How to find furnace, condenser, heat pump, and air handler manufacture date.
Most HVAC systems encode the manufacture date in the serial number on the unit nameplate.
To find HVAC age, locate the equipment nameplate and read the serial number. Many manufacturers encode the manufacture year, and often the month or week, directly in that number. The exact rule depends on the brand.
Using the model number. HVAC model numbers describe tonnage or configuration, not usually the manufacture date.
Reading the wrong piece of equipment. Condenser, furnace, evaporator coil, and air handler may all have different ages.
Assuming the installation date equals manufacture date. Equipment can sit in inventory before installation.
Use the dedicated decoder pages for Carrier, Goodman, Rheem, and Trane. Those pages explain each brand's serial format in more detail.
If you have the serial number, go straight to the serial number decoder. If you only know the brand family, start from the HVAC decoder page and open the matching brand.