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

This edition of the series introduces the instruments and tools used to balance air distribution systems. Included are devices that measure velocity, pressure, and airflow. The discussion includes relative costs and ease of use of various instruments.

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 the homeowners.

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

The first and second parts of the series are still available online. The first covers the characteristics of air and the physics of duct flow, while the second discusses blower performance and the interaction between blower and air distribution system. The fourth and final bulletin in this series will be released next month.

Publication date: 04/11/2005