Air compressors are among the most widely used equipment in the industry. They find utility in electronic, automotive, construction and manufacturing industries among others. However, the wide range of available compressor types and prices make their purchase an extremely difficult decision. To avoid wasting your time and money on the wrong air compressor and save yourself of future compressor troubles, consider the following before buying your air compressor.

Three main types of air compressors are commonly used in industries.

Rotary Screw Air Compressors: They use twin screws to compress air and store it in high-pressure tanks. Rotary compressors cost more than reciprocating compressors. They can run full-time, have a duty cycle of 100 percent and are most-suited to applications requiring continuous use. Rotary compressors can provide 1500 CFM of air flow in a single stage and over 2500 CFM in two or more stages.

Reciprocating or Piston-driven Air Compressors: They use pistons to compress air and store it in high pressure tanks. Reciprocating compressors are the most economical. They are designed for part time use and highly suitable for intermittent applications including portable applications and home workshops. Small air compressors produce 5 HP or less while larger compressors reach thousands of HP. Reciprocating compressors reach up to 50 CFM with a single stage and up to 100 CFM with two or more stages. One HP commonly produces 4-5 CFM of air flow.

Centrifugal Air Compressors: They are turbine engines, used in power plants and high-end industrial applications, and compress air through rotating blades. They are the costliest of all air compressor types. Centrifugal compressors operate at 400-8000 HP and produce airflows higher than 1000 CFM.

Add-On Utilities and Oil-Free Compressors:

Dry, cool and clean air allows you to improve the longevity of your manufacturing equipment.

Driers: They remove moisture from compressed air for water-sensitive equipment.

Coolers: They lower compressed air temperature.

Filters: They remove impurities such as oil and dust from compressed air.

Oil-free compressors: They provide oil-free or oil-less air for oil sensitive equipment such as food applications and semiconductors and use compression chambers sealed off from the oil-lubricated machine parts. They are much more expensive than regular rotary and reciprocating compressors.

Compressor Space: Air compressors generate a lot of heat and noise. If possible, allocate a separate compressor room to contain the noise and vent the heat. Alternatively, if you do not have enough space, an enclosure can be used to reduce heat and noise from the compressor. Reciprocating compressors are louder than rotary compressors.

Power Requirements: Compressors can be powered by electricity or with a gasoline or diesel engine. Energy requirements vary from 100V to 500V and above, depending on compressor size.

Mobility: Pay careful attention to handles, wheels and compressor weight when looking for a mobile compressor. Engine-driven compressors usually come with their own mobile trailers. When short on floor space, opt for vertically oriented compressors to save space.

Pressure and air flow: Carefully determine the air pressure and air flow requirements for every piece of your equipment and find a compressor that can run all your equipment. Air pressure and flow information is usually available within equipment documentation. If you can’t find this information in the documentation, contact the manufacturer for an educated guess. Add up the airflow values and multiply the sum by 1.5. Select the highest air pressure and increase it slightly. Make sure your chosen compressor’s air flow and pressure ratings match these values.

Consider Future Expansion: Reciprocating air compressors have an average life of 10-15 years while rotary compressors have a lifespan of 20-30 years. Consider the air flow and pressure needs of equipment you wish to buy in the near future before selecting the air compressor type and size. Make sure your selected air compressor can meet both your present and future needs for maximum benefit.

Air Compressor Pricing: Air compressors are available in a wide range of prices from $500 for a less than 1 HP power compressor to over $50000 for 200HP or more compressors. 5 HP reciprocating compressors cost $1500-2000 and 5 HP rotary compressors cost $2500-4000. At 10-25 HP, compressor prices range from $4000-$10000 or more. 50 HP compressors cost between $12,000 and $15,000 and 100 HP compressor prices range from $20,000-$30,000. Oil-free compressors costs are almost triple the price of regular air compressors. Individual compressor parts and repair services are also available. If upfront payment is a problem, you can ask your dealer for financing, leases or monthly rentals. New compressors come with at least a 1-2 year warranty and service contract. Used compressors are also available in the market. Two-stage models, that recompress compressed air for higher compression, are available in both rotary and reciprocating compressors and are costlier than one-stage air compressors.

Energy costs: These costs make up over 70-90 percent of the total ownership costs of an air compressor, over a 5-10 year period. So make sure you select efficient air compressors over inefficient low cost ones for long run financial benefits. Before purchasing an air compressor, ask your dealer for its Compressed Air and Gas Institute (CAGI) data sheet to evaluate its energy efficiency readings.

Manufacturer and Dealer Considerations: Select a manufacturer committed to producing air compressors as mainstream equipment. Talk to several air compressor dealers and get information on multiple brands, before selecting a dealer. Enquire about dealer reputation and longevity in the business, number of staff members available for compressor service and service rates. Get references from dealers and ask them about dealer performance. You can also ask your industry contacts about their air or gas compressor dealers to assist you in dealer selection. Dealers with favorable market reputations and 15-20 year experience are well versed with compressor problems, and can offer better and faster support and service.

Make sure you pick an efficient air compressor with sufficient air flow and air pressure from a reputed and experienced dealer to get maximum benefits from your air compressor. Air and gas compressors are your long-term friends, so take your time and avoid any haste in making your purchase decision.