System Assessments

This chemical plant spent an estimated \$3,153,022 annually on energy (steam and electricity) to operate the compressed air system at their facility. The plant staff established their energy costs as 5.3 cents per kWh and \$9.00 /1,000 lbs of steam per hour. The set of projects implemented in this system assessment reduced energy costs by an estimated \$2,794,598 or 88% of current use. In addition, these projects reduce demand on the boiler systems and add reliability and back-up to the compressed air system.

Keeping an open mind is critical in all system assessments. Each client has different priorities and circumstances. In this case, the elimination of the “close-scrapes” with insufficient pressure was the priority. The energy and rental/maintenance savings realized were just an added bonus. In this article, we have focused on the supply-side of the system and how the centrifugal compressors could be made to supply the system reliably – without the need for rental air compressors.

This food industry factory, located in California, was spending \$386,533 annually on energy to operate their compressed air system. This system assessment detailed eleven (11) project areas where yearly energy savings totaling \$154,372 could be found with a investment of \$289,540. A local utility energy incentive, paying 9 cents/kWh, provided the factory with an incentive award of \$159,778. This reduced the investment to \$129,762 and provided a simple ROI of ten months on the project.

Over the years, analyzing compressed air system operation and efficiency has gone under various names and taken many different shapes and forms. You may know these as; Assessments, Audits, Studies, and Surveys, but in all cases the compressed systems are analyzed using techniques, such as metering and measuring, to assess the system’s performance and identify opportunities for improvement. The problem is that the results of these activities have varied widely; leaving the end-user to try and determine what is usable, credible and implementable. This has led to a lot of “no actions“, resulting in assessments, audits, studies, and surveys being put on the shelf to collect dust.

A plastics molding plant had engaged us to conduct an ‘on-site’ Energy Assessment of their facility. The annual ‘spend’ for electricity, natural gas, and water was about \$3.2 million for this modern 275,000 square foot, fully air-conditioned facility. During the Review, several opportunities were identified and delineated in lighting, HVAC, process ventilation, the water systems and energy supply contracts. However, the most significant savings were in their compressed air system.

A couple of key principles must be considered if we want to understand and control the operating costs of your compressed air system. First, compressors pump air, they do not make pressure. The system creates the back pressure which the compressors must pump against. When the compressor delivers more air than the demand requires, the pressure rises and of course, the reverse is also true. Secondly, any component or application which forces the pressure to be higher than necessary creates wasted energy in the system. This waste is not linear to the increase in pressure but can be exponential for many reasons. However, the main contributors are artificial demand and the size of the compressors in the system.

So you need nitrogen in your plant! In a high percentage of cases, generating your own nitrogen using commercially available equipment is a very cost effective alternative to purchasing liquid nitrogen or cylinder nitrogen from traditional supply sources like the industrial gas companies. In some cases, the return on investment (ROI) ranges from six months to 2 years, but ROI can range, depending on several factors, to several years while still being a good investment. With rising fuel and energy costs, the cost of liquid nitrogen is going up and is making it much easier to justify the purchase of a nitrogen generator in a wide range of purities and pressures.

Treating compressed air as a true utility and outsourcing the entire process is a growing trend in the industry. If a plant does not generate their own power, provide their own water or deliver their own natural gas, then why not treat compressed air requirements in the same manner? This article will use a recent project as a case study to show the benefits one factory received by making the decision to outsource compressed air like a utility.

International Wire Group, Inc. (IWG) headquartered in Camden, NY is the largest bare copper wire and copper wire products manufacturer in the United States with expanding operations in Europe. Products include a broad line of copper wire configurations and gauges with a variety of electrical and conductive characteristics , which are utilized by a wide variety of customers primarily in the industrial and energy, electronics, data communications, aerospace and defense, medical electronics and devices, automotive, and consumer and appliance industries.

This facility is part of a corporation producing molded plastic products. There are many injection and extrusion molding processes. The factory was spending \$94,934 annually on energy to operate their compressed air system. This system assessment detailed seven (7) project areas where yearly energy savings totaling \$53,191 could be found with a minimal investment of \$4,170.