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.
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 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.
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.
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.
“YOU CANNOT MANAGE WHAT YOU DO NOT MEASURE”
ComEd Chicago Heights Steel Case Study