# Determining Air Conditioning Age & Capacity-Reprinted

By
Home Inspector with JaxHomeSpy, LLC
https://activerain.com/droplet/4hBx

Determining Air Conditioning Age & Capacity

As a rule-of-thumb, capacity information is encoded by air conditioning

manufactures in the model number and date of manufacture info in the serial number.

There are 12,000 Btus per ton of cooling, and air conditioners are sized by every

½ ton. Manufacturers often encode the approximate rating in Btus somewhere in the

model number. Therefore it is often simple to scan the model number for a two-digit

number that is divisible by 6 and to divide it by 12 to determine the capacity rating in

tons. This number can be elusive, as it is not always exactly divisible by 6. Some

manufacturer's systems make this easier than others. To complicate matters, some

manufacturers have changed their systems of encoding data over time.

Amana

Age: Use B-L-A-C-K H-O-R-S-E code

B = 71 or 81

L = 72 or 82

A = 73 or 83

C = 74 or 84

K = 75 or 85

H = 76 or 86

O = 77 or 87

R = 78 or 88

S = 69, 79 or 89

E = 70, 80 or 90

________________________________________________________________________

Bryant

Capacity: Look for those elusive two digits in the model number usually (but not always)

divisible by 6 and divide by 12 to convert to tons.

Example: 56BAB0042000A0

42 = size on thousands of BTU

42,000 Btu = 3½ ton

From 1964 through 1979 Bryant encoded age information in the

serial number with the first two digits indicating week of

manufacture and the letter following those first two numbers

indicating the year beginning R = 1964:

R = 1964

S = 1965

T = 1966

U = 1967

V = 1968

W = 1969

X = 1970

Y = 1971

A = 1972

B = 1973

C = 1974

D = 1975

E = 1976

F = 1977

G = 1978

H = 1979

In subsequent years Bryant simplified its system where, the first two digits of serial

number = Week of manufacture.

Third & fourth digits = Year of manufacture.

Example: 3188XXXXXX = 31st week of 1988.

Carrier

Carrier has used several different codes at different plants. Information below refers to

commonly used codes.

Capacity: Commonly found in the last three to five digits of model number, sometimes

in 100s of Btus - sometimes in tons

Example:

001 = 1.5 ton, 002 = 2 ton, 003 = 2.5 ton, 004 = 3 ton, 004-5 = 3.5 ton,

005 = 4 ton, 006 = 5 ton

Or

18xx = 1.5 ton, 24xx = 2 ton, 30xx = 2.5 ton, 36xx = 3 ton, 42xx = 3.5 ton,

48xx = 4 ton, 60xx = 5 ton

Or

14xx = 1 ton, 18xx = 1.5 ton, 024 = 2 ton, 030 = 2.5 ton, 036 = 3 ton,

042 = 3.5 ton, 048 = 4 ton, 060 = 5 ton

Age: Through the 1960s Carrier used the first digit of the serial number to indicate the

year of manufacture. Example: 3xxxxx = 1963, 4xxxxx = 1964, 5xxxxx = 1965, etc.

Beginning in 1970 Carrier began to use a letter followed by a single

digit year.

Example: A1 = January 1971, B2 = February 1972,

M5 = December 1975

Note: No letter I

A=Jan

B=Feb

C=Mar

D=Apr

E=May

F= Jun

G= Jul

H=Aug

J=Sept

K=Oct

L=Nov

M=Dec

More recently Carrier has simplified things using the first four digits of the serial number

to signify the age, where the first two digits indicate the week and the third and fourth

digits indicate the year of manufacture (similar to Bryant).

Example: 3298xxxxxx = 32nd week of 1998

________________________________________________________________________

Chrysler Air Temp

Capacity: Rating in tons found in the fourth and fifth

digits of the model number

0 = 1 -1.5 ton

2 = 2 ton

3 = 2.5 ton

4 = 3 ton

5 = 4 ton

6 = 5 ton

Example: xx06xxxx = 5 ton

Climatrol

Capacity: Look for those elusive two digits in the model number (usually, but not

always) divisible by 6 and divide by 12 to convert to tons. It is often in the last three to

five digits, but is sometimes closer to the middle.

________________________________________________________________________

Coastline

Capacity: Look for those elusive two digits in the model number (usually, but not

always) divisible by 6 and divide by 12 to convert to tons. It is often in the last three to

five digits, but is sometimes closer to the middle.

________________________________________________________________________

Coleman

Coleman has used several different codes at different plants. Information below refers to

some commonly used codes.

Capacity: Commonly found in the third and fourth digits of the model number -

sometimes in 100s of Btus and sometimes as tons.

Example: xx30 = 2.5 ton, xx48 = 4 ton

or

xx02 = 2 ton, xx05 = 5 ton

________________________________________________________________________

Day-Night - Later manufactured as "BDP" (Bryant, Day-Night, Payne)

Capacity: Look for those elusive two digits in the model number (usually, but not

always) divisible by 6 and divide by 12 to convert to tons. It is often in the last three to

five digits, but is sometimes closer to the middle.

Age: First two letters of the serial number indicate age, where the

first letter is the month and the second letter the year of manufacture

beginning with 1970

A=1970

B=1971

C=1972

Etc.

Fedders

Capacity: Last two digits of the model number indicate 1000s of Btus

Example: CF30 = 2.5 ton

Age (through 1977): Last two letters of serial number

indicate month & year beginning with September 1966

Note: I not used

A=Sept

B=Oct

C=Nov

Etc.

A= 1966

B=1967

C=1968

Etc.

Example: xxxxAA = September 1966, xxxxBC = October 1968

________________________________________________________________________

General Electric

Capacity: Last three digits of model number indicate approximate rating in 1000s of Btus

Example: 21TC030A = 2.5 ton

Age: Last three digits of serial number indicate date of manufacture, where the first digit

indicates the year and the second and third indicate the week

Example: xxxxxx241 = 41st week of 1982

________________________________________________________________________

Lennox

Capacity: Lennox has its own code found between hyphens in the

model number

211=1.5 ton

261=2 ton

311=2.5 ton

411=3 ton

461=3.5 ton

511=4 ton

651=4.5 ton

Example: CHP16H-261-1P = 2 ton

Age: Prior to 1974 the first three digits of the serial number indicate the date of

manufacture where the first two digits indicate the year and the third is the month.

Example: 732xxxx = February 1973

Beginning in 1974 the third and fourth digits indicate the year followed by a

letter indicating the month.

Note: I not used

A=Jan

B=Feb

C=Mar

Etc.

________________________________________________________________________

Rheem or Ruud

Capacity: Look for those elusive two digits in the model number (usually, but not

always) divisible by 6 and divide by 12 to convert to tons.

Example: RPGC-037JA = 3 ton

Age: Four digits of serial number indicate date of manufacture where first two indicate

the week and the third and fourth are the year. In the 1960s and early ‘70s this was the

last four digits. More recently date of manufacture information is found closer to the

middle of the serial number.

Example: xxxx1872 = 18th week of 1972

________________________________________________________________________

Tappan

Capacity: Look for those elusive two digits in the model number (usually, but not

always) divisible by 6 and divide by 12 to convert to tons.

Example: CM36-11B,T = 3 ton

________________________________________________________________________

Trane

Capacity: Trane has used a number of different methods for encoding capacity

information in the model number. It is commonly found in the first three digits -

sometimes and Btus, sometimes as tons.

Example: SPCC-B504-A = 5.0 ton,

Or

TWS748A = 48,000 Btu = 4 ton

Age: Through the seventies date of manufacture information is found

as a number and a letter in the serial number where the number is the

single digit year and the letter indicates the month.

A=Jan

B=Feb

C=Mar

Etc.

Example: 1C-xxxx = March 1971

In the early ‘80s Trane began to stamp the date of manufacture in the lower right hand

corner of the data plate.

________________________________________________________________________

Whirlpool

Capacity: Look for those elusive two digits (often the first two digits) in the model

number (sometimes, but not always) divisible by 6. Divide by 12 to convert to tons.

Age: Date of manufacture information is encoded in the serial number

where a letter indicates the decade and the third and fourth digits indicate

the week.

G=1970s

H=1980s

Example: H43571485 = 35th week of 1984

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603,908
Brian Schulman
Coldwell Banker Residential Brokerage, Lancaster PA - Lancaster, PA
Lancaster County PA RealEstate Expert 717-951-5552
Mike, this much detail only emphasizes why I'll call a specialist to analyze the situation when I need it!
Aug 20, 2007 12:16 PM #1
Rainmaker
681,544
James Quarello
JRV Home Inspection Services, LLC - Wallingford, CT
Connecticut Home Inspector

Mike,

I have never understood the need for a home inspector to determine the size of an A/C compressor unit. It really has nothing to do with the home inspection. Determining the correct size of a cooling system for a particular home is a somewhat complicated process that should be left to the experts. Simply taking a size off the data plate and then rendering some opinion on its' adequacy, to me seems ridiculous.

I had the opportunity to demonstrate this fact to a fellow inspector not long ago when he invited me along to help on a large house that was being used as office space. I noticed he was checking data plates for the size of the units. I asked him if he was checking the maximum ampacity for the circuit breaker.

He replied no he does not check the maximum ampacity or the wiring in the service disconnect behind the unit.

I told him he should go check the disconnect box for the unit around the corner.

He went and looked in the disconnect box. This is what he saw.

Notice the "Fuses" are two lengths of copper plumbing pipe. The groung wire from the unit was also disconnected. The breaker inside the main panel as I recall was over-sized for the unit according to the data plate.

This is a fire or an electric shock hazard waiting to happen.

So next time your looking at the A/C compressor data plate, take a moment to note the maximum circuit breaker size and compare it to what is actually in the service panel. And open that service disconnect box, you never know what you might find.

Aug 20, 2007 01:01 PM #2
Rainer
27,874
Darrel Quebedeaux
Evergreen Realty & Associates Inc. - Newport Coast, CA
HUH???  Never mind.
Aug 20, 2007 06:52 PM #3
Anonymous
Doug

Though there is no place in the report system my co. uses, I usually check the max breaker size & find mostly in older homes the original 40 amp (typical) breaker was not downsized for the more efficient systems that will use say 25 0r 30 amp max.  I always list age & size in my report but never try to determine adequacy. (many a/c techs don't either)  Most hvac techs leave air leaks on cabintes as where lines exit & plenum attaches. Also leaks at ceiling registers, junk in drain pans, & so on. Keeps me busy...

Itsa 20/80 world, Doug

Nov 10, 2009 08:44 AM #4
Rainer
10,161
D. Spencer
Pacific Northwest Inspections Group,LLC - Seattle, WA
Bellevue Kirkland Home Inspection - Seattle, WA

James,

In new construction the inspectors should determain the seers to make sure it meets current effeiency standards..at least the good inspectors do.

Jan 29, 2010 02:22 PM #5
Rainmaker
681,544
James Quarello
JRV Home Inspection Services, LLC - Wallingford, CT
Connecticut Home Inspector

To D. Spencer,

Checking SEER, EER or HSPF is relative information in that it depends on when the unit was manufactured. I have found 11 SEER compressors on new homes that were manufactured before the federally mandated change in January 2006. Not an issue. So really how would a 10 SEER unit be a problem in a home. There is no code or regulation, at least here in CT, that would prevent an installer from putting in a lower SEER unit that was manufactured before the change date. I would classify the SEER information as nice to know, but it would certainly not be a "defect".

Jan 29, 2010 10:34 PM #6
Rainer
1,025
Brian Campbell

Superb.I have shifted to old house and there was air conditioner already fitted into it of Airdexinc but could not make out how old it is.This trick will help me out.

Feb 10, 2016 07:35 PM #7
Anonymous
Melissa

I am trying to discover the age of my central unit .... It is a Payne - model numberPA10JA036-A

Jun 29, 2016 03:16 PM #8
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## Mike Jewett

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