Rotary Screw Air Compressor Horsepower
When you’re shopping for air compressors, you’ll typically find that they’re rated by horsepower: You’ll see the horsepower rating prominently featured in the product name and description, such as the “Quincy 7.5 hp rotary screw air compressor,” the “Quincy 30 hp air compressor” or the “Quincy 60 hp air compressor.”
One of the most important decisions you’ll have to make when choosing a rotary screw compressor is the amount of horsepower you need the compressor to provide. Horsepower is essentially a measurement of the amount of mechanical energy the compressor uses to complete the compression function.
Air compressor horsepower is further defined in terms of peak horsepower (also known as brake horsepower) and running or rated horsepower. Peak horsepower is the maximum hp output the motor is capable of producing while the start windings are engaged, and can be as much as seven times the rated horsepower.
However, using peak hp to evaluate a compressor’s power capacity can be misleading, as the motor only reaches its peak hp level when the compressor is starting up. Rated horsepower can provide a more realistic measurement of the compressor’s true capacity, as it provides the hp level after the running motor has reached its designated RPM and the start windings are no longer engaged.
Other Horsepower Factors to Consider
When evaluating rotary screw compressors, you should also consider its duty cycle. This indicates whether the compressor can run at full load horsepower on a continuous or only an intermittent basis. Additionally, you should determine the compressor’s service factor, which is the percentage of rated horsepower at which the compressor motor can be operated safely. Generally, the higher the service factor, the greater the motor’s capacity to handle higher temperatures or other demanding operating conditions without overheating or failing.
Is Horsepower Really That Important?
Many people buy compressors using the horsepower rating as a primary factor. However, it’s important to know that horsepower only refers to the motor’s ability to power the compressor pump. The higher the horsepower rating, the more efficiently the pump can fill the air tank and the lower the compressor’s recovery time.
Horsepower has no impact on the airflow from the tank to the tool or equipment you’re using: A higher horsepower doesn’t enable your tool to work faster.
While you certainly need enough horsepower for your compressed air applications, you also need to consider cubic feet per minute (cfm), which provides a true indication of how much air the compressor can actually deliver. The larger the pneumatic tool, the higher the cfm generally required to operate it. To determine the appropriate compressor cfm, add up the total cfm requirements for all the tools you operate simultaneously and then choose a compressor with a cfm that exceeds this amount by 20-25 percent.
Contact Us for More Information About Rotary Screw Compressor Horsepower
Quincy Compressor offers a wide range of rotary screw air compressors with various horsepower ratings. We manufacture high quality 7.5 hp rotary screw air compressors, 25 hp rotary screw air compressors, 50 hp rotary screw air compressors, as well as both smaller and larger hp capacities. Contact your local authorized distributor to learn more about choosing the right hp for your compressed air requirements.