The third edition of HVAC Systems — Testing, Adjusting and Balancing is now available from the Sheet Metal and Air Conditioning Contractors’ national Association (SMACNA), Chantilly, VA. The manual provides fundamentals and procedures for balancing air systems. SMACNA says The revised edition presents the basic fundamentals, methods, and procedures, including the necessary tables and charts, to adequately balance a complete HVAC system. Subjects covered include motor operation, fan curves, pump curves, and fluid flow losses in ducts, fittings, pipes and air terminals. In addition, variable frequency drives, direct digital control systems, lab hood exhaust balancing, and balancing equipment and procedures are presented. The manual is available to architects, system designers and engineers for $102; the non-member price is $147. For more information, call 703/803-2989 or visit www.smacna.org.