Siemens Building Technologies, Inc. has developed two CD-ROM tools to help users understand VFD technology and provide a simple method of calculating harmonic voltage and current distortion when using VFDs in building applications. The VFD "A to Z"™ CD-ROM is an educational tool that explains the company's SED2™ VFD capabilities. The SED2 Harmonee™ - Harmonics Calculator Tool program is a harmonics analysis tool that provides comparative and critically important data on the full harmonic spectrum and harmonic order values. Both CD tools are available at: www.sbt.siemens.com/HVP/Components/products/variablefrequencydrives/default.asp.