The Air Conditioning Contractors of America (ACCA) has announced its intention to update ANSI/ACCA 3 Manual S - Residential Equipment Selection.

The ACCA board has approved this critical update to investigate expanded tolerances for cold climate heat pumps, solidify guidance for dehumidifier sizing, and clarify requirements for code compliance.

ACCA will form a working group of industry leaders to update Manual S. ACCA is aware that today’s housing stock is constructed to be more energy-efficient and requires less heating and cooling. Therefore, ACCA will consider this, along with the improved heating capacity of multi-stage and variable speed heat pumps, which may allow them to provide heat for an entire dwelling. Updates to Manual S will guide contractors to select the right equipment based on expanded performance data rather than marketing claims.

ACCA will also examine current dehumidification guidelines. The standard currently bases its sizing tolerance on a 55 percent indoor Relative Humidity (RH) indoor entering air condition. Guidance for 50 percent RH indoor air condition will be considered.

“ACCA’s updated equipment selection standards will provide improved guidance, which will reduce errors in oversizing equipment,” says Matt Akins, ACCA manager of education. “This will ensure HVAC equipment meets the needs of today’s home, and the expectations of our members’ customers.”

ACCA maintains accreditation as an American National Standards Institute (ANSI) Standards Development Organization (SDO). This continued accreditation as an SDO allows ACCA to create nationally recognized standards that strengthen the HVACR profession, and provide references for other SDOs, model code developers, related trade organizations, and Authorities Having Jurisdiction. ACCA’s industry-developed consensus standards uphold the requirements to design, install, and maintain HVACR systems correctly and in a professional manner.

For more information about updates to ANSI/ACCA 3 Manual S - Residential Equipment Selection, contact Wes Davis, director of technical services at wes.davis@acca.org or 703-824-8847.