ACCA (Air Conditioning Contractors of America) is the primary US trade association representing HVAC contractors, with over 60,000 member businesses. ACCA develops technical standards, provides training and certification, and advocates for the HVAC industry at the federal and state level.
ACCA is best known for developing the Manual series of HVAC design standards: Manual J (load calculation), Manual S (equipment selection), Manual D (duct design), and Manual T (air distribution). These manuals are referenced in most US building codes.
ACCA also offers the ACCA Quality Assured (QA) program, which recognizes contractors committed to technical excellence, and provides government relations support on issues including refrigerant regulations, energy efficiency standards, and workforce development.