ALEXANDRIA, Va. — The American National Standards Institute (ANSI) public review period for the proposed “Addendum B” to ANSI/ACCA 3 Manual S–2023, Residential Equipment Selection, is open through Sunday, June 9.

The proposed Addendum B will supplement the ANSI/ACCA 3 Manual S–2023, and the Addendum A–2024.

The proposed Addendum B would correct definitions for “Two-Speed Heat Pump Sizing Condition” and “Variable-Capacity Equipment Sizing Condition” to be consistent with the sizing condition requirements in the standard, and therefore avoid possible confusion, a press release from ACCA said. The definitions will clarify that the parameters used for those sizing conditions are applicable to heat pumps that are used as the primary source of heat installed, as opposed to the sole source.

ACCA Manual S provides procedures for selecting and sizing residential heating, cooling, dehumidification, and humidification equipment.

A draft of the proposed Addendum B along with a comments section can be accessed by clicking on the link here.

For more information about Manual S or ACCA, contact Kate Wessels, ACCA vice president of communications, marketing, and partnerships, at or 703-824-8864.