We often receive calls from customers asking for a quote on a “new, efficient” rotary screw compressor. It is true that many advances have been made in recent years (particularly in the control systems), however rotary screw compressors have been around for decades. It is also true they can be very efficient but only when sized correctly and in the right application. So what do we need to know to make an informed decision? For most applications over 30 horsepower you will probably use a rotary screw compressor. Under 30hp there is a wide variety of both piston and rotary screw compressors manufactured by DV Systems to choose from. The main point is rotary screw compressors can run at a very high duty cycle (actually a 100% duty cycle). In other words a rotary screw compressor can sit running and producing air 24 hours/day, 7 days per week. Try that with a piston compressor – depending on the quality it may not last a day. Applications that have a fairly constant consumption of air are ideal candidates for rotary screw compressors. An example would be automated machinery on a production line. Another consideration is sound level. Most enclosed rotary screw compressors are far quieter than reciprocating compressors. At first glance maintenance appears to cost more on a rotary screw compressor but if it is sized correctly over the lifetime the cost per cubic feet of air produced should be less on a rotary screw compressor. The best application for piston compressors are in instances where the air consumption is very intermittent. Examples would be smaller car repair shops, machine shops and anywhere manual tools are used. Call us at Centrair Air Systems and we would be happy to help you in the selection process.