Age of Carrier A/H

[mflanzbaum]

Does anyone know the age of this heat pump air handler?
Carrier Model 40A0036-300BB S/N PLA12057. House was biult in 1982.
Thanks for any help.

[grusk]

From what I have in my notes, 12th week of 2005.

Carrier, Bryant, Payne, Day & Night: Recently (last 20 years or so) the first four
numbers in the serial number represent the week and year. Previously, it was a series of letters and single digits as explained below.
Through 1969, the first digit of the serial number indicates the year of manufacture.
Example: 3xxxxxx = 1963, 4xxxxxx = 1964, etc.
1970 and later, a letter followed by a number indicates the month and year of
manufacture. Example: A1 = January 1971, B1 = February 1971, C4 = March 1974 etc.
A = Jan
B = Feb
C = Mar
D = Apr
E = May
F = Jun
G = Jul
H = Aug
J = Sep
K = Oct
L = Nov
M = Dec