The Essential Importance of Compressed Air Efficiency

Compressed air has many uses, as it is one of the most widely used forms of energy in many industries. Approximately 70 percent of all manufacturers use compressed air systems for various tasks such as operating machine tools, handling materials, separation equipment, and spray painting. Compressed air is such a widely used resource because of its safety and convenience; however, it can also be one of the most expensive energy forms. For example, eight horsepower of electricity is needed to generate one horsepower of compressed air. In this case, it is essential to take advantage of low-cost energy conservations to save money while increasing your compressor’s efficiency.

Factors that influence pneumatic energy efficiency include type, model, size, motor power rating, system design, control mechanisms, uses, and maintenance schedule. Neglecting any of these could lead to poorly designed and maintained air compressor systems that account for $3.2 billion in wasted utility payments every year^1.

However, having an efficient air compressor doesn’t just mean saving money. Implementing energy conservations by reducing the amount of electricity needed to produce air can also help control pollution and significantly improve air quality.

When improving air compressor efficiency, it’s essential to examine the above factors mentioned and look into supply lines, air storage tanks, air dryers, receivers, and after-coolers. The proper adjustments to your system can equate to a significant amount of energy and money saved.

Below are a variety of different approaches that can improve your air compressor efficiency:

1. Install efficient equipment – Make sure to buy the correctly sized equipment to match your compressor load and select a pneumatic system that can maintain high efficiency during operation. It’s always important to get a compressed air assessment before committing to a compressor so that you can size everything correctly.
2. Purchase ample storage – Almost all air compressors can benefit from large storage receivers. A rule of thumb to follow is to install between 5 to 10 gallons per cfm rating of the largest trim compressor. It is also recommended to install secondary receivers downstream to balance pressures or high flow transient loads.
3. Keep the pressure low – Optimum systems have pressure loss of less than ten psi, meaning that anything higher than that points to pressure loss problems. Solving this complication might require oversizing, ensuring that any significant pressure loss across air dryers, filters, piping, connectors, and hoses are reduced through proper design.
4. Minimize waste – Always be sure that every piece of equipment in your compressor consumes the appropriate energy amount. Ensure there isn’t something that can be better substituted with a more conservative source. Major wasters in any system are the timer style, manual condensate drains, continuous blowing devices, and leaks.
5. Dry the air efficiently – The two most common choices for drying air are between refrigerated and desiccant drying. Desiccant drying will increase your air-drying costs by three, so only dry parts that need low dew points. When appropriate, use the refrigerated option and instead purchase more efficient cycling styles that reduce power consumption and moisture loading.
6. Monitor your system efficiency – It is vital to know the measurements of your compressor system. The recommendation is to consider installing an efficient monitoring system on your pneumatic system to ensure a reasonable power emission as well as low leak levels.

Components that improve air quality for a more efficient performance:

1. Use cool temperatures – The temperature of the intake air plays a significant role in how much energy is used to compress the air. Cold air is denser and already more compressed than hot air, meaning cold air needs less energy to be compressed.
2. Look at air composition – The air intake quality affects your system’s ability to process the air properly. Clean air ensures the system can undergo the compressor process more smoothly. Dirty air reduces efficiency and storage capacity due to contaminants that enter the system the accumulate over time.
3. Check humidity levels – Much like composition checks, the level of moisture in a pneumatic system can affect its performance level. Humid air (wet air) is harmful because the moisture can accumulate inside the system and cause rusting. Dry air is less likely to damage both your compressed air system and the tools that perform work.

Pointers to improve the air compressor system design:

1. Cool intake air – Since, as mentioned above, it is better to use cold air in your system, the recommendation is to move your compressor into a shaded outside area.
2. Straighten the path – Smooth delivery lines without bends and loops produce more pressure than a pneumatic system with narrowed lines or sharp twists. This is because that kind of design can be counterproductive for your compressor, causing increased friction and pressure drops. A system with smooth paths compared to complicated pathways can use the same energy but vary greatly in the amount of pressure these systems used to reach the point of use – all because of the line pathway.
3. Save energy when needed – A receiver tank can safeguard short-term demand changes and reduce on/off cycling. Having a tank also ensures that the system pressure won’t drop below the minimum pressure requirement. When figuring out which receiver tank to get, it should be sized depending on the compressor’s power. A 50 hp air compressor, for example, requires a 50-gallon air receiver tank.
4. Use several compressors – Oversized compressors can be inefficient because they use more energy per unit while operating with a partial load. Oversized air systems can benefit from using several small compressors, allowing portions of the primary system to be shut down just by turning off some of those small surrounding compressors.
5. Recover waste heat – Waste heat is the extracted heat energy removed before compressed air is distributed into the pipe system. The possibility of recovering this waste heat from the hot air or hot water is high, whereas 94% of the waste heat can be recovered. Waste heat can be used to boil water for space heating or heating water.
6. Locate near high-demand areas – Locating receiver tanks in the proper places can make it easier to meet demand while also reducing the compressor capacity.

Aspects to consider to fulfill your air compressors needs:

1. Minimize artificial demand – Artificial demand is the extra pressurized air in the system that is not being used. This means that the pneumatic system is always running as though it needs to provide pressurized air, even if the actual demand isn’t there. Utilizing pressure regulators at the end can help minimize this problem.
2. Find the correct pressure needed – Pressure requirement is different depending on the process operation and application, so it’s important to know the air requirements. Required pressure levels must consider system losses from dryers, separators, filters, and piping. Raising the compressor discharge pressure increases the demand for unregulated usage, which average as high as 30-50% of overall air demand. It is recommended to establish the target pressure and flow to save on energy costs. (take from CDA + Current Pressure Requirements)
3. Examine proper supply and demand – Having a general assessment of an entire compressed air system should provide an insight into the distribution system. Doing this can display the problems and minimize the potential for inappropriate air usage.
4. Use block diagrams and pressure profiles – A block diagram is a schematic form to help identify all air compressor system components. A pressure profile reveals pressure drops in the system, which provides feedback that allows adjusting controls. Utilizing these tools can help determine system disruptions, intermittent loads, system changes, and general conditions. Having this information provides for oversight that can minimize the impact on production.

Finally, tips maintain the quality of your compressor:

1. Change filters – Filters ensure that clean air reaches the user. Dust, dirt, and grease can clog filters, which cause a drop in the system air pressure. If these filters aren’t cleaned, the drop-in system air pressures force the system to generate more energy to maintain the same pressure. Be sure to use low-pressure drops and long-life filters to save energy. Filters should be sized based on their maximum rate of flow.
2. Maintenance – It’s important to know the steps to care for your specific compressed air system and train employees on these procedures. Just checking in on your system can keep it running efficiently for many years.
3. Fix leaks – Leaks waste energy and can cause drops in system pressures that can decrease a system’s efficiency. Even small leaks can be very costly, so detecting and fixing leaks can reduce energy loss to less than 10 percent. Leaks can occur anywhere in the system, but most occur in pressure regulators, open condensate traps, shut-off valves, disconnects, pipe joints, thread sealants, couplings, hoses, tubes, and fittings. An ultrasonic acoustic detector offers the best chance of locating leaks by recognizing the hissing sounds to detect the leakage. If you don’t have an ultrasonic acoustic sensor, you can apply soapy water to a paintbrush and apply it to suspected areas, where soap bubbles will form in places where a leak is. Once the leak is located, repairs can be as simple as tightening components or require replacing couplings, pipe sections, hoses, joints, traps, fittings, or drains. Having a proper leak prevention program is suitable for identifying and addressing future leaks, which should include some of the following: determine the cost of air leaks, identify leaks, document the leaks, document the repairs, and have periodic reviews.

FS-Curtis offers high-quality and high-efficiency compressors that can help save money and energy for your business. To learn more, visit www.fscurtis.com.

Source: https://www.cagi.org/working-with-compressed-air/benefits/cost.aspx#!prettyPhoto).