Posts Tagged ‘cfm delivered by compressor’

Here’s one of the most used formulas you should keep on hand…
How to find how many CFM your air compressor delivers.

Follow these steps to find how many
CFM Your Air Compressor delivers

1. STOP the compressor unit

2. CLOSE the outlet valve on the tank/air receiver

3. DRAIN the condensate from air receiver until there is 0 PSIG -then close the drain valve

4. NOTE THE TIME– minute & second. Then START THE UNIT.
When unit stops/unloads – then NOTE THE TIME again – minute & seconds. Convert minutes into seconds and then total number of seconds it takes between START and STOP/UNLOAD.

5. NOTE the GUAGE PSIG reading

6. NOTE the Air Receiver/Tank GALLON SIZE


TANK GALLONS x .538* x PSIG divided by SECONDS
You have an 80 gallon tank, your total seconds timed were 189 and you noted 175 PSIG.

80 multiplied by .536 = 42.88
42.88 multiplied by 175 (example PSIG) = 7504.00
7504.00 divided by 189 (total seconds)= 39.71 CFM delivered

You now know that your air compressor is delivering 39.71 CFM

Your Response to this evaluation should be to compare this number with what your air compressor manufacturer says your CFM should be and evaluate how efficiently your compressor is running.

Tommy McGuire

McGuire Air Compressors, Inc.
“Real People with Real Compressor Experience”