2.5-Ton Central Air Conditioners: Which One to Buy

Is 2.5 tons the right size?

Replacing a unit? Match the old one. On most outdoor units the size is in the model number: 30 means 2.5 tons (Goodman's GLXS4BA3010 is a 2.5-ton). The common rule of thumb is one ton per 400 to 500 sq ft, about 1,000 to 1,250 sq ft for 2.5 tons. The U.S. Department of Energy warns that rule ignores your climate and insulation, and recommends a contractor's load calculation (Manual J). Other sizes: 2 ton · 3 ton · 4 ton.

What it costs

Amazon prices read today. Installed prices are U.S. typical for a replacement on existing ductwork, equipment, labor and permit together, from EnergySage, Modernize and other published 2026 data (compiled July 2026). Buying the unit yourself still leaves the installer's labor, refrigerant work and permit to pay.

Before you order one online

1. Book the installer first. Goodman gives no warranty on equipment bought online unless a licensed dealer installs it to code. Ask whether they will fit a unit you supply. Charging the refrigerant needs EPA Section 608 certification.
2. Check your region. A 13.4 SEER2 unit is allowed only in the North. In the Southeast and Southwest buy 14.3 SEER2 or higher at this size.
3. Match the coil. The rating is for an outdoor unit and coil together. Buy them as a system, or have the installer confirm your coil matches.
4. Match the size. Read the size in your old outdoor unit's model number, unless the house has changed a lot.

Every 2.5-ton central AC we matched on Amazon (1)

2.5-ton central AC on Amazon: what is in the box, certified SEER2 range, region and price

Unit	In the box	SEER2 (AHRI)	Where allowed	Price	Buy
Goodman GLXS4BA3010	Outdoor unit only	14.3–15.5	Every region	$1,999	Buy

SEER2 is the certified AHRI range for that outdoor unit with Goodman's own coils (for a system, with the coil in the box). Prices read live on Amazon today.

Questions buyers ask

How many square feet does a 2.5 ton AC cool?

The common rule of thumb is one ton per 400 to 500 sq ft, so about 1,000 to 1,250 sq ft. The U.S. Department of Energy warns that rule ignores your climate and how well the house is built, and says a contractor's load calculation (Manual J) is the real answer. When you replace a unit, match the size of the old one.

How much does a 2.5 ton AC unit cost?

On Amazon, $1,999 to $1,999 for the 1 Goodman listings here (the outdoor unit alone, or with its coil). Installed by a contractor, a 2.5-ton central AC typically runs $4,500 to $8,000, equipment and labor together.

Can I buy a central AC online and keep the warranty?

Yes, if a licensed dealer installs it. Goodman says it gives no warranty on equipment a homeowner buys online unless the unit is installed by a dealer who follows all federal, state and local codes and licensing rules. Line up the installer before you order.

Can I install a central AC myself?

No. Connecting and charging the refrigerant lines is work for a licensed installer, and in the U.S. it needs EPA Section 608 certification. Goodman's warranty also depends on a licensed install.

Is a 13.4 SEER2 AC legal where I live?

Only in the North region. Since January 1, 2023 the federal floor for split central AC is 13.4 SEER2 in the North and 14.3 SEER2 at this size in the Southeast and Southwest (the Southwest also sets an EER2 floor). Goodman sells its GLXS3BN units as North-region only.

Outdoor unit only, or with the coil?

A system with its matched coil is what the rating on the listing assumes. An outdoor unit alone only makes sense if your installer confirms your existing coil matches it; the certified rating changes with the coil it is paired with.