
Carrier AC’s have many styles (depending on the age) to determine the age.
Let’s look at the most common style to determine Carrier AC age.
Most Common Style – Has a Letter in the Middle

The most common way to to determine the carrier ac age is through the serial number. In the above style, the determining factor is having a letter in the middle of the serial number.
The first two digits are the week of manufacturer.
The second set of digits are the year of manufacture.
Therefore, this unit was manufactured in 2019 in week 2.
Other Styles To Determine Carrier AC or HVAC Age
Type | Identifying Feature | Year | Month |
Type 2 | Followed by 5 Numbers; primarily used in the 80’s. | First 2 Numbers | Second 2 Numbers |
Type 3 | Followed by a letter then 5 numbers; primarily used in the 80’s. | First Digit is the Year | View Letter Chart |
Type 4 | Letter followed by a number; only used in 1970’s. | First Digit is the Year in 197(x) | View 2nd Letter Chart |
Letter Chart For Type 3 ONLY
Letter | Month | Letter | Month |
M | January | T | July |
N | February | V | August |
P | March | X | September |
Q | April | X | October |
R | May | Y | November |
S | June | Z | December |
Letter Chart For Type 4 ONLY
Letter | Month | Letter | Month |
A | January | G | July |
B | February | H | August |
C | March | I | September |
D | April | J | October |
E | May | K | November |
F | June | L | December |
Concluding
If you have any other questions, be sure to comment below!
Related articles: A/C unit lifespan. What is HVAC?
Also, you can check out our blog on Goodman AC Age’s in case you need that.
I believe my unit was manufactured in 1978 I was once told. Carrier. Model 38ceo45300 serial number b880545. R-22 system. If this old can I just add r-407c to it.
Hi Wayne, you would have to check the label to see if that unit accepts r-407c.
What year would Carrier Model 40GC001100
Serial # C110591
be?
Hey Judy,
Can you email me a picture of the unit and the label? aaron@waypointinspection.com
Aaron
How Old is my Carrier AC System
Model 38DXA336713
SN#4300Y70182
Capacity:36000BTu/h
Refrigerant:R-22
Made in Korea: 38Q DAC34D20
Hi Rob, based on this serial number the unit was manufactured in the 43rd week of 2000.