Enhancing Plant Profitability and Sustainability

Rod Smith key note address 2018 Best Practices Expo. Learn how the compressed air industry has learned how to you can learn how to learn less through the best practices shared by industry experts.

How Valuable is a Free Air System Audit?

Free Compressed Air Audit vs. Permanent Monitoring: What is your best option?

Optimal compressed air system performance, defined by efficiency, reliability and air quality, has now become the main goal when operating, installing, purchasing or designing compressed air products. Whether you are the air compressor manufacturer, distributor or end user – everyone in the compressed air industry needs to be aware and work towards these goals.

Baselines Developed by Permanent Monitoring vs. Temporary Compressed Air Audits

Rapidly rising energy costs, tough economic times and the need to reduce costs are factors impacting all businesses operations. This is driving a wave of demand for energy reduction measures and technologies. Compressed air systems, a very expensive utility, have become the first target for energy reduction measures in most industrial facilities today.

“Free” sales-based audits have become readily available, in the compressed air industry, from many organizations pushing product sales.  How reliable are the results and recommendations from these free audits lasting a maximum of ten days? What is the actual value to the bottom line for an end user?  These are the questions typically raised surrounding free audits. Since free doesn’t exist, what’s the catch? Do factories have another option? Yes, they do.

Airleader is heavily involved in compressed air audits, working with several utilities in the United States and in other countries around the world. For larger compressed air systems, we recommend the utility providers spend the extra incentive money to invest in a permanent monitoring system – rather than ten days of temporary metering for an audit. A permanent monitoring system can provide a very solid baseline, developed over several weeks or months. It also allows one to examine and quantify various metrics such as weekend leak rates, and different loads based on many more production day profiles. Creating a more robust baseline profile allows an audit to better identify several corrective measures such as storage, piping changes, control systems or leak repair – and precisely quantifying the ROI for each measure and prioritizing them with budgets or timelines.

An Audit Process Using Two Months of Data

We recently performed a compressed air audit at a large manufacturing facility running several large air compressors at two separate locations in the plant. Metering equipment was installed including kW meters, flow meters and pressure sensors throughout the facility. A thorough leak audit for the whole facility was also performed. The audit process took just under two months to collect the data, find the system inefficiencies and make the proper recommendations.

The compressed air audit report was presented to the client identifying substantial inefficiencies due to poor piping, improper control of the air compressors, excessive unloaded compressor times, huge amounts of air leaks, and to everyone’s surprise, the discovery that the system runs on two different pressures as the systems are separated via underground piping networks. As one can imagine, getting to the bottom of a system like this was going to be a massive undertaking. It would need to be done in stages, using a tremendous amount of instrumentation.

The first measure had to be a master controller. With the master controller, we would then be able to control the compressors and correlate the data collected to production demands and leak loads.  Stage one included the master controller, large air receivers, a large energy efficient compressed air dryer and a large VFD air compressor to trim the base loaded units. Once the system was installed the savings were immediate, unloaded air compressor power went from 70% to 15% while decreasing the motor cycles – saving the motor and bearing life of the air compressors.


Metering and Monitoring of Compressed Air Flow – Click here to enlarge.

Five Months After the Audit

With proper control of the compressed air system now in hand, we began the task of identifying further measures through the data collection system and permanent metering installed. This quickly identified a leak rate >50%, which on a system consuming more than 10,000 cfm at times, is a massive volume of leaks. We identified the leak rate by correlating flow rates during down-time on Sundays and Saturday off shifts. This data was compared to the data from the kW meters (on the air compressors) which allowed us to build a proper ROI for the client. Without the permanent metering, we would have had no way of accomplishing this task.  The plant, however, needed to understand the data to believe in the project.

I remember coming back to the site, five months after the audit, to do some customer training on the master controller. Just as I getting ready to leave, I was told I had to wait for their system analyst to come down. I asked the maintenance manager, “What analyst?” He responded saying the analyst was from the accounting department but he didn’t know what the analyst wanted. Soon the gentleman arrived, carrying some printed graphs from the monitoring system, similar to graph 1. He asked me, “Can I trust the data provided from your system?” I looked at the data and said, “Yes you can, why do you ask?”

The analyst was shocked that on Sundays, when the plant was closed, the flow rate was 3500 CFM and even more shocked when he realized that the plant leaks the same amount 365 days a year. The next question from the Analyst was, “How can you confirm this is the correct flow rate?” I then used the kW data, to show that yes, three air compressors were running loaded – again confirming the leak rates were correct.


Table 1: Air Compressor Performance during a full week – Click here to enlarge.

We printed the weekly performance table (table 1) and a weekend day performance table (table 2), allowing us to perform the following calculations.

Leakage = 16,789 kWh (Saturday to Friday) = 117,523 kWh / week

Total Air Demand (Saturday to Friday) = 206,666 kWh/ week

    • 56.9% of compressed air is lost through leaks
    • At 10 cents/kWh = leaks represent US $611,120 annually


Table 2: Air Compressor Performance during the weekend – Click here to enlarge.

Within a few weeks of our conversation, a plan was in place to install multiple flow meters and pressure sensors throughout the facility to find the losses in the vast piping network. Identifying the leak losses of 6.1 million kWh triggered the immediate installation of the sensors, which through the webserver software on the master controller, allowed the client to identify the areas of the plant that should be targeted for leak repair first. Using the tools now available to the Client, a long-term leak prevention strategy is in place by setting limits to the flow across the flow meters triggering an email or alarm if the flow (CFM) should start to climb beyond the existing “best practice” values.


Being involved in hundreds of audits of facilities, like the one described, we see the same thing repeatedly. Typically a free audit is performed and a large VFD air compressor is installed. The client carries on with production never realizing what’s going on with the system. Installing a VFD air compressor is a supply side addition, which may or may not generate savings, depending on how it is sized and applied.

A new VFD air compressor  doesn’t change the demand side of the compressed air system – where the air is being used and/or wasted.  The new VFD air compressor may help supply the compressed air leaks and inefficiencies at a better specific power – but it will not rectify the issues still present within the system. Opting for a more expensive, but much more detailed audit of the entire compressed air system is the only way to find these kinds of savings. Combining this type of audit with permanent metering and monitoring is a long-term sustainable solution and not just a way to purchase a new air compressor.

Permanent metering and monitoring will also provide a continuous 24/7 audit helping to sustain the savings – after compressed air system improvements are made. This provides the plant the tools to adhere to ISO 500001 energy guidelines, provide the data for utility incentives without the costs of a post-audit, as well as justify the ROI to carry out any future efficiency upgrades.


“You cannot manage what you do not measure.”

This article was published in Compressed Air Best Practices. To read the original article or similar Air Compressor System Assessment articles, visit: https://www.airbestpractices.com






World Energy Engineering Congress

Jan Hoetzel Managing Partner AirleaderJan Hoetzel, managing partner of Airleader will present “Benefits of Continuous Monitoring for Compressed Air Systems” at World Energy Engineering Congress in Charlotte, NC October 18, 2018. WEEC is the largest energy conference and technology expo held in the U.S. specifically for business, industrial and institutional energy users. The conference brings together the top experts in all areas of the field to help businesses set a clear, optimum path to energy efficiency, facility optimization and sustainability.

More information about the conference may be found at http://www.energycongress.com

Airleader Chicago Heights Steel

Airleader Saves Chicago Heights Steel 2.5 million kWh annually

Airleader Chicago Heights Steel

Chicago Heights Steel receives ComEd rebate


Airleader performed a complimentary leak study and leak repair. The service provider knew there were much greater energy savings to harvest through system improvements and persuaded a reluctant management to install a Master Controller to continuously monitor the system during operating hours and down time. By monitoring and analyzing key performance indicators with the Master Controller, improvements to increase the efficiency of the system were identified then verified. The project resulted in an overall decrease of 2,582,979 kWh annually or $215,037 at current rates. Additionally, the mill received a utility rebate in the amount of $177,714 which resulted in a simple Return on Investment of 0.2 years.

Airleader CHS Project Stats
The Project

Many industrial customers are frustrated with the high costs of their compressed air systems. Airleader was the third service provider contacted and performed a leak study and leak repair. The previous attempts were incomplete. Airleader provided a complimentary leak test and repair for the customer. After the complimentary leak repair the customer was not motivated to move forward with further measures doubting the savings would be worth the investment.

Airleader, on the other hand, knew there were much greater energy savings to harvest through system improvements and persuaded the customer to install a Master Controller to continuously monitor the system during operating hours and down time.

The System

The existing air system consisted of two compressor rooms which were not connected. There were three compressors in each room and two different system pressures. There were two desiccant dryers. The system was being manually controlled with 5 out of 6 compressors running in modulation.

The Pilot Audit/Permanent Monitoring System

Airleader Master Controller and Monitoring was set up providing continuous, online data logging during production and during down time. kW meters were placed on each compressor. Flow meters and Dew Point sensors were placed after each compressor room.

Airleader Compressor Room Layout

Compressor Room Layout

Permanent Monitoring

Data was collected on the system from December 2015 – February 2016 (1) to provide a baseline and a snap shot of the system. During February leaks were repaired. The first month of leak repair savings were harvested by the company in March (2). Airleader connected temporarily to one compressor room to verify saving potential (3). The next step was to replace the desiccant dryers with cycling dryers. (4) resulting in further savings.

The last week in December, the Airleader Master Controller was connected to the system. Maintenance was given access to online monitoring. A 4” pipe connecting the two compressor rooms was opened. Dramatic energy savings were achieved through system improvements (5). Because of the significant savings, the customer was able to invest new compressors to replace the compressors which were older than 20 years and not as reliable. A 200HP and 75HP VSD were installed as well as a 150HP fixed drive. Performance suffers based on 5-7% premium energy demand of the VSDs.

Airleader Compressor Energy Savings

Energy Savings Resulting from Project Improvements

Project Results

This project resulted in an overall decrease of 2,582,979 kWh or $215,037 which the customer will harvest annually. The total project costs for installing permanent monitoring and Master Controller, upgrades to system piping, storage and compressors were $240,139. The company received a $177,714 utility incentive. The project had a simple ROI of 0.2 year after utility incentives.

The key takeaway of this project is that the opportunities for improvements would not have been discovered without permanent monitoring in place. The case study demonstrates permanent monitoring of the compressed air system is a best practice resulting in annual savings. It provides key system data which is useful for system troubleshooting and discovering additional system efficiency which may be gained.


ComEd Chicago Heights Steel Case Study


The new Airleader WebServer is available now

New Webserver for Airleader Master II Controller

Airleader is a leading German manufacturer of the award winning Compressor Master Controller Professional. The demand logic and the self-learning capability are second to none. The Airleader Master Controller delivers higher energy savings as OEM offered controllers or sequencers. The universal interface makes is possible to connect to any compressor brand and model. The Airleader Web-Server comes as a part the master controller, because they believe that without a monitoring system is impossible to keep a compressed air system tuned. Integrated e-mail features are available for alert and maintenance e-mails.

The Airleader Master Controller Professional can also be used as a continuous data logger / monitoring system. Data is stored for years to come and can be downloaded for investigation (baseline) and verification (post) reports e.g. as required for custom utility incentives projects. The OPC Server is available to transfer any data point into a Third-Party monitoring system.


Central Compressor Controls

Permanent Compressed Air Monitoring

Central Compressor Controls

Optimal compressed air system performance, defined by efficiency, reliability and air quality, has now become the main goal when operating, installing, purchasing or designing compressed air products. Whether you are the air compressor manufacturer, distributor or end user – everyone in the compressed air industry needs to be aware and work towards these goals.

The December 2016 Compressed Air Best Practices article Permanent Compressed Air System Metering and Monitoring a two-stage audit is reviewed. The factory with more than 10,000 cfm was audited with a master controller for two months for the first stage which also included adding an energy-efficient dryer and VFD compressor. The two months of data automatically collected by the Airleader Master Controller revealed a massive volume of leaks. The repair of these leaks quickly became the focus of phase two.

If you missed the article, you can download it and learn how this company saw great financial benefits from the installation of permanent compressed air system metering and monitoring.

Permanent Compressed Air Monitoring Download


How to Set Up Airleader Email Alert

Learn how to set up email alerts from your Airleader Master Controller.

jan hoetzel accepts award

Airleader Wins 2016 Energy Efficiency Award Challenge

Airleader’s compressor management system was honored with the coveted Energy Efficiency Award at the 2016 Energy Award Challenge by the German American Chamber of Commerce April 8, 2016.

Airleader is in business to make your business more profitable through compressor management. Herman Miller’s Spring Lake, Michigan facility installed the Airleader Master Controller. The Master Controller helps manage the compressed air system and provides valuable data. The installation increased the efficiency and reliability of Herman Miller’s compressor system. Savings from the installation resulted in the Energy Efficiency Award for 2016 for Airleader.

“We believe that informed people make the difference. Airleader enables compressor operators to understand their system and harvest energy savings. Energy efficiency is the cheapest energy source,” ~ Jan Hoetzel, Airleader US Managing Director.

You can download the press release and read about the winning project. If you are interested in learning how you can better manage your compressed air system or if you are considering upgrading your compressors, contact us first to find out how we can improve the outcome of your project through compressor management.

“You cannot manage what you do not measure.”

Guidelines for Energy Management

The Department of Energy put together this graph of Guidelines for Energy Management. It’s an action plan that ties in perfectly with the Airleader system.

What Does a Leak Cost?

According to Compressed Air Challenge of the U.S. Department of Energy’s Office of Industrial Technologies, the total cost of 100 psig compressed air has been calculated to be between $0.18/1,000-cu-ft and $0.32/1,000-cu-ft. Fixing a single small leak in a plant quickly pays for itself. (Source: Compressed Air Challenge, www.compressedairchallenge.org)