It would be confusing and wrong. Some hvac brand also has new code for its new hvac units. For example, York hvac had two different serial numbers for 1971 through 2004 and for 2005 through the present day. You can’t use information from 2005 to decode 1980 hvac unit, it wouldn’t works. These air conditioner numbers mean a lot. Without the serial and model number, it would be hard to find a replacement part of that central ac unit (I’m not referring to small parts).