There are many items to consider when you are buying a new air compressor. When you are trying to decide whether to go with a rotary screw or reciprocating compressor an understanding of what and how you are using the air is critical to making the best decision for you. Listed below are five reasons not to buy a rotary screw compressor.
Duty cycle. Your application only requires intermittent use. Although a rotary screw compressor is designed to handle continuous duty applications where air delivery needs to be consistent, it is also more than capable of running in an environment where air use is inconsistent. If your application only requires intermittent use, a light duty reciprocating/piston compressors might be a better option.
Cost. Budgets are a concern in every major purchase decision. Generally rotary screw compressors cost more than reciprocating compressors. The initial cost may be saved over the lifetime of the compressor but if you are not factoring in lifetime costs then the initial outlay may be too much. If cost is a major factor in the decision process, then a rotary screw compressor is likely not right for you. The good news is rotary screw compressors are becoming less expensive as they gain greater acceptance in the market.
Air flow. Low air requirements are suitably handled by smaller compressors. Rotary screw compressors start to out-perform reciprocating compressors above the 30-40 CFM range. For air requirements less than that, a reciprocating compressor may be your better option.
Maintenance. The most common rotary screw compressors require oil for compressing the air, cooling and lubrication. That oil requires regular maintenance. An oil filter and coalescing filter are also unique to a rotary screw compared to a reciprocating compressor. Many screw compressors require specific synthetic oils that can be expensive. Reciprocating compressors also require oil changes but don’t usually have more expensive synthetic oil requirements.
Life expectancy. Rotary screw compressor can last thousands of hours with the correct maintenance. Low-cost reciprocating compressors usually don’t last nearly that long without being rebuilt multiple times. If your application calls for a compressor that doesn’t need to last for thousands or tens of thousands of hours, then a piston compressor could be a better choice.
When making your buying decision for a new mobile air compressor system, there are many more factors that need to be considered. This list highlights some of the major differences between rotary screw and piston/reciprocating compressors.
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