In this style, you can ensure that both of your air compressors are performing at the same level to run your desired air tools.  

Besides, check that your compressors are providing you with enough CFM according to the demand of your air tools. If they are not supporting then buying a new compressor will be a good decision.

When you wish to buy a new compressor go for the higher CFM one. Because you have already a low CFM compressor.

Verdict on Increasing Air Compression

There are some options to increase the CFM. But not enough for a regular user. Nobody wants to put high pressure on his tank.

Sometimes accidents take place when you put high pressure on your tank. The air compressor can explode. Or it can provoke any manufacturing defect of the product.

So, here is some advice for you-

  • Don’t overpower an individual tank; buy an additional air compressor to increase the quantity.
  • Check the appropriate CFM when you will buy the tank.

To receive more CFM out of your air Compressor you have to follow some techniques. Such as adding an auxiliary tank, adding another air compressor, increasing the efficiency of your air compressor, and decreasing pressure to increase efficiency. Remember, to check valves and adjust the pressure while adding another compressor.

[Detailed answer] How to get more cfm out of the air compressor?

Step1: Pressure reducing

To increase the output airflow please from your compressor, reduce the output pressure. When you give pressure on your air tank compressors, you can use a certain amount of air. And you do it until the air compressor starts its work again. When the tank is pressurized at a higher level then increase the air volume to charge your tank. The same air rating compressor adjusts the same power compressor. And you have to get more air compressors by multiple volumes of the time. If the energy is the same then you can count it in this type like 

  • Previous pressure multiple by cmf = cmf multiple with new pressure. 

It’s just an example of counting the pressure. Suppose you set 125 or more than that pressure and get only 5 CMF. That means you want to see how much airflow you will get more air in 90 PSI. 

So you have to multiply 125 with 5 CMF= New CMF multiplied by 90 psi. Then you will get new CMF in (125 x 5) ÷ 90 = 6.94 cfm. Now, you have the confusion, how many times the air compressor can go? Ok, let me tell you, I observed, that the compressor goes for a long time if you low your out pressure. As the volume of air is at a low rate. And it all depends on tools. What type of tools do you want to require? You can use tools for a long time at a lower pressure. The accurate amount of airflow may not produce what you calculated. The reason is the demand for air can keep up the time and make air compressors easier. Because air depends on tank pressure and output pressure. So the calculation of the air compressor may not be equal. 

Suppose, you use the air tank, and you will notice that the air pressure will decrease. When the pressure is the huge difference the airflow goes to the highest and makes the tank fully charged. Let’s calculate it 

The velocity of the outlet ^2= Discharge of coefficient × Outlet area (2(Psi1-Psi2)gravitational constant× density of air, which means v2=c ×A (2 (p1-p2)g× ρ). The gravitational constant requires 32.2 lbm× ft/lbf× s^2. And c which is the opening tube for free requires 0.6. The very important thing is if you take the psi in pound-force stand by square, the density should be taken as a pound per cubic foot. So when you calculated, convert between feet and inches. As well as convert the second to minutes which is a gravitational constant.

Suppose you take 0.11 inches outlet and the pressure is 125psi with 90 psi air, then the cmf is 21.44. In this way, you can calculate any starting airflow at lower or original pressure. If you take 95 to 90 psi then the equation will be 8.10 cfm. The density of the airflow is decreased when the tank pressure is low.

Step 2: Make a change in outlet size

You need some tools and minimum pressure to change and operate. Tools can increase enough pressure and prevent the decrease. You have to expand the size of the hose on the air compressor so that you can increase the airflow of the outlet. In the Bernoulli equation hose size was the factor and now I can show you by plugging different sizes of hose how you will increase the outlet airflow. 

So take half inches to the hose in diameter, and the area is 0.19 square inches. Suppose you take three divides by 4 tube inches hose whose area is around point forty-four square inches. To measure the tools use calipers and check your tube specifications to calculate the actual diameter. In that equation, I use A= πr^2

Using the above pressure which I took in my first point, I can show you the difference between the two different size tubes and show you the change of airflow. Again I take the cmf 0.6 and multiply it by 0.19 inches×21 ft^2 × 144 inches × 260 sec/min × [{2×(one twenty-five ibfin- 90 ibfin2) ×144 inches × 21 ft^2×32.2fts^2)×0.534ibft^3}]. To calculate the air compressor use cubic feet per meter and take the flow rate.

Calculating the above equation, my cmf is thirty-seven. To increase the airflow, you have to increase the actual value. 

Step 3: Connecting two air compressors in series

Similar to the last recommendation, but with a focus on pairing up two air compressors of various CFM, brands, and models. It’s as easy as it seems. not the method, but the idea.

If you connect two compressors with respective CFM ratings of 10 and 5 to each other, you will receive a 15 CFM continuous flow rate.

The following actions must stand taken to link the two compressors:

  1. Using a t-piece air fitting, connect the air receiver tanks’ outlets.
  2. Attach your compressed air hose to the t-output. piece’s
  3. Connect your air hose and air tool.

An illustration of a T-style air manifold used to link two compressors:

Considerations for Combining Two Different CFM Compressors

  • Excellent for continuous usage of air tools because the system’s pumping capability has a higher CFM
  • acceptable for sporadic air tool use
  • Not as economical if you get a new air compressor.
  • If you use a spare compressor or borrow one from a friend or neighbor, it can be more affordable.
  • There will be a need for adjustable air compressor pressure switches.
  • To properly design the air compressors in proportion to the working CFM of the air tool, it is still necessary to examine the DUTY CYCLE of the air compressors.

Step 4: Utilize a backup storage tank

Reducing the pressure on your regulator is an extension of the concept in our first approach to assist in increasing the airflow through your air compressor.

Reducing the outlet pressure enables you to produce more airflow for a longer length of time, as we discussed in the prior examples. The utilization of an auxiliary storage tank follows the same logic. The pressure will decrease more gradually as you work with your tools because the storage tank’s volume is more than what you could achieve with just your compressor.

CFM stands for cubic feet per minute, so keep that in mind. A cubic foot of air will exist used in one minute if you pass one cfm through your tool. Since one cubic foot of air is equivalent to around 7.48 gallons, you could use up all the air in a 20-gallon tank in a matter of minutes if you used one cfm continuously and the air compressor never turned on to refill the tank.

Naturally, when the pressure declines, you won’t be able to maintain your desired cfm, and eventually, your air compressor will probably start cycling to raise the pressure in your tank. You will be capable use your tools for a lot longer if you do this.

Step 5: Increase Your Air Compressor’s Efficiency

We repeatedly highlighted that system losses and inefficiencies could lower the airflow you get from your tools in the previous techniques to boost the airflow on your air compressor. Making sure that all of the air your compressor produces exits your tool is the simplest approach to increase airflow in your system.

Several strategies exist suggested by Quincy Compressors for minimizing losses in your air compressor’s output airflow:

  • Fix any systemic leaks: Hissing noises are frequently produced by air leaks, though some minor ones might not be audible. Fittings like hose couplings, pressure regulators, joints, and disconnects are frequently the site of leaks. Verify the condition of each gasket and replace it if the rubber becomes hard, worn, or damaged.

To assist stop air leaks and properly tightening down all threaded fittings without over-torquing, cover fittings with plumbers’ tape. To find leaks that aren’t audible when in use, carefully spritz soapy water around fittings using a spray bottle. Disconnect any fittings that need to be tightened furthermore by turning off the compressor.

  • Shorten the hose’s overall length from the tank to your tool: There will exist friction between the air and the hose walls as it moves. The longer the pipe, the more energy it will lose due to friction. In addition, the system will experience friction losses if there are any kinks, crimps, or fittings.
  • Choose hoses with a low-pressure drop: The interior walls of low-pressure drop hoses will be smooth. There exist numerous pressure drop charts online that illustrate the potential pressure loss in hoses of a certain diameter. Measure the diameter and length of your hose.

For instance, simply 50 feet of a 12″ hose could see a 10 psi pressure loss. Contrary to lowering the regulator’s pressure setting, the pressure loss in the hose slows down the airflow as it leaves the hose.

  • A smaller number of fittings should connect your compressor to your tools. Your system loses a lot of pressure because of fittings. Valves, couplers, plugs, tees, and reducers are a few examples of fittings. The pressure, velocity, and consequently total airflow of the air are lost each time it encounters a fitting.
  • Don’t forget the extra gear: Check to see if you’ve eliminated any losses in the additional compressor, storage tank, or inlet hose if you utilize those tools.

FAQ

What determines the CFM of an air compressor?

First, determine the volume of the air compressor’s tank in gallons. Usually, the manufacturer marked it on the compressor’s tank. Here 7.48 equals the number of gallons in one cubic foot. So, divide your tank volume by 7.48. The result of the division is the tank volume in cubic feet. Now, empty your compressor by releasing all the air from it. Refill the compressor. Record the time and PSI at the time of kicks in and kicks out. Subtract the PSI of kicks in from the PSI of kicks out. Now divide the result of your subtraction by 14.7. The result will give you the amount of pressure being added at the filling cycle time of the tank, in other words, atmospheric pressure. Multiply the volume (cubic feet) and the pressure (during added the tank filling cycle). This is the number of cubic feet that the compressor pumps. Then convert the number to minutes and multiply this result by 60. Now this result is the CFM of your compressor

How do you increase compressed airflow?

Increasing compressed air flow is essential to running your air tool efficiently. The following techniques will help to increase tight airflow- 

  • Increase the efficiency of your air compressor 

  • Add an extra tank 

  • Add a new air compressor with your old one 

  • Decrease pressure to increase CFM.

What happens if CFM is too low?

If CFM is too low, you will not be able to run your air tools. Poor CFM can not run the air tool continuously. So it will not meet your expectations. Sometimes due to low CFM, your device will not work.

How do you adjust CFM?

How do you adjust CFM? To change CFM in an air compressor, you have to allow more time for your air compressor. Then the air compressor can keep the pressure up the tank. When dialing the regulator downside, the tool will operate to the lowest settings.

DOES CFM go up with PSI?

No, the relationship between PSI and CFM is inverse. Therefore, if the PSI of an air compressor system existed to stand decreased, the CFM of the compressor’s outlet would be slightly increased. The CFM at the air compressor’s tank outlet fluctuates according to the outlet pressure that exists set, as is well known. A compressor, for instance, has ratings of 5 CFM at 90 PSI and 6 CFM at 50 PSI.

How does PSI affect CFM?

What they measure is different between PSI and CFM. CFM measures volume, whereas PSI measures pressure. Performance standards for air compressors and air-powered equipment include PSI and CFM. Together, they show the highest air volume and pressure that an air compressor can generate to power air tools.

Is higher CFM better air compressor?

Higher CFM would necessitate a larger air compressor, but bigger isn’t always better, unless you think of it that way, hehe. The amount of CFM that the air tools and machinery would require if they were all used at once in a body shop, plus at least 30% of that number, will help you choose the best air compressor to meet current and future demand. Alternatively, you can divide the shop into different stages of production to reduce that number and run multiple compressors, which may result in less dropoff which can be effective.

Conclusion

 If you are using an air compressor and your air tool needs more CFM to run efficiently, my methods will help you. There are many ways to increase the CFM of your compressor. You can add an extra tank, add a new compressor, decrease pressure, etc. 

All techniques will help your compressor to run your air tools efficiently. But all processes are a little complex. Here is a suggestion for you if you are a new user, buy your compressor according to the demand of your air tool. Then you can avoid this extra hassle of increasing CFM.

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