J & E Hall’s HallScrew Compressor with Built-in VFD and VVR

J & E Hall’s HallScrew variable frequency drive (VFD) and variable volume ratio (VVR) compressors are easy to install and maintain, are highly efficient, and are available for a wide range of applications. VVR allows the volume ratio to be adapted by moving the loading valves. By doing this, the volume ratio of the compressor is optimized for any running condition which further re-duces energy consumption.