Introduction:

Compressed air systems are widely used in industries and are a major source of energy consumption. In most cases, the energy consumption costs of a compressor during its lifecycle outweigh its capital and maintenance costs. However, despite this, many industries focus mainly on capital costs during new system purchases. This mismanagement can result in a 30% increase in specific energy consumption of a compressor. This case study clearly demonstrates how a smart monitoring system for compressed air systems can help businesses save significant costs on energy, maintenance, and repair expenses. The case study also shows how the initial investment in a monitoring system pays off in just under six months, making it a worthwhile investment for businesses looking to optimize their compressed air systems.

Why Measure Your Compressed Air System?

The key performance indicators like flow, power, pressure, dew point, etc., should be measured at the right locations to understand the overall system dynamics. The improper alignment of the supply and demand side of the system results in overcompensation of system pressures and increases artificial demand and related problems like higher energy bills, higher repair intervals and costs, higher air demand, and less profit. Therefore, a well-designed system should define these KPIs to maintain the supply side efficiency.

Case Study:

An automotive component manufacturing plant in the capital city of Tamil Nadu was consuming close to 1300 CFM from 2 of their Rotary Screw Compressors of capacity 850 CFM and 450 CFM, respectively. The compressors came with an installed motor capacity of 132 kW and 75 kW, respectively. On papers, these compressors were showcasing a specific energy consumption of 0.16 kW/CFM, which appears acceptable. The factory had set itself an ambitious target of reducing their consumption to 600 CFM but was clueless about where to start.

With consultations from WiseAir Technologies, Coimbatore, the factory installed a smart monitoring system to measure the total volume of compressed air generated and consumed at different production departments. The WiseAir Monitoring System, when installed, revealed that both the compressors put together were generating only 1120 CFM as against their rated capacity of 1300 CFM but were consuming close to 220 kW put together. Hence the real specific energy consumption of these compressors was at 0.196 kW/CFM, an increase of over 18% from the manufacturer’s claims.

Extensive service and maintenance were carried out on these compressors, and the result was a reduction in specific energy consumption to 0.17 kW/CFM. The factory was able to realize a power savings of over 537 kWh per day or Rs 12.56 Lakhs per annum.   

On the Demand Side:

The measurements also revealed that the assembly and curing departments were consuming close to 800 CFM as against their actual demand of nearly 300 CFM. The painting booth was also consuming close to 320 CFM as against the actual demand of only 50 CFM. With this data in hand, the factory optimized the operating pressures of the machines, thereby eliminating artificial demand and saved close to 150 CFM and further reduced a volume of 350 CFM by repairing leakages. The project resulted in savings of up to 500 CFM, and at a power cost of Rs 6.5 / kWh, the realised annual savings were Rs 47.73 Lakhs.

Consistency of Savings:

The factory has carried out periodical leak surveys in the past with both internal maintenance teams and external agencies. While there has been a reduction post the leak repair projects in the past, there has been no consistency in the savings as new leaks do occur soon, and it turns out to be a tedious effort to locate and fix them. However, with the present WiseAir Monitoring System, the consumption of each department is monitored on a daily basis, and any rise in consumption is immediately addressed. This has resulted in reduced and easy maintenance. The WiseAir Monitoring System was installed at this factory in 2020 and even after 2 years the factory Continues to maintain the savings achieved and even has lowered their consumption to 560 CFM as against the Post Project Consumption of 620 CFM. The factory also Saved Close to 60 % in their  Spares Costs Since it avoided the purchase of huge spares which are usually listed out by external leak survey agencies during their surveys.

Return on Investments :

The Return on Investments for this Project including WiseAir Monitoring System and the Spares that were utilised was just under 6 Months.

Conclusion:

The case study highlights the importance of measuring and monitoring a compressed air system to achieve significant cost savings. In this case, the automotive component manufacturing plant was able to reduce their compressed air consumption from 1300 CFM to 560 CFM and save up to 30% in their compressed air costs.

The installation of the WiseAir monitoring system helped the plant identify the inefficiencies in their system, such as the overcompensation of system pressures and the artificial demand caused by incorrect operating pressures in the machines. The monitoring system also helped the plant to address the rise in consumptions immediately, resulting in reduced and easy maintenance.

The case study shows that investing in a smart monitoring system and consistently monitoring the compressed air system can result in significant cost savings, reducing energy bills, repair intervals and costs, and increasing profits. The return on investment for this project was just under 6 months, making it a highly profitable investment for the plant.

Overall, this case study emphasizes the importance of measuring and monitoring compressed air systems to achieve maximum efficiency and cost savings. By doing so, businesses can significantly reduce their energy bills, lower their cost per product produced, increase their profits, and achieve a quick return on investment.