When you consider the energy required to create each unit of compressed air, you’ll understand that compressed air is expensive, explains energy consultant, Stephen Dixon. “Your systems have to work very hard, and use a lot of energy, to get that compressed air.”
A system audit can solve performance issues and find savings along the way.
In a world where we think of air as being free, it can be hard to get your mind around that idea. Convert your compressed air use to dollars on your monthly energy bill and you’ll start to view it differently. Think of compressed air efficiency as you would energy efficiency because they’re one in the same.
A compressed air audit can get you on a path to peak efficiency.
“A compressed air audit, when done properly by people who are qualified and have reducing the consumption as their primary goal in mind, can be a very lucrative endeavour,” says Dixon.
Getting your compressed air system reviewed end-to-end to diagnose performance issues and optimize efficiency can create bonus savings. A more efficient compressed air system uses less energy which saves you money.
Direct energy savings are only one of the benefits of an efficient compressed air system. When your system is running well, you’ll enjoy lower maintenance and operating costs, increased reliability and safer operation. A system that’s working to its potential may also be able to meet your growing needs and save you investing in additional equipment. Using less energy lowers your carbon footprint and your environmental impact.
Compressed air efficiency opportunities exist throughout the system.
When you have insufficient air pressure, it’s easy to question whether your compressor has the capacity to meet your demand. According to energy auditor, Dino DeFilippis, the solution can often be found throughout the system components, including dryer, storage, piping, nozzles, and more.
“When you have a compressed air system that isn’t supplying enough pressure, digging into the issues can usually reveal significant energy savings opportunities,” DeFilippis says.
Energy saving opportunities in a compressed air audit:
Analyzing the efficiency of a system begins at the supply end in the compressor room. How can you produce compressed air more efficiently? Below is an overview of some issues and opportunities, an auditor will look for:
- Auditors will review your control strategy. A proper control strategy for a single or multiple compressor system will prevent unnecessary cycling. They will provide guidance on how savings can be found using the most efficient combination of compressors, ex. Lead/lag, VFD, fixed.
- Are your compressors sequenced to meet the load as the load is changing? “Adjust those controls to ensure the compressors are not fighting one another. Not operating in tandem, but operating in sequence, to meet the load as the load is changing,” recommends Dixon.
- Do you have a fresh air intake for the compressor room? Sufficient air intake is essential to compressor efficiency. Because cooler air is denser well-ventilated compressors will use less energy to produce the required pressure. (For example, if 32C (90o F) intake air is tempered to 21C (70o F) with cooler air from another source, the 11C (20o F) temperature drop will lower operating costs by almost 3.8%.)
- A properly sized air receiver can help you meet peak demand, control system pressure, and compressor cycling. For example, if your processes have intermittent peaks, a large receiver can reduce size of compressor needed.
- Properly sized dryers and storage also impact system efficiency.
- Air leaks in the system drive pressure loss and cost. “I have seen cases where 50% of your compressor use is for leaks alone,” explains Dixon. DeFilippis agrees, adding that “It really doesn’t matter what you generate in the compressor room. If I can’t get it to the demand side, or the end use, through the distribution, you’re simply throwing good money after bad.”
- Given that, there are tremendous opportunities to find efficiency savings in the distribution portion of your compressed air system.
- An auditor will complete a comprehensive evaluation of the distribution system. They will review your piping, looking for avoidable pressure losses and help to determine if your piping is properly sized for the system, and they’ll review your connections and fittings. Understanding where you have experienced pressure issues will also help identify energy saving opportunities in the distribution.
End-use energy saving opportunities:
- The auditor will look for additional leakage at point-of-use in your system, including issues with a cylinder, clamping device, valve, or nozzle. (An engineered air nozzles use 33% less compressed air for same blowing capacity compared to cut-off pipes.)
- And finally, an easy source of energy savings is identifying inappropriate use of compressed air. “At the end of the day, in addition to leaks, there are probably things you’re doing with compressed air that you may be able to do with other means. That may be safer and definitely less expensive than compressed air,” says Dixon.
Preventative maintenance is another efficiency tool
Up to 20% of energy savings comes from proper system maintenance. It is recommended to follow the manufacturer’s preventative maintenance schedule and recommendations. Auditors may advise you implement an in-house PM schedule on all compressors and ancillary equipment (dryers, filters, drains, etc.). As part of your own PM schedule, auditors suggest you replace components (ex. filters) based on hours of operation, rather than delta or gage indicators. A preventative maintenance program helps you avoid major issues, down time, and stress on your system.
Compressed air audits help customers realize true energy savings and avoid the capital investment of new compressors. Instead, qualified energy experts can help you implement proper preventative maintenance schedules, leak prevention programs, and best practices to reduce overall operating costs.
Helping your system work more efficiently has the added benefit of reducing maintenance costs process down time, and can help you avoid buying equipment you may not need.
A compressed air audit may be funded through your energy provider. Ask us how.