HVAC Model Number Lookup
Type the model number off your data plate and we’ll read the nominal tonnage, the brand family, and roughly how old the system is — free, no sign-up, no email.
Read the tonnage, brand family and approximate age off any model number
READ THIS BEFORE YOU CALL
This lookup is a free reference tool, here for you to use on your own. Open To Public HVAC Parts is a walk-in parts counter in Dallas, Texas.
- We cannot decode model numbers over the phone or by email.
- The data plate is always the authority — this reads industry conventions, not a manufacturer database.
If you are local, bring the old part or a photo of the plate to 10226 Plano Rd, Suite 104, Dallas TX and we will read it and match it free at the counter.
Off the data plate. Letters and numbers, no spaces — e.g. GSX140361, 24ACC636A003, 4TTR6036J1000A
Same plate, usually just below the model.
The thing most people get wrong about tonnage
“5 ton” is a size class, not a measurement. The number in your model gives you the nominal rating — what it’s sold as. It is not necessarily what the system actually delivers.
We’ve seen 5 ton 14 SEER units built on a 54,000 BTU compressor that AHRI-match out above 60,000 BTU of cooling. We’ve also seen 5 ton 16 SEER units built on a 42,000 BTU compressor that only reach about 50,000. Both are sold as “5 ton.” That’s a full ton of real capacity between them, and nothing on the quote tells you which one you’re getting.
A nominal 3 ton absolutely can deliver 3 tons — with the right coil and air handler match, from the right brand. The point isn’t that the number is meaningless. It’s that the number alone doesn’t tell you, and the outdoor unit is only half the equation.
If you’re buying a system, ask for the AHRI certified match number, not just the tonnage. That’s the figure that tells you the real rated capacity of the condenser, coil and air handler working together.
Where to find your data plate
| Equipment | Where the plate is |
|---|---|
| Condenser (outdoor unit) | On the side or back of the cabinet, usually near the service valves where the copper lines connect. |
| Furnace | On the interior wall, usually upper right, in the same compartment as the burners and inducer. Not on the door panel. |
| Air handler | On the outside of the cabinet, like a sticker. Not inside the access panel — that’s where the furnace plate lives. |
| Evaporator / cased coil | Its own sticker on the coil housing. |
Take a photo of the whole plate rather than writing the number down. Plates are stamped, faded and badly lit, and a 6 that’s really a 5 sends you home with the wrong part.
How the capacity number works
Most manufacturers put the nominal capacity in the model as a three-digit code in thousands of BTU:
| Code in model | BTU/hr | Nominal tons |
|---|---|---|
018 | 18,000 | 1.5 |
024 | 24,000 | 2 |
030 | 30,000 | 2.5 |
036 | 36,000 | 3 |
042 | 42,000 | 3.5 |
048 | 48,000 | 4 |
060 | 60,000 | 5 |
Furnaces are different — those numbers are usually input BTU (like 060, 080, 100, 120) and often a separate two-digit airflow figure in CFM hundreds.
Common questions
What size is my AC unit?
The nominal size is encoded in the model number of the outdoor condenser, almost always as a number in thousands of BTU: 018 is 1.5 ton, 024 is 2 ton, 030 is 2.5, 036 is 3, 042 is 3.5, 048 is 4 and 060 is 5. Twelve thousand BTU equals one ton. Furnace model numbers carry heating input instead, so a furnace will not tell you your cooling size — read the outdoor unit.
How can I tell how old my AC unit is?
The age is in the serial number, and the format depends on the manufacturer. Goodman, Amana and Daikin serials read year then month, so 1805 is May 2018. Carrier, Bryant and Payne read week then year. Trane serials since 2002 read year then week. Several brands use plant or letter codes that changed between eras, which is why this tool declines to guess rather than give you a wrong year.
Where is the data plate on my AC unit?
On the outdoor condenser it is on the side or back of the cabinet, usually near the service valves where the copper lines connect. On a furnace it is on the interior wall, upper right, in the same compartment as the burners — not on the door panel. On an air handler it is a sticker on the outside of the cabinet. Photograph the whole plate rather than copying the number by hand.
Does a 3-ton unit actually deliver 3 tons of cooling?
Not necessarily. Nominal tonnage is a size class, not a measurement. We have seen units sold as 5 ton built on compressors ranging from 42,000 to 54,000 BTU, which AHRI-match anywhere from about 50,000 to over 60,000 BTU depending on the coil and air handler paired with them. If you are buying a system, ask for the AHRI certified match number rather than the tonnage.
Can you decode my model number over the phone?
No. We are a walk-in counter and we cannot read a plate we cannot see. Bring the part or a photo of the data plate to 10226 Plano Rd, Suite 104 in Dallas and we will read it, find what replaces it, and test your old part free at the counter.
Once you know what you’ve got
Most of what fails on a running system is a part we keep on the shelf. Match yours here:
- Capacitor cross-reference — match a run or start capacitor by MFD, voltage and OEM part number.
- Contactor cross-reference — pole count, coil voltage and amp rating.
- Condenser and blower motor cross-reference — HP, RPM, frame and rotation.
- Hot surface ignitor cross-reference
- Control board cross-reference
- All troubleshooting guides and lookup tools
- Browse the catalog — live counter stock and in-store pricing.
Bring us the part. We’ll test it free.
Bring the old part or a photo of the data plate. We’ll work out what it is, find the replacement, and meter the old one at the counter before you buy anything. No purchase needed.