I'm a mechanical engineer & used a refrigeration data book for solving the vapour compression system problems...

But now, I got another book where all the values of hf & hg were different. I think the values of hfg are similar in these 2 books. In the second book, it's given that the datum taken is -40 degree celsius. So, will there be any trouble when I slove problems using this book?

If anybody wants, I can quote some values of any refrigerant at a particular temperature from these 2 books....

Please help...

Regards,
Bimal :-)