Air Compressor CFM Guide
Table of Contents
Air Compressors CFM are common in the home and the workplace. They can be used for a wide range of different purposes, including pneumatic systems, filling tires, filling gas cylinders, removing paint from cars and for undertaking DIY projects. Brought to you by Best of Machinery, there are so many effective ways to use an Air compressor CFM that we thought you should know more.
What is an Air Compressor?
An Air Compressor is a motorized tank of high impact air that is usually portable. It enables problem areas to be blasted because of the high volume of air being released at any one time in a concentrated place. The air can be controlled by a gauge so that the air pressure is helpful and not damaging to the job in hand. Very highly pressured air is very abrasive; if it can take the paint off a car, think how easily it could take the skin off your hand! Use the gauge to lower the pressure of the air so that it can be used for multiple other purposes.
The ideal pressure would be 30 PSI, though it is still advised that you do not let this air make contact with your skin or anything very fragile. It is possible to target the compressed air on to very specific areas thanks to a pinpointed nozzle available in many different shapes and sizes, with many models of air compressors coming with accessory kits as standard so that you can choose the right tool for whatever job you are wanting to do.
What Does CFM stand for in Relation to an Air Compressor?
When you are looking into purchasing an Air Compressor the term CFM is banded around frequently. It might seem like it is complicated, but actually, you’ll be pleased to know that it is not. Simply put, CFM stands for Cubic Foot per Minute. This refers to the amount of air that is being pushed down the hose and through the nozzle at anyone one time.
Obviously, the bigger the number in front of the letters CFM illustrates the more air being pushed through the compressor, the higher pressured that air is, the greater the speed it is being expelled from the compressor, and, basically, the more powerful the blast.
How to Determine the Correct CFM
When requiring the use of an air compressor to help you with a job either at home or in the workplace, it is important that you know specifically what the number of CFM is that you require. This will help you to complete a job properly and well, will keep your air compressor from being damaged and will also keep you safe while working. So that your air compressor can work to the best of its abilities you must be sure that any tools used alongside it are compatible before you begin work on any project. Here are a few popular examples for you to take into consideration:
- If you are wanting to use an air sander, you will need an air compressor of up to 10CFM and 100 to 120 PSI.
- If you are wanting to use an air nailer, you will only need an air compressor with a CFM of between 2 and 5 that offers PSI of 70 to 90.
Calculating the real CFM of your Air Compressor
The CFM of an air compressor is rarely represented accurately by manufacturers which can sometimes be problematic for users. The best thing to do is to test the CFM of your air compressor for yourself. This may seem complex but don’t worry, it is rather straightforward to undertake. You will do a much more accurate, safer and reliable job if you know exactly how much air you are using and the rate at which you are doing so.
- What is the air compressor volume? This needs to be in gallons and is always marked clearly on the tank itself.
- Divide the air compressor volume by 7.48 so that you can determine the specific amount of gallons in a singular cubic foot.
- Now release all of the remaining air from your air compressor.
- Start to refill the air compressor while recording precisely how long it takes for the tank to reach full. You must pay close attention to the gauge on your air compressor.
- Make a note of the PSIG at two different intervals, ideally as soon as you turn the air compressor on and as soon as you turn it off (when the tank has reached its capacity.)
- Next, subtract the second PSIG reading from the first.
Eg. Air compressor turned on at 80 PSIG and was turned off at 105 PSIG. The difference is 25 PSIG.
- Divide the difference between the two recorded PSIG recordings by 14.7 to decipher the amount of pressure added when the tank was being refilled. This is referred to in units of atmospheric pressure.
- Using the notes you have made of values from previous steps, take the tank volume calculated in cubic feet and times it by the atmospheric pressure. You will end up with a number that refers to the number of pumps that it took for your specific air compressor to have its tank filled in cubic feet.
- This number then requires a number to minute conversion. Take the number which refers to the specific number of pumps it has taken for your air compressor to have its tank filled in cubic feet and divide it by the number of seconds it took for this process to occur. Having done this, times the number by 60 and you will have successfully worked out the corrected CFM of the air compressor you are about to use.