ARLINGTON, Va. - The Air Conditioning Contractors of America (ACCA) announced that it has posted on its Web site the last in a five-month series of technical reference bulletins. The new bulletin discusses duct flow.

Called "Balancing Residential Air Distribution Systems," the bulletin describes the characteristics of air and the physics of duct flow. The principles are discussed as background for 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 technical bulletin covers blowers and air-side devices, balancing instruments, and balancing procedures.

The bulletin is available for ACCA members to download at

Earlier bulletins released this year have covered such topics as carbon monoxide, duct sizing, and blower performance.

Publication date: 12/27/2004