ARLINGTON, Va. - The Air Conditioning Contractors of America (ACCA) has posted on its Web site the first in its 2005 series of technical reference bulletins.

"Balancing Residential Air Distribution Systems (Part II)" is the second of a multi-part series devoted to the subject of balancing the air-side of residential comfort systems. This edition discusses blower performance and the interaction between the blower and the air distribution system.

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, says ACCA.

The bulletin is available for ACCA members to download at The first part of the series, which describes the characteristics of air and the physics of duct flow, also remains available online.

Publication date: 02/28/2005