I hope this information has been useful to you

Air output of a compressor is expressed in standard cubic feet per minute (SCFM) or just cubic feet per minute (CFM). Not all 5 HP compressors put out the same volume of air per minute. This is a function not only of motor horsepower but also the efficiency of the air compressor pump the motor is powering. The higher the CFM, the less your air compressor will have to cycle on and off to keep up with the demands you are putting on it. A small compressor pump on a huge tank will produce no more air than on a small tank. The only difference will be in the number of times the compressor cycles on an off each hour and the time it takes to recompress the tank on each cycle. In the final analysis, you need to pay attention to SCFM (or CFM) more than you do motor horsepower or tank size. Air flow is the end product of any compressor and the CFM must be sufficient to the job at hand.

All reciprocating air compressors throw out some oil with the air they compress. When the tank reaches it’s designed pressure limit, a switch will interrupt electrical power to the motor. Simultaneously, a certain amount of oily air will be Heat Pump Unit released into the shop environment. You may see oil collecting on the wall behind the compressor and on the pump and compressor as well over time. This is not cause for alarm but periodic cleaning may be needed.

Reciprocating (piston type) air compressors are noisy and this is something you need to anticipate for the sake of yourself, your workers and others who are in the neighborhood. If quiet is an important consideration, you may want to think about spending the extra money for a screw-type air compressor. Screw-type compressors have no pistons or cylinders. Air is compressed in turbine fashion by a large metal screw, turning at a very high speed. These machines just purr compared to the reciprocating type but they are very costly. They sound more like a quiet jet engine than a loud truck motor.

I hope this information has been useful to you. Buying an air compressor for your woodworking shop can be a fairly expensive investment when you consider piping, regulators, hoses, water traps, wiring and electricians. You will want to buy a compressor that is capable of the tasks you will be using it for but no more than that. Purchasing the wrong air compressor can be a very expensive mistake. My motivation in writing this has been to give you the knowledge you will need to select the right one.