The model number on your outdoor unit tells you more than most people expect. On current Goodman condensers and heat pumps, it shows whether the unit is an air conditioner or a heat pump, single or two-stage, roughly how efficient it is, which DOE regions it can be installed in, and its size in tons.
Indoor coils have their own code, and it’s just as useful. Here’s how to read both.
Where to find the model number
On the outdoor unit, look for a metal or sticker data plate on the side of the cabinet. It’s often near the electrical panel or the copper line connections. Sun and weather fade these labels, so a phone photo with the flash on can pick up what your eyes miss.
For the indoor coil, look on the coil cabinet itself, which usually sits right on top of or below the furnace or inside the air handler. If the coil is uncased and buried in a plenum, your installer may have to find it.
Grab the serial number while you’re there. It’s on the same label and you’ll need it for warranty questions.
Decoding a Goodman condenser or heat pump
Example: GLXS4BA3610, a Goodman R-32 air conditioner.
| Position | In the example | What it means |
|---|---|---|
| 1 | G | Brand: Goodman |
| 2 | L | Split system, R-32 refrigerant |
| 3 | X | Type. X = air conditioner (condenser). Z = heat pump. |
| 4 | S | Compressor. S = single-stage. T = two-stage. |
| 5 | 4 | SEER2 efficiency band. Goodman lists 4 as 13.8 to 14.5 SEER2. Higher digits mean higher efficiency. |
| 6 | B | Series. B = standard. M = multi-family. C = communicating. |
| 7 | A | DOE region. N = North only. S = Southeast and North. A = all regions. |
| 8-9 | 36 | Nominal capacity in thousands of BTU/h. 36 = 36,000 BTU/h = 3 tons. |
| 10 | 1 | Electrical: 208/230 volt, single phase, 60 Hz |
| 11 | 0 | Variation code |
| After that | (A, B…) | Revision letters, when shown |
Change one letter and you have a different product. GLZS4BA3610 is the heat pump version: same layout, but the Z in position 3 means it heats as well as cools.
Position 7 is the one to pay attention to if you live in the South. An N unit can only be installed in North states. Our guide to DOE regional efficiency standards lists which states are in each region.
Goodman’s variable-speed side-discharge units follow a slightly different layout (they start GXV or GZV), but the capacity digits work the same way.
Finding the tonnage
This is the question we get most. Look for a two-digit number in the model, usually from 18 to 60, and divide by 12. One ton of cooling is 12,000 BTU per hour.
| Digits | BTU/h | Tons |
|---|---|---|
| 18 | 18,000 | 1.5 |
| 24 | 24,000 | 2 |
| 30 | 30,000 | 2.5 |
| 36 | 36,000 | 3 |
| 42 | 42,000 | 3.5 |
| 48 | 48,000 | 4 |
| 60 | 60,000 | 5 |
Older units and other brands use the same idea. You might see something like 036 or 36 buried in the middle of the model. If the number you find doesn’t land on one of the sizes above, it’s probably something else, so send us a photo.
Residential split systems top out at 5 tons. Bigger homes often end up with two systems, one per floor or zone.
Decoding a Goodman indoor coil
Example: CAPTA3626B3, a cased R-32 evaporator coil.
| Position | In the example | What it means |
|---|---|---|
| 1 | C | Indoor coil |
| 2 | A | Application. A = upflow/downflow. H = horizontal. S = horizontal slab. |
| 3 | P | Cabinet. P = cased, painted. C = cased, unpainted. U = uncased. |
| 4 | T | Metering device. T = TXV (thermal expansion valve). F = flowrator (fixed orifice). E = electronic expansion valve. |
| 5 | A | Series letter |
| 6-7 | 36 | Nominal capacity: 36 = 3 tons |
| 8-9 | 26 | Coil height in inches (on upflow/downflow coils) |
| 10 | B | Cabinet width. A = 14 in, B = 17.5 in, C = 21 in, D = 24.5 in. |
| 11 | 3 | Refrigerant: 3 = R-32 |
A CHPTA coil reads the same way at the start: C for coil, H for horizontal, P for painted, T for TXV. Horizontal coils use the size digits for their own dimensions, so check the spec sheet for exact measurements before you plan the install.
Why the coil code matters
The width letter should match your furnace. Goodman uses the same A through D letters for furnace cabinets, so a B-width furnace pairs naturally with a B-width coil. Our guide on reading a furnace model number shows where that letter sits on the furnace side.
The refrigerant digit matters even more. An R-32 condenser needs a coil built for R-32. You can’t reuse an old R-410A coil with a new R-32 outdoor unit.
The system rating comes from the match
The SEER2 band in the condenser model is a range. The actual rating depends on which coil, and sometimes which furnace or air handler, it’s paired with. These pairings are listed in the AHRI directory, and the matched rating is what counts for regional rules and for most rebates.
That’s why we sell matched systems. Every combination in our system selector is built from parts meant to go together, and you can see your price in the cart.
Common questions
How do I tell what size my AC is from the model number?
Find the two-digit number between 18 and 60 and divide by 12. A 36 is 3 tons, a 48 is 4 tons, a 60 is 5 tons, and a 24 is 2 tons.
What is the difference between GLXS4 and GLZS4?
The third letter. X means air conditioner, Z means heat pump. Otherwise the layout of the model number is the same.
What does the N, S or A in a Goodman condenser model mean?
It’s the DOE region the unit can be installed in. N is North only, S is Southeast and North, and A is all regions, including the Southwest.
Can I put a new condenser on my old indoor coil?
Not if the refrigerants differ. A new R-32 condenser needs a coil rated for R-32. Even when refrigerant matches, a mismatched pair can fall below the efficiency rating you’re paying for.
Can’t make sense of your label? Call (877) 843-4822 and read it to us, or browse central air conditioners.