There are a lot of HVAC books you could read, but they are not the books I'd recommend. Most of HVAC is truly a hands-on learning process, either in class or in the field. Very few people can pull technical information out of a book and successfully digest it into their memory and decision making processes. You need to be able to apply the information, or it is almost useless to you.
For example, when I taught my college class in Instrument Flying, I could explain the effects of a turn on a magnetic compass, but almost no one would get that mental "light to go on" until they saw what happens in the actual aircraft. Sure, you can study the fundamentals until they are second nature, but that "eureka!" moment happens when you are in front of a unit that is misbehaving.
Instead of limiting yourself to HVAC books, you can entertain yourself and grow mentally at the same time by reading some classic literature.
As recently as the early 50's, most educated people had read the Bible, at least once. Most had read some Shakespeare, if nothing else, a scene from
Hamlet or
Macbeth. A good course in high school would have taught both of them. And, of course,
Romeo and Juliet.
Here are some of the classics I read from 7th to 9th grade.
http://classiclit.about.com/library/...l-9th-read.htm
I'd also throw in some John Steinbeck, such as Travels With Charlie, and for creepiness, Edgar Allen Poe's
The Cask of Amontillado or
The Telltale Heart.
If you want to go deeper, try Homer's
Odyssey or
The Iliad. Both are excellent.
Dickens, Austen, Bronte...there is so much more.
Now, a lot of people will tell you that none of this is necessary. Carefully regard who it is that tells you that, and decide if you want to be that person, or someone with a little more going on "up there."
