| # | Organization | Country | Specialty | Web Address |
|---|
| 1 | Air Conditioning Contractors of America (ACCA) | USA | Air Conditioning & Refrigeration, Contractor | Click here. |
| 2 | Air Infiltration & Ventilation Centre (AIVC) | International | Environmental, Indoor Air Quality | Click here. |
| 3 | Air Movement & Control Association (AMCA) | International | Manufacturer | Click here. |
| 4 | Air-Conditioning & Refrigeration Institute (ARI) | USA | Manufacturer | Click here. |
| 5 | American Backflow Prevention Association | USA | Construction, Facility, Water | Click here. |
| 6 | American Boiler Manufacturer's Association (ABMA) | USA | Boiler | Click here. |
| 7 | American Council of Engineering Companies (ACEC) | USA | Professional | Click here. |
| 8 | American Gas Association (AGA) | USA | Fuel, Professional | Click here. |
| 9 | American Home Inspector Directory | USA | Construction, Consulting Engineering, Contractor, Environmental, Indoor Air Quality, Instrumentation & Control, Insulation, Residential, Water | Click here. |
| 10 | American National Standards Institute (ANSI) | USA | Standards & Codes | Click here. |
