ANSI Z21.40.4A

ANSI Z21.40.4A is the American National Standards Institute document titled “Addenda 1 to ANSI Z21.40.4-1996/CGA 2.94-M96, Performance Testing and Rating of Gas-Fired, Air Conditioning and Heat Pump Appliances,” 1998 (ANSI Z21.40.4-1998/CGA 2.94A-M98).