New air conditioning installation costs in 2026 range from $3,500 to $7,500 for most residential central AC systems, with the national average around $5,500.
AC Unit Sizing and Cost
The size of your air conditioning unit, measured in tons, is the primary factor affecting cost. Most homes require 1.5–5 tons of cooling capacity. A 1,500 sq ft home typically needs a 2.5-ton unit, while a 3,000 sq ft home might require a 5-ton unit. Smaller units (1.5–2.5 tons) cost $3,500–$5,000 installed; mid-size units (3–3.5 tons) cost $4,500–$6,000; larger units (4–5 tons) cost $5,500–$7,500 or more.
Efficiency Ratings and Energy Costs
Air conditioner efficiency is measured by SEER2 rating. The minimum legal efficiency for new AC units in 2026 is 14 SEER2 in northern states and 15 SEER2 in southern states. A basic 14–16 SEER2 unit costs $3,500–$5,000 installed; mid-efficiency 16–18 SEER2 costs $4,500–$6,000; high-efficiency 18–22 SEER2 costs $5,500–$8,000. High-efficiency units can reduce cooling costs by 20–40% compared to minimum-efficiency models.
Installation Factors That Affect Cost
If your existing ductwork is damaged or undersized, you may need repairs or modifications costing $500–$2,000. If your electrical panel doesn't have sufficient capacity for the new AC unit, you may need an electrical upgrade costing $500–$1,500. Rooftop or second-story installations require additional labor, adding $500–$1,500 to the total cost.
Tax Credits and Rebates
In 2026, qualifying central air conditioners (SEER2 16+) are eligible for federal tax credits up to $600. Many utility companies also offer rebates of $300–$1,000 for high-efficiency AC installations. These incentives can meaningfully reduce your out-of-pocket cost.