HVAC Contracting HVAC Contracting, by Robert and William Dries. Carlsbad, Calif.: Craftsman Book Co., 1986. 251 pages $24.50 paperback. by Paul Hanke There comes a time when many people in the building trades ask themselves: "Why am I working for someone else? Should I go out on my own?" If you're in HVAC, Robert and William Dries have written a book to help you answer those questions. HVAC Contracting covers tools, installation, theory, design, and business for the budding entrepreneur. Some areas get better coverage than others, but the overview is good. After a short preface, the authors begin with an introduction to tools, equipment, and shop requirements. They assume that the reader is already familiar with the first two subjects, but they