Your air conditioner’s model and serial numbers can tell us a lot more than you might think.
Depending on the manufacturer, we may be able to determine your system’s age, size, equipment type, and other useful information just from the numbers on the equipment label.
Don’t feel like decoding it yourself?
Ask Klein.
Enter the brand, model number, and serial number exactly as they appear on the label, and we’ll see what your A/C is hiding.
Not sure where to find them? Look for the equipment data plate or sticker on your outdoor unit or air handler.
Manufacturers have used different numbering systems over the years, so some older or unusual equipment may require a little more digging.
Goodman, Amana, and many Daikin unitary systems use model and serial numbers that can tell us the equipment’s manufacture date and nominal size.
On many modern Goodman and Amana systems, the serial number begins with a four-digit date code.
First 2 digits = Year
Next 2 digits = Month
For example:
2505123456
25 = 2025
05 = May
This unit was manufactured in May 2025.
Another example:
1808123456 = August 2018
Older equipment and some Daikin product lines may use different serial-number formats.
Many Goodman, Amana, and Daikin unitary model numbers contain a three-digit capacity code:
018 = 18,000 BTU = 1.5 tons
024 = 24,000 BTU = 2 tons
030 = 30,000 BTU = 2.5 tons
036 = 36,000 BTU = 3 tons
042 = 42,000 BTU = 3.5 tons
048 = 48,000 BTU = 4 tons
060 = 60,000 BTU = 5 tons
For example:
GSXN403610
The 036 indicates approximately 36,000 BTU, making this a 3-ton unit.
The letters and numbers before and after the capacity code can identify things like the equipment type, product family, generation, and efficiency class.
However, the exact efficiency of a complete HVAC system can’t always be determined from the outdoor model number alone. The final SEER or SEER2 rating can depend on the specific indoor and outdoor equipment combination.
Give Ask Klein the brand, model number, and serial number exactly as they appear on the equipment label.
We’ll do the decoding for you.
These brands are part of International Comfort Products (ICP) and commonly use the same model and serial number systems. The numbers can help determine the equipment’s manufacture date and nominal size.
On many ICP systems, the serial number begins with a letter followed by a series of numbers.
A common format looks like:
A231512345
In this format:
First letter = Manufacturing plant
Next 2 digits = Year
Next 2 digits = Week of the year
For example:
A231512345
23 = 2023
15 = 15th week
This unit was manufactured during the 15th week of 2023, or approximately April 2023.
Another example:
L192412345
19 = 2019
24 = 24th week
This unit was manufactured during the 24th week of 2019, or approximately June 2019.
Older ICP equipment may use different serial-number formats.
Many ICP model numbers contain a two- or three-digit capacity code.
Common codes include:
18 / 018 = 18,000 BTU = 1.5 tons
24 / 024 = 24,000 BTU = 2 tons
30 / 030 = 30,000 BTU = 2.5 tons
36 / 036 = 36,000 BTU = 3 tons
42 / 042 = 42,000 BTU = 3.5 tons
48 / 048 = 48,000 BTU = 4 tons
60 / 060 = 60,000 BTU = 5 tons
For example:
N4H5S36AKAAA
The 36 indicates approximately 36,000 BTU, making this a 3-ton unit.
ICP uses different model prefixes to identify different equipment families.
For example, common model families may distinguish between heat pumps, straight-cool air conditioners, package units, and indoor equipment.
Because ICP has produced equipment under numerous brands and model families over the years, the model prefix should be considered along with the complete model number rather than relying on one universal prefix rule.
Depending on the equipment, the model number may also provide information about the product series, efficiency class, refrigerant generation, electrical configuration, and equipment type.
Exact SEER or SEER2 ratings can depend on the complete matched indoor and outdoor system.
Give Ask Klein the brand, model number, and serial number exactly as they appear on the equipment label.
We’ll do the decoding for you.
Trane and American Standard systems commonly use similar model and serial number formats. These numbers can help determine the equipment’s manufacture date, nominal size, and equipment type.
On many newer Trane and American Standard systems, the serial number begins with a four-digit date code.
A common format looks like:
2315A12345
In this format:
First 2 digits = Year
Next 2 digits = Week of the year
For example:
2315A12345
23 = 2023
15 = 15th week
This unit was manufactured during the 15th week of 2023, or approximately April 2023.
Trane has used several different serial-number formats over the years, so older equipment may decode differently.
Many Trane and American Standard model numbers contain a three-digit capacity code:
018 = 18,000 BTU = 1.5 tons
024 = 24,000 BTU = 2 tons
030 = 30,000 BTU = 2.5 tons
036 = 36,000 BTU = 3 tons
042 = 42,000 BTU = 3.5 tons
048 = 48,000 BTU = 4 tons
060 = 60,000 BTU = 5 tons
For example:
4TWR4036N1000A
The 036 indicates approximately 36,000 BTU, making this a 3-ton unit.
On common Trane residential equipment, the beginning of the model number can help identify what you’re looking at.
For example:
4TWR = Heat pump
4TTR = Air conditioner / straight cool
American Standard uses corresponding model families with different prefixes.
Model prefixes have changed between product generations, so older equipment may use different designations.
Depending on the model, it may also identify the product family, efficiency class, refrigerant generation, electrical characteristics, and equipment configuration.
Exact SEER or SEER2 ratings can depend on the complete matched system, so the outdoor model number alone doesn’t always establish the final rated efficiency.
Give Ask Klein the brand, model number, and serial number exactly as they appear on the equipment label.
We’ll do the decoding for you.
York, Coleman, and Luxaire are part of the same equipment family and commonly use similar model and serial number formats. These numbers can help determine the equipment’s manufacture date, nominal size, and equipment type.
Many York, Coleman, and Luxaire systems use a serial number that contains the manufacturing date near the beginning.
A common format uses:
2nd character = Year
4th character = Month
The month is represented by a letter:
A = January
B = February
C = March
D = April
E = May
F = June
G = July
H = August
J = September
K = October
L = November
M = December
The letter I is skipped.
Because the year may be represented by only a single digit, the approximate age of the equipment is sometimes needed to determine the correct decade.
York and its related brands have also used several serial-number formats over the years, so older equipment may decode differently.
Many York, Coleman, and Luxaire model numbers contain a capacity code:
018 = 18,000 BTU = 1.5 tons
024 = 24,000 BTU = 2 tons
030 = 30,000 BTU = 2.5 tons
036 = 36,000 BTU = 3 tons
042 = 42,000 BTU = 3.5 tons
048 = 48,000 BTU = 4 tons
060 = 60,000 BTU = 5 tons
For example, a model number containing:
036
typically indicates approximately 36,000 BTU, or 3 tons of nominal capacity.
York, Coleman, and Luxaire have used numerous model families over the years. The model prefix can often identify whether the equipment is a heat pump, straight-cool air conditioner, package unit, or indoor unit.
Because the prefixes vary considerably between product generations, the complete model number is useful when identifying the exact equipment type.
Depending on the product family, the model number may also provide information about the equipment series, efficiency class, electrical configuration, staging, and generation.
Exact SEER or SEER2 ratings may depend on the complete matched indoor and outdoor system.
Give Ask Klein the brand, model number, and serial number exactly as they appear on the equipment label.
We’ll do the decoding for you.
There are a lot of HVAC manufacturers out there, and not every model or serial number follows the same format.
If your brand isn’t listed above, don’t worry.
Give Ask Klein the manufacturer, model number, and serial number exactly as they appear on the equipment label. We may still be able to help identify your system.
And if the numbers don’t tell us enough, a clear photo of the equipment data plate can usually give us more to work with.
The date encoded in a serial number is generally the manufacture date, not necessarily the date the system was installed.
Your equipment could have been installed weeks or months after it was manufactured.
So when we decode a serial number, we’re telling you when the equipment was made—not claiming that’s the exact day it went into service.
