Compressed air fuels many parts of many industries all over the world and is commonly known as “the fourth utility.” From the beverage servers in a restaurant or bar to the enormous rooms and extensive systems inside a manufacturing facility, air compressors play a huge role in civilization as we know it.
Pressurized air systems and the compressors that drive them hold the power to fuel business, save money and conserve energy. The more information and data you can gather about your existing or future compressed air needs, the better it can help you.
Air Compressor Basics
An air compressor converts power, most commonly from an electric motor, a diesel engine or a gasoline engine, into kinetic energy by compressing and pressurizing air that is then released in quick bursts or flows to operate equipment. Here are some common set-ups:
- A reciprocating/piston driven air compressor contains a drive shaft, cylinder valve head, connecting rod and piston that together produce pressurized air.
- A rotary driven air compressor is also called a rotary-screw compressor since the mechanical setup to produce the pressurized air is two screws rotating inside a sealed compartment.
- A vacuum-pump compressor converts energy by evacuating the air contained within a system that has a rotating shaft.
An air compressor involves two basic elements: air flow and pressure. Pressure is most commonly expressed and measured in pounds per square inch gauge (psig), and airflow is usually expressed and measured as cubic feet per minute (cfm).
Horsepower tells engine-output capacity, and while that is relevant to an air compressor’s function, volume and pressure are more important and indicative of how the machine will perform. For maximum efficiency, you want to find the compressor that uses the least horsepower to produce the most pressure.
While you seek the right combination of horsepower and cfm or psig, note the decibel-level ratings for the different air compressor models, which range from 64-130 dBA and higher. An auxiliary storage tank for the pressurized air enables you to rest the compressors more often and decrease the risk of over-taxing them.
Compare Electric to Diesel
Environment will influence your decision as to whether you’ll use an electrical air compressor or a diesel air compressor, or possibly both. Consistent outdoor work usually demands diesel, and many people who use an electric system still keep a diesel compressor around or have access to one in case of an emergency or extended power outage.
Both diesel and electric have comparable power delivery among the various models, and the number one advantage of electric air is the potential savings. A 50-hp electric compressor can cost two-to-four times less to operate and maintain than its comparable diesel counterpart, a 185 cfm with a 27-gallon fuel tank. The range is broad because the cost of a gallon of diesel fuel and a kilowatt of electricity vary from place to place.
Electric Vs. Diesel: The Cost of Operation
|Annual Op. Hours (Single Shift)||Electric Cost
While diesel compressors fit some needs, electric air compressors provide many advantages over diesel, including:
- Saving money on energy (electricity is much cheaper than diesel fuel)
- Reducing maintenance cost and frequency
- Increasing reliability & uptime – which increases productivity
- Conserving resources
- Eliminating diesel-fuel spills and leakage
- No risk of exposure to strong odor and vapors
- Producing better quality compressed air
- Emitting no carbon
- Simplifying operation
- Enhancing safety
- Involving fewer moving parts
- Achieving cooler running temperatures
- Increased peace of mind through better warranties
- Avoiding special air-circulation fixtures
- Making less noise
One case study of a big company that had an energy-efficiency audit gives a good example of how electric can save money over diesel. The business’ evaluation resulted in a $22,000 savings on its $40,000 annual expense for electricity by using a more efficient compressor and auxiliary storage.
The new system saved money and paid for itself within 27 months. It also enabled the company to use 367,000 fewer kilowatt hours per year than before the evaluation and upgrade. The analysis and result provide evidence that electric models are energy-efficient air compressors.
Another consideration for either a diesel or electric is portability. Will the compressor be stationary or will it need to move from place to place? There are air compressors, like trailer-mounted and towable types, that are made to be portable, so it just depends on what your needs and preferences may be.
Other compressors are designed to be permanent, such as on a concrete pad or in a specific room or area of the building. Wherever they’re located, they need good ventilation because part of their operation depends on drawing in air, and other operations cause heat that needs room to dissipate.
Conduct an Audit
Any expert would encourage a current owner or prospective buyer of compressors to evaluate their current system and/or needs for a system before making decisions about changes or additions. Determining your energy-efficiency quotient ends up cutting waste, which is estimated by professionals to be anywhere from 25% to 50% at more places than not. Doing an evaluation literally pays off in what you’ll save by finding out where you can eliminate waste, especially in a facility with multiple systems and different demands during shift variations.
For example, Quincy Compressor offers a service to determine the efficiency-quotient (EQ) of a compressed-air system. The process involves a representative walking through to assess the facility using an EQ worksheet, which also estimates costs and possible savings. Next, a trained energy auditor places an EQ Analyzer that records data about the compressors, pressure levels and fluctuations during typical production.
Once you have good data in hand and you know your EQ, Quincy Compressor will report findings and produce an action plan. The process includes financial projections and capital-investment scenarios plus details about how to achieve ‘best practices’ to maintain optimal system efficiency.
Good businesses and conscientious individuals want data that can help them make money and successful decisions. You might be one of the happy few whose waste percentage is at a satisfactory 15%. If not, you can likely become one after an audit of your system because sound data provides you with many benefits, including:
- Eliminating guesswork in evaluation and selection
- Saving money through improved efficiency
- Optimizing the system for longest compressor life
- Reducing down time
- Conserving energy
Many businesses and plants calculate how much compressed air they’re using and determine specifically how long a life is expected of the equipment at a certain operating capacity. Those “duty cycle” calculations can reveal much, specifically how much rest a machine needs. If a compressor has a 100% duty cycle, it can run continuously. If the duty cycle is, for example, 60-75%, the compressor would be on and actively compressing air for roughly 30 hours in a five-day week — about six hours of an eight-hour day.
Match Air Compressor Size and Type to Need
Trained air-compressor experts can help you select exactly the right product to suit your needs. The Department of Energy gives steps to get started using compressed air:
- Create a basic diagram of your current system.
- Measure your baseline and calculate energy costs.
- Work with a compressed-air expert to conceive and implement controls.
- Measure again after controls are in place.
- Check for opportunities to fix problems like improper use.
- Correct issues, then measure and calculate energy costs.
- Implement continuous quality measures.
Many factors do affect the question of, “What kind and size of air compressor or system do I need?” The answer lies in the type of work, frequency of demand, environment and to a certain extent, preferences. Most importantly, don’t go by horsepower alone. Instead look at the psig and cfm capacity to match your needs.
The audit and evaluation step will basically tell you what size of a compressor will handle the jobs you’re going to put it through. You can partly gauge need by looking at the psig requirement of the highest-demand tool in the shed. It might be a paint sprayer that needs 90 psig, hand tools that need 50 psig or items that need a much higher psig, so it’s important to get and have a compressor that is sized according to your greatest need.
Determining your cfm needs requires you to figure out how many tools you’d potentially be running at once. Then total those amounts and multiply the sum by 1.5, which accounts for bleed and inefficiencies.
Manufacturers rate an air compressor based on its horsepower and air capacity, and consumers might see various 5-hp compressors for drastically different prices and wonder: “What’s the difference?” Air capacity, motor quality, durability, components, engineering and warranty are several of the reasons seemingly similar products cost such different prices.
Reliability is the real benefit, though, considering shops can come to a stop without compressed air. It is commonly taken for granted until there is a problem and production ceases, so it’s wise to ask yourself how much you, your business or your departmental operation will depend on the compressor to do its job.
Some managers are tempted to please the budget by skimping and choosing the lowest price or going with an undersized compressor to save money. Neither of those shortcuts turn out well because any money saved on the lower price is likely to be sacrificed later in delays, replacement parts or frustration. The cheaper compressor might have an expected life of 2000 operational hours, while the costlier one could last decades.
Having the best of internal components pays off in the confidence that your compressor won’t corrode, rust, break or otherwise cause stoppage or energy leaks that lose money.
Air Compressor Care
Once you invest in a system, replacement or upgrade, you’ll want to protect and maintain it. Hot outdoor temperatures can be an enemy to electric air compressors, so good air flow and regular inspections are especially important. There are a number of preventive-maintenance steps you can take to help avoid trouble and keep your air system in top running condition:
- Do regular inspections for excessive dirt, clogged filters and leakage.
- Give the compressor ample ventilation.
- Clean coolers and external fins of the cooler.
- Check temperatures in a water-cooled system.
- Monitor drain valves in an air-cooled system.
- Watch the pressure, which will drop if it’s too hot.
- Check oil and prepare to add more in hot weather as the compressor works harder.
- Also, check the oil weekly to drain any condensate that may have formed. This is especially important for outdoor compressors in hot climates.
Quincy Compressor can help you with maintenance, service, parts, new and existing systems, green technology, air-treatment options, energy-efficient quotient (what’s your EQ?) and more. We offer everything you need to conduct research, get information, produce data specific to your business, analyze that data and develop a long-term plan that achieves maximum efficiency.
The “What” of Electric Compressors
Many different industries use compressed air to power all or part of their operations, such as:
- Oil and gas
For example, you might require a rotary air compressor if you need it to run continuously for spray-painting work. If you must power hand tools that are used intermittently during the day, a reciprocating air compressor may suffice.
Homeowners, woodworkers, contractors and mechanics might use a reciprocating air compressor. Manufacturers, small and large businesses and government would likely pick a rotary-screw air compressor.
Most people use compressed air without thinking about it as an alternative energy source that can save kilowatt hours and money. A compressor doesn’t use any power unless it’s on and running, and that’s important to consider as you evaluate energy consumption and gauge needs. If you’re inclined, you can calculate the cost of the electricity needed to power your compressor — usually in the cents-per-hour range.
The “Who” of Air Compressors
Quincy Compressor ranks as a top “who” in the air-compressor business. Our company began in 1920 with a trio of enterprising Illinois partners who found financial backing for their vacuum-pump machine, which many used for milking cows. As the demand for compressed air grew, Quincy Compressor also grew and evolved to become a leading expert of the industry and earn recognition as a solutions provider.
Our lines of compressors are engineered to master even the most challenging conditions such as mining, drilling, concrete production and shipbuilding. Along with a line of A-Z products for compressed-air systems, we offer a world of support through the best people and systems in the business. For example, you can get 24-7 help from qualified dealers and access a wealth of information in the Knowledge Center of the Quincy Compressor website, where case studies and white papers contain real-world examples.
In addition, we offer an innovative, long-term, extended warranty program, as opposed to some manufacturers that require a service contract. Quincy Compressor has 200 locations worldwide, so you can find what you need close to home. You can also get to know the compressed-air experts in your area.
Compressed air can be a huge asset since it provides a greener, cleaner and less expensive way to power business. Efficient use of the “fourth utility” definitely holds the potential to save big dollars and achieve productive results.