Different air tools run efficiently on different CFM ratings. Have you ever wondered how to increase CFM on air compressor? Because I have. I needed to increase the CFM of my compressor, so I gathered everything I could.
There are two ways you can effectively use to increase your air compressor’s CFM. One is by decreasing pressure, and another is by connecting 2 compressors together.
Understanding how to decrease your air compressor pressure and connect two compressors requires digging a bit deeper. If you are curious, I’ve explained the details below. But first, let me tell you what CFM actually is.
What Does The Term CFM Mean?
CFM is a crucial indicator of any air compressor. It’s an abbreviation for Cubic Feet per Minute. In simpler words, it means how much air it can release per minute.
The air is measured by volume here, and the flow rate is indicated by the minute. If a compressor comes with a 10 CFM rating, it means it’s capable of releasing 10 cubic feet of air per minute.
You must know your air compressor’s CFM because matching the CFM rating with the air tools is compulsory.
How To Increase CFM On Air Compressor?
As I’ve already mentioned before, you can increase your air compressor CFM using two different ways. I’ve included a detailed explanation below about how to increase CFM on air compressor using both methods. Let’s get started.
1. Decreasing Air Compressor’s Pressure
If you didn’t know already, air compressors initially take air inside the tank. The air is then pressurized inside the tank. The compressed air is then released in the air at a specific rate which is referred to as the CFM rating.
Not all air compressors come with the same power level. How powerful an air compressor is, depends on the machine’s CFM and air pressure. If we express it in terms of mathematics,
Power is equal to Pressure X (Volume/Time). The volume per minute is referred to as CFM. If you wish to keep the power constant, you will have to lower the pressure when increasing the CFM.
You can easily adjust the air pressure by using the regulator. Dialing down the air pressure regulator will make sure that the air enters the tank slowly and create less pressure inside. And low pressure means high CFM.
Let’s elaborate on this with an example. Let’s assume you own a compressor that offers 10 CFM at 10 psi. It means your air compressor will give you 10 CFM when the air pressure is 90 psi.
If you lower the air pressure from 90 psi, you will get a CFM of more than 10. That’s how you increase your air compressor’s CFM.
Remember that you can’t cross a specific limit by using this method. But it’s effective enough and doesn’t cause any damage to your air compressor. It’s effective, easy, as well as safe.
2. Connecting 2 Compressors
One downside of the prior method is it can’t provide you with more CFM rating than the compressor’s maximum limit. Sometimes, you will need more CFM than your air compressor limit. What do you intend to do then?
An effective method of increasing your air compressor’s CFM is to connect 2 compressors together in such situations. If you want more than 5 CFM when your compressor’s maximum capacity is 5, you can increase this number beyond your machine’s capacity by using this method.
Let’s do simple math to make it clear. If you are adding two compressors, both having a 5 CFM rating, you will get 10 CFM when they are connected.
If you are confused about how to connect two compressors, follow the steps below-
- Use two separate hoses to connect the two separate compressors. Now, take one other hose and connect it with the two hoses. Make sure there are three holes in the third hose.
- The third hose will work as a medium for both input and output. Two holes connected with two hoses will work as inputs, and the other hole will work as an output.
- Connect your third hose’s output with your air tool. That’s all you will have to do.
It’s the best method when you want a higher CFM than your existing compressor can provide. But, there is a question that pops up.
If you only have one compressor, do you buy a low CFM compressor to connect it with the prior one? Or do you buy a higher CFM air compressor to get more complicated work done?
The answer, of course, depends on your preference. If most of your works require a higher CFM rating, I would suggest you go for a higher CFM air compressor. If most of your works require low CFM but occasionally need higher CFM, you can buy a lower CFM compressor to connect with your old one.
If you already own two compressors, there’s no need to have second thoughts. Connect them, and you should get your work done in no time.
Two things to remember when connecting multiple air compressors are-
3. Check Valves
To ensure that the airflow can’t return to the compressor but can blow away from the compressor, check valves in the connecting line are compulsory.
4. Pressure Adjustment
Both your air compressor must have the same kick in and kick out the pressure. This way, you are ensuring that both your air compressors are doing the same amount of work to run your demanding air tools.
Moreover, check if both compressors will provide you with enough CFM required by your air tool. If they can’t, there’s no point in going through this method. You will have to buy a new air compressor anyway.
And if you wish to buy one, most of the time, it’s a wise choice to go for a high CFM air compressor because you already have one with low CFM.
In Case You Want To Decrease The CFM
The next thing that comes after how to increase CFM on air compressor is how to decrease the CFM. This one is relatively simpler. There is already a CFM regulator on your compressor for doing it.
When you quick-fill your air compressor’s tank, the CFM decreases. You can do it by dialing down the CFM regulator on your compressor. Of course, there are cautions to follow.
A sudden drop in CFM rating will cause improper tank filling. This will result in your air tool stopping midway because there will be a lack of air in the tank.
If you frequently need lower CFM, I would recommend you go for a low CFM compressor. Far better than dialing down the CFM level on a high-capacity air compressor. You will need some initial investment, but you will save your compressor from potential damage.
Reasons Why Proper CFM Rating Is Essential
Likey, you are already aware of why you need an exact CFM rating. The most primary concern is the well-being of your compressor and air tools. When you don’t match the CFM rating of your air compressor with the tools you are using, there is a probability you will ruin them both.
In comparison, when you do follow the instruction provided by the manufacturer, you can extend your air tool’s life and experience efficiency from the tool. The more carefully you use any device, the longer they’ll provide efficiency.
But that’s not all the reasons for getting the CFM rating right. If you modify your air compressor to achieve desired CFM rating, the tank will require more time to fill. And when it comes to using these devices professionally, proper time management doesn’t have any alternatives.
How To Identify An Air Compressor’s CFM?
All air compressors come with an instruction manual. You should find your air compressor’s CFM on that manual. In case you forgot your compressor’s CFM level or lost the manual, there’s a way to calculate the CFM.
- First, you will have to find the tank volume in gallons.
- Then, you have to divide the compressor’s tank volume by 7.48. This will let you convert the volume into cubic feet. Here, 7.48 gallons is equal to 1 cubic foot.
- Empty the air compressor’s tank and then refill again.
- While refilling the tank, note the time you see in the gauge. It’s shown as PSI that stands for pounds per square inch.
- Monitor the time and find out the difference between the kick in and kick out time. If your compressor’s kick-in time is 70 with a kick-out time of 90, you’ll have to subtract 70 from 90, i.e., 20 psi.
- Divide this value you found by 14.7. That’s the pressure in ATM.
- Now multiply the pressure you found with the volume and then divide by 60. The value you find is your CFM. Here, CFM= pressure*volume/60.
Cautions To Follow While Increasing CFM
Sometimes, even when you know all the rules by the book, you need someone to tell you what to do and what to avoid. This time, it’s going to be me telling you the rules. When you are adjusting your air compressor’s CFM, keep the following things in mind.
- When you are lowering the pressure to increase CFM, don’t jump to the lowest settings immediately. The energy consumption will worsen if you alter the pressure so drastically all of a sudden
Make sure you dial down the pressure gradually and observe the outcome while doing so at each limit.
- Using the second method, you should occasionally adjust the compressors’ pressure switch settings to prevent the same compressor from overworking.
- Never alter, block, or get rid of the relief valve when you are making changes to your air compressor. The manufacturer carefully positions these settings to ensure our safety when using the air compressor.
- Avoid stringing hoses across the floor. It can cause you to fall over by tripping. Believe it or not, it’s a common incident. It’s best if you suspend them overhead if possible.
- Before you connect the machine to a power source after you’ve made your modifications, make sure that you haven’t pulled any tool at the trigger. It’s essential to avoid accidents and damage to the tools.
What Are Others Saying?
Frequently Asked Questions
Q. How much CFM do air tools require?
No all air tools require the same level of CFM to function properly. For example, a half-inch impact wrench needs about 5 CFM. In contrast, a framing nailer needs about 2.2 CFM to operate. An air tool like a pneumatic stapler will need only 0.3 CFM to run.
Q. What is a good CFM rating for my air compressor?
4 CFM with 100 PSI is a good CFM rating for an air compressor. However, it depends of the type of air compressor you are using.
THE lowest CFM air compressors usually provide a CFM of 0.5 at the maximum point. A high-powered compressor can provide from 8 up to 10 CFM.
Q. What’s the difference between CFM and SCFM?
CFM or cubic feet per minute of an air compressor indicates the air volume that is flowing out in a minute. There isn’t any standard pressure set for CFM.
In comparison, SCFM stands for Standard Cubic Feet per Minute. A standard pressure and temperature set for SCFM. It’s measured based on the standard and can vary.
Q. What’s the difference between PSI and CFM?
PSI is a measurement of pressure level. It stands for Pounds per Square Inch. On the other hand, CFM indicated the volume of pressure releasing per minute and stands for Cubic Feet per Minute.
My final suggestion for you is to match your air compressor’s CFM rating with the air tools you are using before getting an air compressor. This way, you won’t have to increase the CFM and go through all the trouble.
However, if you already have an air compressor that doesn’t match your air tools, following my methods will tell you how to increase CFM on air compressor. I hope you don’t have any other questions arising in your mind regarding this issue.