Alexandria, VA (October 28, 2025) — The Air Conditioning Contractors of America Educational Institute (ACCA-EI) Standards Task Team (STT) announces an American National Standards Institute (ANSI) second public review for modifications to proposed “Addendum c” to ANSI/ACCA 3 Manual S® –2023, Residential Equipment Selection, as a revised industry standard.
The 30-day ANSI public review period is from October 31, 2025 to November 30, 2025. Proposed Addendum c will supplement ANSI/ACCA 3 Manual S® –2023, Addendum a – 2024, and Addendum b –2024. The modifications to the proposed Addendum c are solely based on comments received during the first public review draft on June 6, 2025.
Manual S® provides procedures for selecting and sizing residential cooling equipment, heat pumps, electric heating coils, furnaces, boilers, ancillary dehumidification equipment, humidification equipment, and direct evaporative cooling equipment. Manual S® is also a requirement specified in the International Residential Code and the Uniform Mechanical Code.
A redline review draft of the modifications is available on the ACCA website. Submit comments using the form by November 30.
Media inquiries:
Kate Wessels
VP of Communications, Marketing, and Partnerships
kate.wessels@acca.org
703-824-8864