If you’ve been in the air compressor industry for any length of time, you’re likely familiar with the acronyms PSI, CFM, and HP. These principles are essential in determining which size air compressor will fit your application – in fact, PSI, CFM, and HP are some of the most important elements to consider when selecting the best air compressor for your needs. In compressor terms, PSI is the amount of force that an air compressor can deliver. HP is not as important as pressure and flow in determining if your compressor will work for you, as newer & more efficient compressors can do more with less HP! Doing more with less HP will save you energy, as well as will give you larger returns throughout the life of the compressor.
Most air tools require between 70 and 90 PSI. Any light-to-medium-duty air compressor can easily handle 90 PSI, but you always want the compressor to supply more flow than needed. A pneumatic stapler might just need 0.3 CFM, while a framing nailer may require 2.2 CFM. Continuous use tools need more air volume and therefore have a higher CFM requirement. A constantly spinning sander might have a CFM requirement of 8,, while a nail gun, which requires single bursts of air might have a lower CFM rating of 2.8.
To better understand the difference between PSI and CFM, let’s learn what PSI means and what CFM means. Even though the example used water to describe the relationship between CFM and PSI, the concept is the same with air. Both the examples above share how PSI relates to CFM. When using air compressors, it’s crucial to have a sufficient CFM to power air tools and enough PSI to give the air power.
Knowing how much psi you need for an air compressor application will help determine how much cfm the compressor requires to operate your air tools effectively. Your tools’ cfm requirements can provide an idea of the cfm needed from your air compressor, but you will also need to consider the pressure levels required for the specific function this tool will be performing. If you’re using a single air tool, be it a 1/2″ drill or a 90-pound jackhammer, your air compressor’s minimum cfm rating should be the highest cfm marked for that tool.
While small, mobile at-home air compressors may deliver around 2 CFM, industrial air compressors with 200 HP can achieve air flow of around 1,000 CFM at 100 PSI. The Relationship Between Pressure and Flow. To do so effectively, air compressor operators must understand the relationship between CFM and PSI. In a compressed air system, the amount of pressure has a direct impact on the rate of flow. 100 CFM x 100 PSI = CFM x 80 PSI. 100 CFM x 100 PSI / 80 PSI = 125 CFM. 125 – 100 = 25 CFM. 25/4.5 = 5.5 HP. In this example, supplementing the existing compressor with a 7.5-HP compressor could effectively add volume and stabilize discharge pressure to the desired degree.
what determines air compressor cfm Related Question:
What air compressor CFM do I need?
Air tools made for general use with portable air compressors typically require 0 to 5 cubic feet per minute (cfm) at 70 to 90 pounds per square inch (psi), whereas with larger tools connected to stationary systems, the requirements usually exceed 10 cfm at 100 to 120 psi.
Is higher CFM better air compressor?
A compressor with a higher CFM rating can deliver more air and is better suited for heavier applications, such as operating air wrenches and framing nail guns.
Does bigger tank mean more CFM?
A straightforward rule for sizing an air receiver tank for a reciprocating air compressor is to take the tool with the highest CFM requirement at the required PSI, multiply that CFM requirement by 1.25 or 1.5, then round up to the closest gallon size.
What increases CFM for air compressor?
Five easy and effective ways to increase CFM on an air compressor are: Reducing pressure. Changing your outlet size. Hooking up two air compressors.
What is a good size air compressor?
American manufacturers measure air compressor tank sizes in U.S. gallons. There is a wide range of reservoir capacities on the market ranging from small but efficient 1-gallon models up to large commercial 80-gallon products. For your home garage, a compressor size in the 2.6-gallon to 20-gallon range should do nicely.
Does tank size matter air compressor?
Tank size matters—sometimes The compressors we chose have tanks ranging from 1 to 6 gallons. A larger tank holds more air and will allow you to use more air before the pressure drops and the motor kicks on to refill the tank. That might let you avoid stopping work while the compressor refills the tank.
Does HP matter in air compressor?
HP is not as important as pressure and flow in determining if your compressor will work for you, as newer & more efficient compressors can do more with less HP! Doing more with less HP will save you energy, as well as will give you larger returns throughout the life of the compressor.
What size air compressor do you need to run an impact wrench?
The average size air compressor you need is a 4-5 CFM @90 PSI for a ½” impact wrench. For instance, an impact wrench with a 1″ drive will need a 10 CFM @90 PSI, a ½” drive will need a 4 CFM @90 PSI, and ⅜” will need a 3 CFM @90 PSI.
How does PSI affect CFM?
CFM is measures at a given PSI and increases in direct proportion to the horsepower (HP) that is applied. While small, mobile at-home air compressors may deliver around 2 CFM, industrial air compressors with 200 HP can achieve air flow of around 1,000 CFM at 100 PSI.
How much HP does an air compressor need?
Air compressors typically have a horsepower rating between 1.5 and 6.5, though some larger, stationary air compressors can have up to 15 HP. If you are using standard electric power outlets, you’ll need an air compressor at 2 HP or less because standard AC cords require lower voltage to function.
WHY DOES CFM go down when PSI goes up?
You increase pressure by decreasing volume. Volume is measured in cubic feet. Therefore cubic feet per minute will be less as pressure is increased. Typically this relationship is in regards to mechanical advantage.
DOES CFM go up at lower pressure?
The CFM rating is always given at a specific PSI and even if it’s just a compress with a hose (effectively a small storage tank) you will get more CFM at a lower pressure than at a higher one.
What’s the difference between SCFM and CFM?
SCFM and CFM are both essential values that indicate the airflow rate in a compressor. SCFM measures this value based on ‘ideal’ temperature and pressure conditions, while CFM measures the ‘actual’ air flow rate. CFM is the recognized value for measuring the airflow rate in the United States.
What is the difference between single and two stage air compressor?
The fundamental difference between a single and two-stage air compressor is the number of times the air gets compressed. In a single-stage, the air is compressed one time; in a two-stage, it is compressed twice for double the pressure.
What is the advantage of a larger tank on an air compressor?
The bigger the air tank, the larger the reservoir of compressed air you have ready for use. With the time, energy, and maintenance costs cutting in half, buying an air compressor tank is a long-term investment you may want to make.
