Ask the Expert: How do rotary and piston compressors differ in cost?

Q: How do rotary and piston compressors differ in cost?

A: Reciprocating piston compressors and rotary compressors not only differ in purchase price. They also vary in ongoing costs. Here’s what to expect:

Purchase Price: Piston compressors have a much simpler design than rotary compressors and, as a result, have a much lower purchase price. The additional components of rotary compressors, such as liquid cooling systems and air/oil separators, add a lot to the cost.

Energy Usage: One advantage of piston compressors is that they only use electricity when they’re compressing air. On the contrary, rotary compressors are designed to run continuously, even when they’re not compressing air. Granted, some rotary compressors automatically go into standby mode after idling for five or 10 minutes; nonetheless, that’s still five or 10 minutes of wasted energy, which can significantly impact the electric bill.

Maintenance: Rotary compressors generally require specialized lubricants, which, in some cases, may cost several hundred dollars for a five-gal bucket. It’s possible for a rotary compressor to rake up a $500 service bill every three to six months. In fact, total service costs can surpass the initial purchase price after only five years of use.

Overall, maintenance on a piston compressor is simpler. As long as the operator regularly changes the air filter and pump oil, the compressor is likely to provide years of trouble-free service. Furthermore, the oil for a reciprocating piston pump is much cheaper, and the quantity is less.

Information provided by: Daniel Leiss, president, Jenny Products, Inc.