Adults have been printing textbooks Anna technical trades for 150 years almost they are the main leader on ease of use and understanding in this book on refrigeration home and commercial includes air conditioning your home refrigerator for your storage facility it will go into every aspect of refrigeration it is a look you not only would want in your shelf in the office but on the truck for reference this thing is awesome and it doesn't get any better than this for the trade please take a look at the pictures and ask any questions you might have thank you for looking