- Pressure – Common variants 100, 125, 140 – (piston), 175 psi. The manufacturer of the tools or equipment being used will specify the pressure required. TIP:Use the lowest possible pressure variant required – to save on electrical cost.
- CFM – ***IMPORTANT*** to determine cfm you will need to know how much cfm your tools require. This can be found either in the literature provide by the manufacturer or possible online from the manufacturer. We have provided a list of commonly used tools and cfm guides below (we recommend using exact figures from the manufacturers whenever possible).
- Phase (of motor) – A three-phase circuit provides greater power density than a single-phase circuit at the same amperage, keeping wiring size and costs lower. Tip: If 3 phase power is available –use 3 phase power to save on electrical cost.
The next thing to consider is what is the right fit for your application
or ROTARY SCREW compressor.
- How often are you using air (continual or
- Is the quality of air important (oil carry over)?
- Is noise
a consideration (do you or your employees work nearby the compressor).
Duty Cycle – Piston type
compressors are not designed to run on a continuous basis (duty cycle is less
CFM – Calculate all cfm requirements that may be needed at one time. We have compiled a list with some common cfm requirements listed below (this is not a substitute for actual cfm data supplied by manufacturer).
Phase Power – Piston compressor is your only option.
Use – a piston compressor may be the right fit.
70 cfm required – piston compressor may suit your needs.
use (100% duty cycle) – rotary screw compressor a must.
air is important (oil carry over) – consider a rotary screw compressor.
noise level – Consider a rotary screw compressor.
70 cfm required – a rotary screw compressor needed.
Pressure (PSI – pounds per square inch) – PSI is the measure of
pressure that a compressor can produce in pound per square inch of space.
Cubic Feet per Minute(CFM) – CFM is the amount (volume) of air velocity that
passes through a medium. Using a
water hose as an example – where you can measure the quantity of water that is
possible to pass through in 1 minute.
Electrical Phase– Your options for your air compressor is single-phase or
three-phase. Single phase is normally
found is a residential setting where three phase is often found in an
Duty Cycle– duty cycle is the amount of time the air compressor can
run continuously, compared to the time it needs to rest. The
“standard” for testing the duty cycle of an air compressor will
include a controlled temperature (72° F) and will be tested at a pressure of
100 PSI. (Ex: a compressor with a 50% duty cycle is able to run half the time
and will have to rest for the same period of time)
General CFM figures to use as examples listed below.
When determining the size compressor to purchase – use the CFM requirement for each tool specified in the manufacturer’s documentation.
CFM @ 90 PSI
|Angle Disc Grinder||5-8|
|Drill, Reversible or Straight -Line||3-6|
|Impact Wrench 3/8″||2.5-3.5|
|Impact Wrench 1/2″||4-5|
|Impact Wrench 1″||10|
|Mini Die Grinder||4.6|
|Ratchet – 1/4″||2.5-3.5|
|Ratchet – 3/8″||4.5-5|