Research has shown that handy, pocket-sized reference guides with a plastic comb binding are what the worker at the job site uses most often. This one, a companion to the three-volume Audel HVAC Library, covers essential information for the HVAC technician who deals with both residential and commercial heating, air conditioning, and refrigeration systems. For easy look-ups on the job, it’s clearly organized for quick reference and features must-have tables, charts, metric conversions, drawings, measurements, materials lists, and much more.