This is a great book. I would have to agree that it goes into great depth in somethings and not so much in others. As far as HVAC goes, this book is very good at explaining the details of every system. I am not interested in refrigeration as much but if that is what you are looking for, there is really good detail about that as well. My only complaint is I wish they would make it in PDF form. Being almost 1300 pages and a hard back book makes this thing a GIANT so I don't really get to take this to work with me to study over it. I would recommend this book for anyone that is looking to self teach or needs it for a class.