Show HN: Free textbook on engineering thermodynamics

Love the price transparency, the obvious followup question is where the other ~85% of the pie goes when I buy a ~50€ paper book, if the author only earns a little under 15%?

I imagine printing will be about 2 to 5€, if it's not ultra cheap print on demand refuse. Is the rest all for publishers and Amazon dot com?

Re: Show HN: Free textbook on engineering thermodynamics

#6

Post by rationalist » Sun, Apr 26, 2026, 5:35 PM UTC

RITESH1985 wrote: post #3

[flagged]

I suggest clicking on the link and easily discover for yourself.

Re: Show HN: Free textbook on engineering thermodynamics

#7

Post by ninalanyon » Sun, Apr 26, 2026, 5:38 PM UTC

RITESH1985 wrote: post #3

[flagged]

A scan of contents list suggests that it is mostly about heat engines. No mention of chemistry. Chemical reactions are mentioned in passing in the text but with no detail. Also no obvious signs of much interest in conduction, convection, or radiation.

So it's fairly narrow focus, but that is not necessarily a bad thing.

Re: Show HN: Free textbook on engineering thermodynamics

#8

Post by 2DcAf » Sun, Apr 26, 2026, 5:38 PM UTC

tux3 wrote: post #5

Love the price transparency, the obvious followup question is where the other ~85% of the pie goes when I buy a ~50€ paper book, if the author only earns a little under 15%? I imagine printing will be about 2 to 5€, if it's not ultra cheap print on demand refuse. Is the rest all for publishers and Amazon dot com?

Amazon takes the lion’s share, and then the rest of the pie looks very different depending on which route you go. Big publishers print in batches and have very low print/distribution costs. I ended up on the other end of the spectrum, self-publishing with Lulu (print-on-demand, so much higher costs). I wrote an article in French on exploring the economics of textbooks, from the open-source point of view, a few years back: https://framablog.org/2022/01/20/mais-ou-sont-les-livres-uni...

Re: Show HN: Free textbook on engineering thermodynamics

#9

Post by 2DcAf » Sun, Apr 26, 2026, 5:41 PM UTC

quibono wrote: post #4

Nice, I’ll definitely check this out. You might want to look at optimising the PDF, it’s sitting at 40MB right now.

Thanks! I think most of the weight comes from the PNG diagrams, but I don’t actually know: I’ll put it on my to-do list to investigate, maybe there are some easy wins here.

Re: Show HN: Free textbook on engineering thermodynamics

#10

Post by 2DcAf » Sun, Apr 26, 2026, 5:43 PM UTC

ninalanyon wrote: post #7

RITESH1985 wrote: post #3

[flagged]

A scan of contents list suggests that it is mostly about heat engines. No mention of chemistry. Chemical reactions are mentioned in passing in the text but with no detail. Also no obvious signs of much interest in conduction, convection, or radiation. So it's fairly narrow focus, but that is not necessarily a bad thing.

Indeed! Truth be told, I think the book really is missing a chapter on refrigeration systems. I had to call it done at some point for my own sanity. Maybe someone will jump in and add one someday!