Basic Psychrometrics: 42 Lessons for HVAC Engineers and Technicians.
Psychrometrics is often treated as a shortcut—lines on a chart, rules of thumb, or isolated calculations. In practice, this can lead to shallow understanding and costly design or operational mistakes.
At Western Allied, we believe strong HVAC systems are built on first principles, not assumptions. This is why we’re proud to share Basic Psychrometrics: 42 Lessons for HVAC Engineers and Technicians, written by former Western Allied employee and respected industry expert Mat Ansari, PE.
This book reframes psychrometrics for what it truly is: the thermodynamics of moist air—and a critical foundation for sound HVAC design and troubleshooting.
Mat Ansari, PE is a retired design-build HVAC contractor and longtime contributor to the HVAC engineering community. Over the course of his career, Mat became known for his ability to translate complex engineering concepts into clear, practical lessons for both engineers and field technicians.
Drawing from decades of real-world experience, this book reflects Mat’s belief that deep understanding—not memorization—leads to better systems, better decisions, and better outcomes.
To make the material easier to digest, the book has been divided into seven parts, each presented as its own flipbook. You can read them sequentially or jump directly to the topics most relevant to your work.