Free Textbook on Engineering Thermodynamics | Hacker News

Hacker News discussed a free engineering thermodynamics textbook that drew praise for its clear illustrations and accessibility.

Readers asked for broader coverage of topics such as equations of state and refrigeration systems, along with related tools like CoolProp.

The author explained the self-publishing setup, including print-on-demand through Lulu and Amazon, and how sales revenue is split.

The thread highlighted both the value of a free educational resource and the tradeoffs of independent textbook publishing.