ARLINGTON, Va. - The last in a four-part series of technical bulletins on balancing residential air distribution systems is now available at the Air Conditioning Contractors of America (ACCA) Web site.

This edition of the series discusses return- and supply-side balancing procedures, airflow measurements, seasonal balancing, and the final report.

The series is based on the concept that the air side of residential comfort systems must be tested, adjusted, and balanced in order to avoid equipment failure and ensure that the system delivers a full measure of comfort to homeowners, says ACCA.

The bulletin is available for ACCA members only, and can be downloaded at

The first, second, and third parts of the series are still available online. Part 1 covers the characteristics of air and the physics of duct flow. Part 2 discusses blower performance and the interaction between blower and air distribution system. Part 3 introduces the instruments and techniques used to measure flow and pressure.

Publication date: 05/23/2005