| SUNSHINE AIR-CONDITIONING ENGINEERING LIMITED | Private company limited by shares | Live |
| New Tech Air-Conditioning Engineering Limited | Private company limited by shares | Dissolved |
| AA Air-Conditioning Trading Company Limited | Private company limited by shares | Live |
| CHUNG WAH AIR-CONDITIONING & TRADING COMPANY LIMITED | Private company limited by shares | Live |
| TAT TUNG AIR-CONDITIONING COMPANY LIMITED | Private company limited by shares | Dissolved |
| MAN TUNG AIR-CONDITIONING E & M LIMITED | Private company limited by shares | Live |
| TAI TUNG AIR-CONDITIONING & ENGINEERING COMPANY LIMITED | Private company limited by shares | Live |
| Tung Lik Air-Conditioning & Engineering Company Limited | | Live |
| UNITED AIR-CONDITIONING & ELECTRICAL ENG. LIMITED | Private company limited by shares | Live |
| VICTORY AIR-CONDITIONING & ENGINEERING LIMITED | Private company limited by shares | Dissolved |
| WANG HEI AIR-CONDITIONING ENGINEERING COMPANY LIMITED | Private company limited by shares | Live |
| Wang Tai Air-Conditioning Engineering Company Limited | Private company limited by shares | Live |
| Wang Yip Air-conditioning Engineering Co. Limited | | Live |
| ALL WELL AIR-CONDITIONING LIMITED | Private company limited by shares | Live |
| WESTCO AIRCONDITIONING LIMITED | Private company limited by shares | Live |
| WHARF AIR-CONDITIONING & ENGINEERING CO., LIMITED | Private company limited by shares | Dissolved |
| WINFUL AIR-CONDITIONING LIMITED | Private company limited by shares | Dissolved |
| WING TAI AIR-CONDITIONING LIMITED | Private company limited by shares | Dissolved |
| WING FAT AIR-CONDITIONING COMPANY LIMITED | Private company limited by shares | Dissolved |
| WING FAT AIR-CONDITIONING LIMITED | Private company limited by shares | Dissolved |
| WING MAU AIR-CONDITIONING ENGINEERING COMPANY LIMITED | Private company limited by shares | Dissolved |
| WING KEE AIR-CONDITIONING ENGINEERING LIMITED | Private company limited by shares | Dissolved |
| WING TAT AIR-CONDITIONING ENGINEERING COMPANY LIMITED | Private company limited by shares | Live |
| WING LEE AIR-CONDITIONING ENGINEERING LIMITED | Private company limited by shares | Live |
| FU WING AIR-CONDITIONING ENGINEERING COMPANY LIMITED | Private company limited by shares | Live |
| WING WO AIRCONDITIONING ENGINEERING LIMITED | | Live |
| WING FAI AIR-CONDITIONING SERVICE LIMITED | Private company limited by shares | Live |
| Wing Lee Air-conditioning Service Limited | Private company limited by shares | Live |
| WING'S AIR-CONDITIONING ENGINEERING LIMITED | Private company limited by shares | Live |
| Wing's Glory Air-Conditioning Company Limited | Private company limited by shares | Live |
| WINNER AIR-CONDITIONING ENGINEERING LIMITED | Private company limited by shares | Live |
| WINNING AIR-CONDITIONING COMPANY LIMITED | Private company limited by shares | Dissolved |
| Fai Wong Air-Conditioning Engineering Limited | Private company limited by shares | Live |
| CHIU YIP AIR-CONDITIONING WORK LIMITED | Private company limited by shares | Dissolved |
| ELECTROSTAR AIR-CONDITIONING WORKS LIMITED | Private company limited by shares | Dissolved |
| HING FAT AIR-CONDITIONING WORKS LIMITED | Private company limited by shares | Live |
| MAN TUNG AIR-CONDITIONING WORKS LIMITED | Private company limited by shares | Live |
| WORLDTECH AIR-CONDITIONING ENGINEERING LIMITED | | Live |
| WUITAI AIRCONDITIONING LIMITED | Private company limited by shares | Live |
| YING WAH AIR-CONDITIONING LIMITED | Private company limited by shares | Live |
| YAT YUET MOTOR AIR-CONDITIONING COMPANY LIMITED | Private company limited by shares | Dissolved |