Issue:
The thermal dissipation rating specified on the APC website is sometimes different than the value calculated using efficiency data or the UPS Efficiency Comparison Calculator.
 
Cause:
The value calculated using efficiency data or the Efficiency Comparison Calculator is based on nominal environmental conditions (25C, 230V 50Hz input), in green mode with a fully charged battery.
The values on the web are specified for less-than-nominal environmental conditions, such as maximum charging power, active AVR, high ambient temperature, etc.
 
Resolution:
Both values are correct, depending on the circumstances. Calculated values are typical for nominal conditions, and the ones specified on the website apply for worst-case scenarios.