Industrial Utility Efficiency    

System Assessment

“Retro-Commissioning” (ReCX) of compressed air systems has become a trendy activity with many utility demand-side-management programs emerging in the last 5-10 years.  This is intended to be the process of “tuning up” a compressed air system, getting low cost savings from mostly adjustments and repairs.  The term was borrowed from the building/HVAC industry, where it means to get a system operating as it was originally “commissioned”. 

Compressor Controls

UniFirst is one of North America’s largest workwear and textile service companies. They outfit nearly two million workers in clean uniforms and protective clothing each workday. Founded in an eight-stall garage in 1936, the Company has grown to 240 customer servicing locations throughout the U.S. and Canada servicing 300,000 business customer locations. The subject of this article is an energy-saving Air Demand Analysis (ADA), conducted by Kaeser Compressors, at UniFirst’s centralized 320,000 square foot hub Distribution Center located in Owensboro, Kentucky.

Piping Storage

Technology is available which enables a compressed air flow meter to measure not only the magnitude of the flow, but also the direction. Why is this important? In this article we will describe two case studies where bi-directional compressed air flow measurement plays a key role to come to the right conclusions. In the first case study, we will describe an electronics manufacturing plant, which has a large interconnected ring network with two air compressor rooms located in different buildings. The two air compressor rooms are about five hundred feet apart. In the second case study, the effect of compressed air flow measurement upstream of a local receiver tank is described.

End Uses

At a Midwest window manufacturing plant, the cooling process for the plastic frame pieces, after leaving the extruder, was critical to process productivity and quality. Too much cooling air (or not enough cooling air) would generate scrap and rejected product. The plants’ 17 extruders and 55 separate blow-offs in these lines had similar cooling stations at the cooling boxes. They consisted of about three hoses at each exit frame angled down to the extruded piece moving past it. The compressed air flow was controlled by a manual control valve set by an operator. The operator used his experience to control the flow delivered and thereby control the product quality.


A Canadian chemical plant installed a large heated blower-purge style compressed air dryer, years ago, to condition the instrument air system against freezing temperatures.  The dryer selected was oversized for the connected air compressors and had unused on-board energy savings features.  A compressed air assessment revealed the site air compressors and compressed air dryers were running inefficiently and causing in-plant pressure problems.  Repairs to a compressed air dryer and the replacement of aging air compressors and dryers has reduced compressed air energy costs by 31 percent.

Air Treatment/N2

A pharmaceutical product manufacturer spends an estimated $137,443 annually on electricity to operate the oil-free air compressors in its compressed air system. The compressed air system operates well and is providing the level of purification required.  Our team visited the plant and identified a group of projects which could reduce compressed air demand and reduce energy costs by $42,248 – or 31% of current use.


Compressed air optimization measures adopted by PTMSB have reduced the consumption of compressed air by 31 percent resulting in savings of about 3,761,000 kWh per year in energy consumption. The monetary savings are MYR 1,090,627 per year ($255,000 USD). The CO2 reduction is estimated at 2,735 ton per year.


Energy, in all forms, has always been a key Lantech focus. It was, in fact, a key element of the core packaging problem the company’s founders set out to address. They saw an opportunity to capitalize on an inexpensive and under-used resource – stretch film – to displace a high materials cost and energy intensive way of unitizing pallet loads of products – shrink bagging.

Vacuum Blowers

Every municipality and utility is facing the reality of rising energy costs. In 2010, the Town of Billerica, MA, which is located 22 miles northwest of Boston with a population of just under 40,000 residents, engaged Process Energy Services and Woodard & Curran to conduct an energy evaluation of the Town’s Wastewater Treatment Facility (WWTF) and pump station systems sponsored by National Grid. The objective of the evaluation was to provide an overview of each facility system to determine how electrical energy and natural gas were being used at the facility and to identify and develop potential costsaving projects.
Sometime in mid-2015, I received a call from a project engineer at a major plastics firm. He had a troubling issue with one of his PET bottle plants. The bottom line was this: They could not run all five high production blow-molding machines at one time—even though they were able to do so 18 months previously.
Air-operated double diaphragm (AODD) pumps are common to many manufacturing facilities. As estimated by veteran compressed air auditor Hank van Ormer of Air Power USA, approximately 85 to 90 percent of plants in the United States have AODD pumps. They are used for all kinds of liquid transfer applications, like those found in chemical manufacturing, wastewater removal, and pumping viscous food products.
There is always something new to learn about compressed air systems – particularly in regards to compressed air dryer installations. As I discussed in Part 1 of this series, you can make compressed air dryer installations more reliable by understanding the consequences of any modifications you make to the system.  As a continuation of those ideas, Part II explores more ways to make a dryer installation more reliable. Discussions include: the difference between operating a desiccant dryer in a fixed cycle opposed to demand mode, what happens when you operate a heated desiccant dryer with the cooling air turned off, and how to deal with the unintended consequences of dedicating a desiccant dryer to a compressor. 
One of the statements made in the Compressed Air Challenge’s Fundamentals of Compressed Air Systems seminar is that improvements can always be made to every compressed air system, including new ones. The statement definitely applies to a Canadian pork processing facility built a few years ago. This article is based on a compressed air audit performed two years into the life of a brand new plant. The audit found numerous problems and made recommendations that helped reduce plant compressed air operating costs by 60 percent. 
Compressed air is used in more than 70 percent of all manufacturing activities, ranging from highly critical applications that may impact product quality to general “shop” uses. When compressed air is used in the production of pharmaceuticals, food, beverages, medical devices, and other products, there seems to be confusion on what testing needs to be performed.
In compressed air systems, every adjustment or system modification has consequences, so, before making changes, it’s important to understand how those changes will affect each piece of equipment.  For example, simple things — such as lowering the compressor’s pressure set point, or failing to maintain the compressor’s aftercooler — can result in moisture contamination occurring out in the system. Why? Because the effects of these actions reduce the air dryer’s capacity. In this article, I address some ideas that can make your system more reliable.
Ahresty Wilmington Corporation (AWC) was founded in 1988 and is located in Wilmington, Ohio. Currently AWC employs over 900 people with sales totaling $192 million. They have grown steadily, all while continuously improving and staying on the leading edge of technology. AWC is a tier-1 automotive supplier servicing their entire customer base in the United States. AWC has established an efficient and integrated production system that incorporates die-casting, finishing, machining, and assembly operation using just-in-time production methods to provide its customers with quality products at a competitive price.
In recent years, we have seen an upward trend of higher production manufacturers wanting to integrate their air gauging quality checks from a stand-alone, outside-of-machine device where the operator is performing a manual check to an automated in-process gauge. There are several reasons for this trend, including higher quality standards, tighter tolerances, as well as running a leaner operation. The benefits are 100 percent inspection of the required geometric callout, as well as handshaking between measuring device and machine to make each piece better than the prior one. It also removes any bad parts.
When a company is considering making an investment of more than a million dollars in system upgrades, it is crucial for them to review all options to get the best return. By exploring energy efficiency impacts throughout the entire compressed air system, vendors can propose projects resulting in both a larger sale for them and increased financial benefits for their customers, while still meeting capital expenditure guidelines. This “best of both worlds” scenario was evident when a foundry in the Midwest was evaluating options for replacing its steam system used to drive the plant’s forging hammers.
EnSave, an energy auditing company based in Richmond, Vermont, recently performed compressed air audits at two facilities of a leading U.S. steel manufacturer. Both plants are mills that melt, cast, and roll steel to produce a variety of products, including: rebar, merchant bar, steel flats, rounds, fence posts, channel bar, steel channels, steel angles, structural angles and structural channels. These products are used in a diverse group of markets, including: construction, energy, transportation and agriculture. Compressed air is provided at 100 psig in both plants for a variety of applications — from optical sensor cooling to pneumatic cylinders for stacking finished products.