AC & Air Conditioner Cost: Complete Guide to Installation, Repair, and Replacement Pricing

Central air conditioning installation costs $6,000 on average, with most homeowners paying between $5,000 and $12,000. The type of system, its size, and your home's existing ductwork are the biggest factors behind where you land in that range.

When you request a quote through Serve Kei, a vetted local HVAC pro sizes your actual home and evaluates your existing ductwork, rather than pricing off a national average.

Cost by System Type

Central air is the most common choice for whole-home cooling and the figure most people mean by "AC installation cost." Portable and window units are far cheaper but only cool one room or zone.

Sizing: Tons and BTUs

Central AC is sized in tons, where one ton equals 12,000 BTUs of cooling per hour. Residential systems typically run 1.5 to 5 tons. As a rough starting point, homes need about 1 ton of cooling per 400 to 600 square feet, though insulation quality, climate, ceiling height, and window exposure all shift that number. A poorly insulated home in a hot climate needs more tonnage per square foot than a well-insulated one in a mild climate.

An undersized system runs constantly and never quite keeps the house cool. An oversized one cools too fast without properly removing humidity, and cycles on and off more than it should, both waste energy and add wear.

What Affects the Cost

Existing ductwork. A home with ductwork already in place for a furnace or previous central air system costs far less to convert than a home that needs ducts installed from scratch. Duct repairs or partial replacement add real cost when sections are damaged, undersized, or leaking.

SEER rating. Higher-efficiency units (higher SEER ratings) cost more upfront but lower monthly energy bills. This is a real trade-off between upfront cost and ongoing operating cost, not just a price tier.

System size (tonnage). Larger tonnage means more expensive equipment and, often, a bigger blower or air handler to match, which adds to installed cost.

Ductless vs. ducted. A ductless mini-split skips the ductwork question entirely, useful for additions, older homes without existing ducts, or cooling a single zone, but the per-zone equipment cost adds up for whole-home coverage.

Labor and permits. HVAC labor typically runs a meaningful share of the total, and most jurisdictions require a permit for a new or replaced central system.

Repair and Component Costs

Not every AC problem means a new system. Individual component repairs are usually far cheaper than replacement:

Refrigerant (Freon) cost. Price depends heavily on which refrigerant your system uses. A typical R-410A recharge runs $50 to $80 per pound installed. R-22, the older refrigerant, runs $90 to $150 per pound installed, roughly double, because it's no longer produced or imported in the US under federal phase-out rules. A central system needs about 2 to 4 pounds of refrigerant per ton of capacity, so a full recharge on an older R-22 system can add up fast. If your system still uses R-22 and needs a major recharge, that cost alone is often a strong argument for replacing rather than repairing.

Compressor replacement specifically tends to scale with tonnage, smaller 1.5 to 2 ton systems sit toward the lower end of that range, while 4 to 5 ton systems run toward the upper end.

Repair vs. Replace

Most central air systems last 15 to 20 years. As a rule of thumb, if your system's age in years multiplied by the repair cost estimate exceeds roughly $5,000, replacement is usually the more economical choice. Repair generally makes sense for a younger system with an isolated issue, a failed capacitor, a refrigerant leak, a bad fan motor. Replace when:

Getting an Accurate Quote

Have ready: your home's approximate square footage, whether you have existing ductwork, your current system's age if you're replacing one, and any rooms that run noticeably warmer or colder than the rest of the house.

Frequently Asked Questions

How much does central air cost to install?

$5,000 to $12,000, averaging around $6,000, for equipment and labor combined.

What size AC unit do I need?

Roughly 1 ton of cooling per 400 to 600 square feet of home, adjusted for insulation, climate, and sun exposure. A professional load calculation gives a precise number instead of a rule of thumb.

Is a ductless mini-split cheaper than central air?

For a single zone, often yes. For whole-home coverage, multiple mini-split zones can cost as much as or more than central air, especially in a home that already has usable ductwork.

How long does AC installation take?

A straightforward central air install with existing ductwork typically takes 1 to 2 days. New ductwork or electrical upgrades add time.

How long do central air systems last?

Typically 15 to 20 years with regular maintenance, filter changes, and annual tune-ups.

Why is my AC repair estimate so close to replacement cost?

Major components, compressors and coils especially, are expensive to replace individually. Once a repair estimate approaches half the cost of a new system, replacement usually makes more financial sense, particularly on an older unit.

How much does it cost to fix an AC unit?

Depends on what's wrong. A tune-up runs $75 to $200, a blower motor $300 to $900, a compressor $800 to $2,800, and an evaporator coil $600 to $2,700. Refrigerant recharges add $50 to $80 per pound for R-410A, or $90 to $150 per pound for the older, phased-out R-22.

Why does R-22 (Freon) cost so much more than newer refrigerant?

R-22 is no longer produced or imported in the US under federal phase-out rules, so supply is limited and shrinking. It typically costs roughly double R-410A per pound, and that gap will keep widening as remaining stock runs out.

Bottom Line

Most homeowners pay around $6,000 for central air installation, but system type, size, and existing ductwork can move that from under $1,000 for a portable unit to well over $10,000 for a ducted whole-home system. Get a proper load calculation rather than sizing by square footage alone, and compare quotes on the same system type and SEER rating.

Related reading

National averages are useful for planning. Verify pricing against a quote for your home before treating any range as final.