This revision of ASHRAE¿S Fundamentals of Psychrometrics self-directed learning course book addresses the use of psychrometrics and the psychrometric chart for typical applications and systems. It is intended for HVAC designers of various backgrounds and to be an introduction for those new to psychrometrics. This second edition of the course was rewritten in an attempt to teach the fundamentals of psychrometrics in about half the time as the previous version. The author has used his 41 years of experience in the HVAC industry as the expertise for the format and content. Skill Development Exercises at the end of each chapter help readers assess their understanding of the material and apply what they learn to real-world situations. Answers to these exercises can be submitted online to earn PDH, CEU, or LU credits.