أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
There are lot of ways to learn now a days too many websites are providing lot of information
We can inquire and read about items in this following sites:
https://en.wikipedia.org/wiki/HVAC
https://www.youtube.com/watch?v=uqcyenwQo
http://electrical-engineering-portal.com/download-center/books-and-guides/hvac-guides
