This useful book about hot water heating is written in a question and answer format. Some of the systems covered in this book are: gravity systems, indirect radiation, diverter tee systems, loop systems, and radiant heating. One hundred years worth of hydronic heating questions (over 600 in all!) are covered, and answered in plain English. There are also easy-to-follow illustrations. This is a terrific reference book and one you'll be glad that you added to your library.