Inappropriate-Use Assessment Saves 1,881 scfm
Compressed Air Best Practices, January 2010

Brewery operation located in the Midwest spent $735,757/year in electric energy cost to operate its compressed air system. The supply side and production side assessment reduced the cost by $364,211/year (49%). Total project costs of $435,800/year which generates a simple payback period of 14.4 months. The plant was using 5,000 to 6,000 cfm with 3 to 4 centrifugal compressors on-line and appropriate blower purge dryers. The supply side efficiency was improved 25% by replacing the oldest, least efficient centrifugal with a new, more efficient, higher turndown unit and some capacity control modifications. Further direct energy reduction was accomplished by replacing the blower purge dryers with heat-of-compression type. Addressing inappropriate uses such as tagging and repair of compressed air leaks, adding auto shut offs to reduce some significant compressed air utilization (from 80% to 30%), blow off air modification, modifying of the pneumatics air booster, all accounted for 5,870,564 kWh reduction and 1,881 scfm less compressed air demand.

Food Packaging Factory Saves $154,000 in Annual Energy Costs
Compressed Air Best Practices, April 2012

A complete supply and demand-side audit of a California food packaging plant reduces the $386,533 annual electric operating cost by $154,372/year (31%). The $280,540 initial cost was offset by a $159,778 utility ratepayer rebate orchestrated with Air Power USA support for a simple payback of 10 months. Major compressed air reduction projects included leak identification and repair, blow-off, agitation, and cabinet cooling modifications. The supply side also required modification to enable the compressors to effectively translate less system compressed air use into a commensurate amount of lower input electric energy.

Food Processing System Assessment of the Month
Compressed Air Best Practices, April 2009

A cereal and power bar North American facility processes bulk food ingredients into finished packaged food products. Annual electrical energy cost to operate the compressed air system was $733,347/year. The full assessment detailed 12 projects generating an annual electrical energy savings of $214,907/year (29%) with an overall investment cost of $68,350/year (2,549,700 kWh reduction) – a simple payback of 3.8 months. The projects varied from supply side improvements improving the specific power (scfm/kW) of the air supply about 5%. Additional direct savings came from dryer operating efficiency improvements, lowering system header pressure 5 psig, and shutting off several unnecessary air compressors and dryers throughout the production area. A series of compressed air reduction projects eliminated 1,124 scfm of compressed air demand.

Prepared Food Plant Manages Leaks and Blow Offs
Compressed Air Best Practices, October 2010

This Midwestern prepared food facility produces prepared foods which are frozen and then shipped for distribution. The production is vertical as meals are cooked and prepared onsite. The annual electrical energy bill was $269,463 to operate the compressed air system. The assessment projects generated an annual electric savings of $112,902 (41%). The total cost for all projects $146,102 which represents a simple payback of 15.6 months. Demand side projects such as tag and repair leaks, reconfigure cabinet coolers, add Venturi flow amplifiers to open blows, replace air vibrators with electric type, remove unnecessary cooling air on motors in palletizing, and replace high pressure air used for agitations with low pressure blower supplied air, all reduced the total production air demand by 891 cfm. Modifying the compressor room piping and compressor capacity controls allowed the compressed use reduction to reduce the electric input a commensurate amount.

Food Processor and Packaging System Assessment of the Month
Food Processor Saves $101,000
Compressed Air Best Practices, October 2012

This article references a facility that processes and packages food product for shipment to retail outlets. The plant annual electric energy cost was $210,000. The projects in the assessment identified $100,855 annual energy savings (48%) with an implementation cost of $100,000 for a simple payback of 12 months. A 10% improvement in the air compressor operating specific power (scfm/kW) was accomplished with appropriate piping and capacity control modifications. These same projects allowed the reduction in production compressed air use of 1,051 cfm to show result in a significant reduction of input electric energy.

North America, Chicago Cereal Plant Saves $51,981 per Year

Comprehensive study of the total compressed air system at a North America breakfast cereal and snack manufacturer saves $51,981 per year in electric energy operating costs with a $19,624 total implementation cost offset by a $15,129 utility rebate – simple payback in less than 5 months. A news release by ComEd, the Exelon Company sponsoring utility, provides details of which Air airpowerusainc.com 3 Power USA performed the compressed air system review, pre-project measurement and supervised all project implementations working with site plant personnel. Verification and post-measurement were performed by a third party.

Plastic Injection Molder Saves $53,000
Compressed Air Best Practices, March 2012

Midwestern facility which produces plastic injection molded products of many different designs and specifications. The plants’ annual electric cost to operate the compressed air system was $94,934. The assessment identified 7 projects which generated an annual operating energy cost reduction of $53,101 (56%) with an implementation cost of $4,170 for a simple payback of about 1 month. Small but critical piping changes in the compressor room along with readjustment of the compressor capacity controls led to a specific power improvement of 20% (scfm/kW). This also allowed a 315 cfm of compressed air reduction in production air usage to result in a commensurate lower input electric energy.

Plastic Extruder Saves $116,000 in Energy Costs
Compressed Air Best Practices, April 2013

Plastic extrusion factory where the plant’s high-quality rotary screw compressors supplied the plant with 994 acfm of compressed air. The audit focused on the compressed air applications and reduced plant demand to 453 acfm. Forty-six leaks (worth 174 cfm) were found in the pneumatic circuits on production machinery. Eighty-four “open-blow” applications on production equipment were replaced with Venturi inducer nozzles — saving another 320 cfm. Focusing on the applications helped the customer reduce air compressor annual energy consumption by 67%! The demand side projects created $116,520/year in annual electrical energy cost with a total project implementation cost of $20,100.

Steel Processing Compressed Air Audit of the Month
Compressed Air Best Practices – Nov/Dec 2008

Midwest U.S. plant is one of the nation’s largest steel plants and is over 100 years old. The processes involved in the assessment were Bar Mill, Roll Mill , Hot Strip Mill, Electric Galvanizing, Slab Yard, Green Coil, Pickling, Cold Mill, Annealing, Coil Distribution and Shipping. The total annual electric cost to run the compressed air supply for this facility was $1,516,000. The identified and implemented projects generated an annual energy savings of $855,000 leaving a net electric operating cost of $660,000. Total cost of the projects fully implemented was $307,150, leaving a short payback of 4 to 5 months. There was a measured air flow reduction of 11,500 cfm which also avoided the purchase of a replacement 7,000 cfm/100 psig centrifugal. Before the assessment a 7,000 cfm/100 psig centrifugal suffered a major failure and the decision was made not to invest the money to replace it and consider upgrading the supply side equipment. After the failure of this unit, additional rentals were brought in until the replacement equipment was obtained. Plant management thought that before they upgraded the air supply to a new level, a study should be implemented to answer several questions:

• • What are the underlying causes of this continuing increase in compressed air demand?
• • If this is wasted compressed air with no subsequent improvement in production or quality, what is the bottom line incremental energy cost to the company?
• • What action can be implemented to eliminate this air demand? What is the cost of the action? What is the return?

The assessment answered all these questions and the recommended compressed air reduction projects reduced the actual flow demand back to former levels eliminating the need for a replacement 1,750-hp centrifugal compressor. The most significant compressed air reduction projects were: blow off air optimization and control, air horn removals and limitation, leak identification and repair, optimizing compressed air drying, and system flow monitoring at critical points to preclude growing again.

Aluminum Mill Reconfigures Compressed Air System
Compressed Air Best Practices – April 2010

This northwest aluminum rolling mill spends $369,000 annually in electric energy cost to operate the compressed air system. The system assessment reduced this annual electric energy cost by $120,000 (30%). The plant had grown over time and the air supply was from three separate compressor rooms (Hot Mill, Re-Melt and Cold Mill). The interconnecting piping and compressor operating profile were modified to eliminate high air velocity driven backpressure and flow resistance. This allowed the 7,000 scfm required flow to be delivered when only operating the Hot Mill room (with one less compressor) and moving the Re-Melt room and the Cold room units into permanent backup emergency use. Large heated desiccant dryers were moved into backup and an energy savings heat-of-compression dryer was mated with the oil-free centrifugal to deliver proper quality air to the Mill. This action combined with effective compressed air reduction projects led to a very successful result.

Ohio Aluminum Industries Compressed Air System Improvement Projects Saves Energy and Improves Product Quality
US Department of Energy, Best Practice Case Study

Ohio Aluminum Industries in Cleveland, Ohio, working with the US Department of energy and its allied partner Air Power USA, Inc. implemented the projects identified in the compressed air system review. The total project yielded $73,200 in direct annual electric energy savings with a total implementation cost of $83,000.

Ohio Aluminum Industries produces a wide range of precision aluminum components for the defense, aerospace, aircraft and automotive industry. It is a vertical manufacturing process which includes green sand molding; clay sand molding and permanent and semi-permanent molding.

The main projects realigned the compressed air supply, interconnecting distribution piping configuration and process controls. The systems stability improved the very critical core machines performance.

Auto Manufacturer Eliminates Dryer Purge Air
Compressed Air Best Practices – Nov/Dec 2008

This northeastern U.S. automotive manufacturing facility spends $269,046/year to run the compressed air system even at a very low electric power rate of 1.9 cents/kWh (.019 kWh). The projects from this assessment reduce these energy costs by $110,166/year or 40%. The primary focus of the review was not only energy costs but reliability of the compressed air quality as well. It is mandatory that air does not exceed the -40ºF pressure dewpoint limitation. The projects accomplish this while reducing the overall compressed air demand by almost 4,000 scfm (1,000-hp). Post-measurement up to six years later have shown a constant pressure dewpoint never above -40ºF and the equipment monitoring devices in place have also shown all the savings still intact with a ±4% on projected to actual specific power.

Tier 1 Automotive Plant Saves $218,000 in Energy Costs
Compressed Air Best Practices – March 2011

A Tier 1 automotive parts plant was spending $364,259/year on electric energy to operate the compressed air system at 7.16 cents/kWh (.0716 kWh). This full system assessment (supply and production side) reduced this cost by $218,670/year or 60%. These projects also allowed the plant to have much needed backup of all its compressor rooms. Simple payback was 13 months. The plant had all their supply spread out over five different locations and ran all the compressors all the time yet “did not have enough air”. Each room entered the main distribution header at different locations making it very difficult to control or for the operating personnel to know what was actually happening. The basic work was to measure with a flow meter, kW meter and pressure transducers, and appropriate data logging equipment exactly what each unit was doing simultaneously. This data revealed which units were needed and which were not; which units were receiving false signals for control and where those signals were coming from. Continued analysis allowed the plant to make inexpensive changes to compressor and dryer alignments and reduce the overall air demand over 500 cfm and the annual operating electric energy cost over $70,000/year. Follow-up sustainability programs have continued to improve the operating efficiencies.