No Amazon products are linked on this post. Central air systems are sold and installed through dealers. Standards and ratings are described in general terms, so check them with a licensed installer.
Your central AC is a big, loud box in the yard. It is also the most expensive thing between you and July. The Goodman GSX13 was the budget way to buy one. Here is what that name used to mean, what has changed and what to ask before you sign a quote.
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What the GSX13 Was
The Goodman GSX13 was an entry-level central air conditioner with a 13 SEER rating, R-410A refrigerant, a single-stage compressor and a limited warranty that gets longer if the installer registers it. Goodman sells through contractors, not through Amazon, so there is no price button on this page. The old review praised it for efficiency, easy use and a compressor built to last. Take those as the old page opinions.
Why 13 SEER Is Old News
In January 2023, the US raised the minimum efficiency for new split-system air conditioners and switched to the SEER2 test. The new floor is 13.4 SEER2 in the north and 14.3 SEER2 in the south and southwest. A 13 SEER unit tests out around 12.4 SEER2, which is below both. In plain English: the GSX13 sits under today’s minimums for most of the country. Your installer will be selling you something newer. Our SEER2 energy savings guide explains the new rating.
Refrigerant Is Changing Too
The old GSX13 used R-410A. New residential AC equipment made from 2025 on has to use lower-impact refrigerants such as R-454B or R-32. They are mildly flammable, so techs need new training and new tools. It does not mean your old R-410A system is illegal to run. It does mean the refrigerant for it will cost more over time.
What the Old Review Said
The old page called the unit eco-friendly because of its chlorine-free refrigerant, praised its efficiency, said it was easy to install and described a limited warranty that gets longer when the unit is registered, with an initial five-year term if you forget to register. It named the Amana ASX14 (14 SEER) and a Rheem Ruud 16 SEER model as the better options. Ask about warranty terms in writing. Registration deadlines are short, and forgotten registrations cost people years of coverage.
Here is where central AC is heading: higher efficiency floors, new refrigerants and more variable-speed gear. The old 13 SEER units were the entry ticket for years. Today the floor is higher, and it keeps creeping up. A cheap system is getting harder to find.
How to Size a Central AC
Rough rule: one ton, or 12,000 BTU, per 500 to 600 square feet of well-insulated floor. That varies a lot with climate, windows and ductwork. A good installer does a load calculation, called a Manual J, not a guess from the square footage. If a contractor quotes without measuring anything, find another contractor. Our BTU calculator gives a rough idea to compare against.
Quote Questions That Save Money
- What is the SEER2 of this exact system, indoor and outdoor together?
- Is it single-stage, two-stage or variable-speed?
- What refrigerant does it use?
- Is the ductwork part of the quote, and has it been tested for leaks?
- Who registers the warranty, and when?
- Is a heat pump a better fit than a plain AC for this climate?
The Installer Matters More Than the Badge
A mid-range unit installed well beats a top-shelf unit installed badly. Refrigerant charge, line length, airflow and duct sealing decide how the system performs, and a rushed crew gets those wrong. Ask how many systems the company installs a year, whether the techs are licensed and whether they test the charge when they finish. A friendly salesperson is nice. A signed commissioning checklist is better.
Cost Reality
A new central AC replacement runs from a few thousand dollars to well over ten thousand, depending on size, brand, ductwork and your region. The cheapest quote is often the one that skips a load calculation or reuses leaky ducts. Get three quotes. Throw out the highest and the lowest. Read the middle one slowly.
When to Repair Instead
If your system is under ten years old and the problem is a capacitor or a fan motor, repair is usually smarter. If it is 15 years old, uses R-22 and needs a compressor, replace it. A system that stops cooling can also be a simple fix. Read central air conditioner not cooling before you call anyone.
The downside? Complexity. New refrigerants are mildly flammable, which changes how techs install and service them. Variable-speed systems cost more to fix. Expect repair bills to grow, and parts for older systems to get scarce. If your current unit still runs fine, you are not obliged to rush, but you should know the replacement price now.
FAQ
Is the Goodman GSX13 still sold?
Ask your dealer. Efficiency rules for new split systems rose in 2023, so the current Goodman line is different from the old 13 SEER unit.
What is 13 SEER in SEER2?
Around 12.4 SEER2, which is below the new minimums of 13.4 in the north and 14.3 in the south.
Does a new AC use R-410A?
No. New equipment made from 2025 uses lower-impact refrigerants such as R-454B or R-32.
How big of an AC do you need?
Roughly one ton per 500 to 600 square feet, but only a load calculation gives the real answer.
Final Word
The GSX13 was a decent entry unit for its day. Today, ask for the SEER2 number, the refrigerant and the warranty in writing. Then compare it with the Goodman GSX16 review and the Rheem Ruud 3-ton review before you sign.
What happens next: expect more heat pumps taking the place of straight AC, more rebates for efficient models and more installers who only quote new-standard equipment. Ask for the SEER2 number in writing.
Related Guides
Keep going with Goodman GLXS4BA4210 review, Goodman GSX16 review, Rheem Ruud 3-ton review, SEER2 energy savings guide and central air conditioner not cooling.
Featured photo: “Condenser unit for central air conditioning” by H Padleckas, CC BY-SA 3.0, via Wikimedia Commons (cropped).
