Compressed air is one of the most misunderstood utilities in industry. Case in point, Yesterday I overheard a conversation at a hardware shop between a customer and a sales person. "I would like a compressor, 200 liters". Stated the customer. The attendant checked to see if such a compressor was available and proceeded to give a price. The customer then asked " What is the compressor motor HP?". The seller did not know and had to confirm the details. This conversation may not seem out of place if you are not a a compressor professional but to those in the industry it sets alarm bells ringing. This conversation leaves out the most crucial information about sizing and selecting a suitable compressor.
What is the application?The application will guide the air quality requirements eg. the need for a dryer, filters or an oil free compressor. The application will also guide the choice of compressor type. With screw compressors more suitable for continuous operations such as those in manufacturing and piston for intermittent use such as petrol stations or workshops.
What are the pressure and flow requirements? This would be the equivalent of the load the compressor is expected to serve and is the most important information in determining the appropriate size of compressor. This information can be found by checking the data plates of the equipment that will be using the air or by carrying out flow and pressure measurements.
Back to the customer that I listened to; its possible that he may have found a solution to his application. It is also possible that he procured an item that was oversized or undersized both of which are undesirable. Compressors are now available over the counter at many hardware shops. This shifts the responsibility to the customer to understand his application well enough to know what his requirements are. On the other hand, if the vendor is informed then he can advise his customer accordingly. However if both are uninformed it's the perfect recipe for expensive mistakes.
This encounter raises the following questions: Are we are as informed about compressed air as we believe? What energy efficiency opportunities are we missing due lack of information? Have we invested in compressed air Training?