ManualHarbor

Central Air Conditioner Installation Cost

Updated October 9, 2026

Replacing a central air conditioner on existing ducts that are in good shape typically costs $5,500 to $10,000 for a 3-ton system, according to Fixr, and This Old House's October 2026 guide puts the average central AC installation at $8,460, with a range of $6,345 to $10,575. Needing new ductwork changes the math: Fixr estimates $8,650 to $20,200 for a 3-ton unit with new ducts in a 2,000-square-foot home. System size, SEER2 tier, your region's federal efficiency minimums and the refrigerant changeover all show up in the quote.

Central AC cost at a glance

  • This Old House (updated Oct. 2, 2026) — Scope: Central AC including installation; Homewyse estimates plus a 2026 survey of 1,000 homeowners; Figure: $6,345–$10,575; average $8,460
  • Fixr (updated Aug. 29, 2025) — Scope: National range; the average assumes a 3-ton, 16 SEER split system with new ductwork in a 2,000 sq. ft. home; Figure: $5,800–$14,400; average $8,750
  • NerdWallet (updated Oct. 1, 2025) — Scope: Unit plus labor; Figure: About $6,000–$11,500; unit alone $2,500–$4,500

Fixr's extremes show how much scope matters: $3,750 for a 3-ton, 14 SEER change-out on existing ducts, versus $18,000 for a new 21 SEER, 3-ton installation with 300 feet of new ducts and custom work.

Existing ducts vs. new ductwork

  • Replace AC, keep existing ducts — Fixr estimate: $5,500–$10,000
  • Replace AC with partial or full duct replacement — Fixr estimate: $7,500–$16,000
  • New ductwork alone in a retrofit (labor and material) — Fixr estimate: $3,600–$9,500
  • New AC plus new ducts in a 2,000 sq. ft. home — Fixr estimate: $8,650–$20,200
  • Older house with 180–300 feet of new ducts — Fixr estimate: $8,650–$22,000

Source: Fixr central AC installation cost guide (updated August 29, 2025).

NerdWallet's duct figures point the same way: $2,000–$7,500 to install ducts in a home without them or to replace them entirely, and $300–$1,000 for minor repairs. Fixr explains why retrofits cost more: new ducts have to be routed through closets, under stairs and other spaces not designed for them, and it says retrofit duct labor can run nearly three times the labor of replacing existing ducts.

Existing ducts aren't automatically ready for a new system. Bryant lists resizing, repairing or insulating ducts among the cost drivers, and NerdWallet notes that ducts may need an upgrade to handle a new unit's airflow. Duct condition also affects running costs: Energy.gov has noted that duct losses can exceed 30% of space-conditioning energy when ducts run through unconditioned spaces such as attics.

Price by size

  • 1.5 tons — Cooling capacity: 18,000 Btu/h; Fixr installed (materials only): $3,650–$6,250 ($2,400–$4,250); This Old House average: $8,448
  • 2 tons — Cooling capacity: 24,000 Btu/h; Fixr installed (materials only): $4,250–$7,500 ($3,000–$5,500); This Old House average: $8,551
  • 2.5 tons — Cooling capacity: 30,000 Btu/h; Fixr installed (materials only): $4,500–$8,000 ($3,300–$6,000); This Old House average: $8,586
  • 3 tons — Cooling capacity: 36,000 Btu/h; Fixr installed (materials only): $5,000–$9,150 ($3,800–$7,150); This Old House average: $8,654
  • 3.5 tons — Cooling capacity: 42,000 Btu/h; Fixr installed (materials only): $5,450–$9,700 ($4,250–$7,700); This Old House average: $8,723
  • 4 tons — Cooling capacity: 48,000 Btu/h; Fixr installed (materials only): $6,950–$11,600 ($5,750–$9,600); This Old House average: $13,136
  • 5 tons — Cooling capacity: 60,000 Btu/h; Fixr installed (materials only): $7,800–$14,000 ($6,600–$12,000); This Old House average: $16,312

Sources: Fixr (mid-efficiency units; updated August 29, 2025); This Old House air conditioner cost guide (updated October 2, 2026), whose ranges by size are very wide, for example $5,026–$19,051 at 3 tons. Capacity is cooling output at 1 ton = 12,000 Btu/h, not electrical input.

Four- and 5-ton units sit at or above 45,000 Btu/h, which puts them in a separate class under the federal regional standards described below.

Price by SEER2 tier

  • 14 / 13.4 — 3-ton unit only: $1,725–$3,600
  • 15 / 14.3 — 3-ton unit only: $2,300–$4,800
  • 16 / 15.3 — 3-ton unit only: $2,875–$6,000
  • 17 / 16.2 — 3-ton unit only: $3,450–$6,600
  • 18 / 17.2 — 3-ton unit only: $4,100–$7,800
  • 19 / 18.1 — 3-ton unit only: $4,600–$8,400
  • 20 / 19.1 — 3-ton unit only: $5,750–$9,600
  • 21 / 20 — 3-ton unit only: $6,325–$10,800

Source: Fixr (updated August 29, 2025); equipment only, before labor. Fixr says SEER2 numbers run about 4.5% lower than old SEER numbers, but DOE cautions that the two metrics are not directly comparable, so compare SEER2 with SEER2.

Example: is a higher SEER2 tier worth it?

Example with stated assumptions; replace them with your own numbers.

  • Capacity: 3 tons = 36,000 Btu/h of cooling output
  • Use: 1,000 equivalent full-load cooling hours per year (an assumption; hot climates run far more, mild ones less)
  • Electricity: 18.19¢ per kWh, the U.S. residential average for January–July 2026 (EIA)

SEER2 is a ratio of cooling delivered (Btu) to electricity used (watt-hours) over a season, so:

Annual kWh = (36,000 Btu/h × 1,000 h) ÷ SEER2 ÷ 1,000 Wh per kWh

  • At 14.3 SEER2: 36,000,000 ÷ 14.3 ÷ 1,000 ≈ 2,517 kWh, or about $458 a year
  • At 17.2 SEER2: 36,000,000 ÷ 17.2 ÷ 1,000 ≈ 2,093 kWh, or about $381 a year
  • Difference: about 424 kWh, or roughly $77 a year

In Fixr's unit-only table, moving from 14.3 to 17.2 SEER2 raises the 3-ton unit price from $2,300–$4,800 to $4,100–$7,800. At $77 a year that premium pays back slowly; with twice the cooling hours or a higher rate from your own bill, the case gets stronger. SEER2 is a standardized test rating, so real savings also depend on installation quality and how you use the system.

The 2023 DOE regional efficiency standards

Since January 1, 2023, central air conditioners must meet SEER2-based minimums that vary by region, according to DOE's 2023 standards FAQ.

  • Under 45,000 Btu/h, minimum SEER2 — North: 13.4; Southeast: 14.3; Southwest: 14.3
  • Under 45,000 Btu/h, minimum EER2 — North: none; Southeast: none; Southwest: 11.7 (9.8 if SEER2 is 15.2 or higher)
  • 45,000 Btu/h and up, minimum SEER2 — North: 13.4; Southeast: 13.8; Southwest: 13.8
  • 45,000 Btu/h and up, minimum EER2 — North: none; Southeast: none; Southwest: 11.2 (9.8 if SEER2 is 15.2 or higher)

The Southwest is Arizona, California, Nevada and New Mexico. The Southeast covers Alabama, Arkansas, Delaware, Florida, Georgia, Hawaii, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, the District of Columbia, Puerto Rico and the other U.S. territories. All other states are in the North. Single-package air conditioners must meet 13.4 SEER2 nationwide, plus 10.6 EER2 in the Southwest.

Enforcement differs by region. In the North, the rule follows the date of manufacture, so a unit built before 2023 to the old standard can still be installed. In the Southeast and Southwest, it follows the installation date, and DOE says it is illegal for a contractor there to install a unit that doesn't meet the regional standard. Fixr attributes a roughly 15%–20% rise in HVAC system prices to the 2023 change.

Refrigerant transition: R-410A to A2L refrigerants

EPA's restrictions table (last updated August 28, 2026) limits new residential and light commercial air conditioning and heat pump systems, including mini splits and unitary systems, to refrigerants with a global warming potential (GWP) of 700 or less, with a January 1, 2025, installation compliance date. Following EPA's reconsideration rule issued May 26, 2026, the table shows no installation compliance date for systems whose specified components were all manufactured or imported before January 1, 2025. Older articles that cite a January 1, 2026, cutoff for installing R-410A systems predate that change. Components used to repair existing systems are not subject to these restrictions.

EPA's SNAP listings give R-410A a GWP of 2,090, compared with 470 for R-454B and 675 for R-32; both replacements are A2L (lower-flammability) refrigerants accepted with use conditions. Carrier, which sells R-454B as Puron Advance, lists its GWP as 466 versus 2,088 for R-410A, says its products include a leak detection system that runs a fan to disperse refrigerant, and states that R-454B cannot be used as a direct replacement for R-410A in an existing system.

What that means for your quote:

  • Ask which refrigerant the quoted system uses.
  • If it's R-410A, ask the contractor to confirm that every component predates January 1, 2025.
  • Choose an installer familiar with A2L equipment, as Carrier recommends.

Sizing: why Manual J matters

ACCA's Manual J is the ANSI-recognized standard for calculating a home's heating and cooling loads, and ACCA says a Manual J load calculation is required by national building codes and most state and local jurisdictions. ENERGY STAR says your contractor should verify system size with Manual J, because a system that is too large or too small will struggle to keep the home comfortable. NerdWallet says many contractors run the calculation for free or include it in the estimate, while a separate pre-installation evaluation can cost $300–$900. Be wary of a bid that simply matches the old unit's tonnage or relies on square footage alone.

What a quote should include

Bryant's central AC cost page lists typical inclusions: the outdoor unit, evaporator coil and air handler or furnace interface; a refrigerant line set, replaced or reused as appropriate; an equipment pad; permits and inspections; a thermostat; installation, startup and testing; removal of the old equipment; and manufacturer and contractor warranties. It says major duct redesigns, panel upgrades or significant electrical work, structural changes and optional upgrades are often excluded unless listed. Fixr notes the existing pad may be reused if it's in good condition, puts removal and disposal of the old unit at $150–$250, and says installers typically charge $75–$250 an hour. New circuits or panel work belong with a licensed electrician.

Considering a heat pump instead

A ducted heat pump uses the same split-system layout as central air but also heats. DOE's nationwide minimum for new split-system heat pumps is 14.3 SEER2 and 7.5 HSPF2, and Fixr prices a ducted air-source heat pump at $5,000–$15,000 installed. ManualHarbor doesn't list central air conditioner models, but you can compare ENERGY STAR certified heat pumps, including ducted split systems. A new system is also a natural time to add a smart thermostat.

FAQ

How much does a 3-ton central AC cost to install?

Fixr puts a mid-efficiency 3-ton installation at $5,000–$9,150, or $5,500–$10,000 as a replacement on existing ducts. This Old House's 3-ton average is $8,654.

Can contractors still install R-410A air conditioners?

According to EPA's current restrictions table, only if all specified components of the system were manufactured or imported before January 1, 2025. Repairs to existing R-410A systems aren't restricted.

What SEER2 rating do I need?

At minimum, whatever DOE requires for your region and unit size: 13.4 SEER2 in the North, and 14.3 SEER2 in the Southeast and Southwest for units under 45,000 Btu/h, plus an EER2 minimum in the Southwest. Above that, the payoff depends on your cooling hours and electricity rate; run the example above with your own numbers.

Is there a federal tax credit for a new central AC?

Not for systems installed now. The IRS says the Energy Efficient Home Improvement Credit covers improvements made through December 31, 2025, and its FAQ says the credit isn't allowed for property placed in service after that date. Check the ENERGY STAR Rebate Finder and your utility for local rebates.

Related guides

Sources