R-12
I don't have much time around chillers myself, and would like to know more. I cleaned one while in the Navy (condenser water side, what we called "water lancing" to push out all the barnacles, etc.) and I've studied about them in books, perhaps the best I've read on them is in this book:
Available at bookstores or Amazon.com. I learned about such terms as "approach", basic sequence of operation (similar to some of the "light off" procedures we did in my ship's engine room), COP, etc. I think this book covers the subject much better than the much exalted "Modern Refrigeration and Air Conditioning Book". I'll go on to say this book is written better than "Modern", and I thought for years "Modern" was the bee's knees.
Psychrometrics: the very foundation of HVAC. A comfort troubleshooter's best friend.