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Why Choose a Multiplex Scroll Air Compressor Over a VFD Tooth or Screw Air Compressor?

Is a Variable Frequency Drive (VFD) always the most efficient?

I need a lot of air; do I need a Screw or Tooth Compressor?

What are the differences in Compressor types?

Have you asked these questions while trying to decide on the best medical air compressor technology to use for you medical facility and still don’t know the answers? Well, there is no perfect answer. There are many variables that influence the decision.

Space Constraints Redundancy Requirements Maintenance Cost
Power Usage Power Available (From Panel) Heat Generated
Piping Requirements Flowrate (Constant or Variable)  

A screw or tooth compressor can provide a lot of air, but do you need that much? You can have a VFD with it to reduce the amount of air delivered, but it can only go down so low. And you don’t want to turn a large motor ON and OFF too much as it can be damaged. So, you have a minimum run time, whether you need it to run or not and that still requires power.

The heat generated is very similar.

The scroll compressor provides much more redundancy.

Piping and Power can be split on a scroll if needed. However, Piping and Power has to be split on a Screw or Tooth.

Another option would be to install a Scroll compressor. These are small compressors (2-10HP) that can be configured in many ways. You can connect two compressors to one motor (for 15 & 20HP). You can also Multiplex them where a Control Panel monitors the air pressure and determines how many compressors to turn ON to maintain the air pressure. Since these compressors are ON/OFF, you have full output and power or no output or power. Flowrate and power usage can be compared. Below are some comparisons of different configurations of scroll compressors compared to a tooth or screw compressor.


Space is another consideration. Scroll compressors can be stacked to save space. The scroll system may actually be smaller than a comparable tooth or screw compressor package. Below is an HPX 15 or 20 (75-100 HP), which is one of Pattons Medical’s largest scroll systems (physical size).

Maintenance is completely different in these technologies and requires further review.