Industrial Utility Efficiency    

Air Compressors

In general, this article focuses on the definitions of terms often used to understand centrifugal air compressor performance. Comments are also made on how to measure power consumption. This article is not intended to be an engineering discussion of the various types and designs of centrifugal and other air compressors.
Since the cost of energy has dramatically increased during the past few years, it seems that energy audit companies have opened shop on more city street corners than coffee shops in Seattle.  In addition to the mass numbers and abundant varieties of these energy savings promoters, there have been an equal number of energy audit articles written for the engineering magazines.  
In the U.S. as an example, the NFPA has taken the view that if your compressor draws in good clean ambient air, the air stays clean through the compressor, is then dried and filtered, when you deliver it to the patient it will be entirely satisfactory. After all, when you went into the hospital that’s what you were breathing and when you leave you will breathe it again!
Located in the bowels of most hospitals, you will find the source of the Level 1 Medical Air compressed air system. Per the NFPA Section 99 Specification (National Fire Protection Association), Level 1 air compressor systems provide air for human consumption within the hospital facility.
Roxane Laboratories, Inc., a subsidiary of Boehringer Ingelheim Corporation located in Columbus, Ohio, created a world-class air system that generated $61,314 per year in electrical energy cost savings (1,156,868 kWh), improved productivity and quality, and allowed the successful completion of a significant plant expansion.
This aluminum mill spends $369,000 annually in energy costs to operate their compressed air system. This system assessment recommends actions reducing annual energy costs by $120,000 and improving productivity and quality by delivering clean, dry compressed air.
A paper mill in Wisconsin reduced its’ yearly water consumption by 547.5 million gallons and reduced its’ yearly air compressor maintenance costs by $470,000.  
This article reviews two major processes in paper mills: compressed air quality and air compressor cooling.  The central air compressor room was expanded and relocated at the largest privately owned paper mill in Canada.  The compressor space was required by a plant expansion, which would occupy the original compressor space for increased production.
Compressed Air Best Practices® interviewed Mr. Sid Van der Meer and Mr. Terry Nickel from Northwest Equipment Ltd in Airdrie, Canada.
There are many applications which require a low horsepower compressor built with the technology that has been proven in larger compressors. Often these situations are not addressed well by the general compressor industry.  
This factory currently spends $735,757 annually on the electricity required to operate the compressed air system at its plant. The group of projects recommended in the system assessment will reduce these energy costs by an estimated $364,211 (49% of current use). Estimated costs for completing the recommended projects total $435,800. This figure represents a simple payback period of 14.4 months.