Last August I crawled into an attic that hit 130 degrees to swap out a 14-year-old central air handler. The homeowner had been quoted three wildly different prices, from $5,800 to $11,200, for what looked like the same job. The spread wasn't a scam. It came down to ductwork, the size of the unit, and a SEER number nobody had bothered to explain to her.
Cooling costs swing harder than almost any other home system because you're paying for two things at once: a machine and the labor to integrate it with your house. A window unit is a plug-in appliance. A central system is a small construction project with refrigerant lines, electrical work, and sometimes a crane.
I'll walk through what each type actually costs, what drives the number up, and the parts of the job you never see from the thermostat. Sizing matters more than most folks realize, so if you want the deep version, our HVAC sizing guide pairs well with this.
What "AC installation cost" actually covers
When a contractor hands you a number, it bundles the equipment, the labor crew, materials like refrigerant and line sets, the electrical hookup, the permit, and a startup test. People assume they're paying for a box. They're paying for a system that has to be sealed, charged, and balanced.
Here's an example. A mid-range central AC quote of $7,500 might break down as roughly $3,200 for the condenser and coil, $2,800 for labor, $800 for materials and a new line set, $450 for the permit and inspection, and $250 for disposal of the old unit. The equipment is often less than half the bill.
"The expensive quote means the contractor is gouging me." Not always. A higher number frequently includes a properly sized load calculation, a new electrical disconnect, and sealed ductwork. The cheap quote sometimes skips these and you pay later in energy bills or a short equipment life.
Central air conditioning by home size
Central AC is priced by tonnage, which is just how much heat the system can move per hour. One ton handles roughly 400 to 600 square feet depending on insulation, ceiling height, and climate. Bigger isn't better. An oversized unit short-cycles, leaving your house clammy and your compressor worn out early.
These ranges assume usable existing ductwork. If ducts need replacing, add $2,000 to $6,000.
| Home size | System capacity | Typical installed cost |
|---|---|---|
| Up to 1,200 sq ft | 2 ton | $4,500 - $7,500 |
| 1,200 - 1,800 sq ft | 2.5 - 3 ton | $5,500 - $9,000 |
| 1,800 - 2,500 sq ft | 3.5 - 4 ton | $7,000 - $11,500 |
| 2,500 - 3,500 sq ft | 4 - 5 ton | $9,000 - $14,500 |
One thing I always check before quoting: the electrical panel. An older 100-amp panel sometimes can't handle a new condenser plus everything else, and a panel upgrade can tack on $1,500 to $3,000 nobody planned for.
What SEER and SEER2 do to the price
SEER stands for Seasonal Energy Efficiency Ratio. A higher number means the unit produces more cooling per watt. As of 2023 the industry shifted to SEER2, a stricter test that runs about 4 to 5 percent lower than the old SEER for the same equipment, so don't panic when the sticker looks smaller.
The minimum legal efficiency now sits at 14 to 15 SEER2 depending on your region. Premium variable-speed systems reach 20 SEER2 and beyond.
- Baseline (14 - 15 SEER2): lowest upfront cost, fine for mild climates or rentals.
- Mid-tier (16 - 18 SEER2): roughly $1,000 - $2,500 more, noticeably lower summer bills.
- High-efficiency (19+ SEER2): $3,000 - $6,000 premium, best for hot climates and long ownership.
Don't chase the highest SEER2 number if you live somewhere with short, mild summers. The energy savings won't pay back the premium before the unit ages out. In Phoenix it's a no-brainer. In Seattle, I usually steer people to mid-tier.
Ductless mini-split systems
A mini-split skips ductwork entirely. An outdoor compressor feeds one or more wall-mounted indoor heads through a small refrigerant line, so the only hole in your wall is about three inches wide. They're my go-to for additions, garages, and old houses with no ducts to work with.
Single zone versus multi-zone
A single-zone mini-split cooling one room typically runs $3,000 to $6,000 installed. Multi-zone systems, where one outdoor unit feeds several indoor heads, scale up fast.
| Configuration | Coverage | Installed cost |
|---|---|---|
| Single zone | 1 room | $3,000 - $6,000 |
| Two zone | 2 rooms | $5,500 - $9,500 |
| Three to four zone | Most of a small home | $8,000 - $16,000 |
The labor is cleaner than central air but still skilled work. The line set has to be vacuumed and charged correctly, and a sloppy mounting bracket on an exterior wall can cause vibration cracks over time. If you ever spot hairline cracks spreading from a wall penetration, our crack severity guide helps you judge whether it's cosmetic or structural.
Window and portable units
Window AC is the budget tier and it's an appliance, not an installation. A basic 5,000 BTU unit for a bedroom runs $150 to $300. A larger 12,000 to 15,000 BTU unit for a living room lands around $400 to $700.
Portable units cost a bit more for the same cooling power and are less efficient, usually $350 to $800, but they don't need a window that opens the right way. Neither requires a permit or a contractor, which is the whole appeal.
A large window or portable unit can pull 12 to 15 amps. Run it on a dedicated circuit if you can. I've seen people trip a breaker every afternoon because the AC shares a line with a microwave and a space heater.
What pushes your final number up or down
Two identical houses on the same street can get quotes $4,000 apart. Here's what moves the needle.
- Ductwork condition: leaky or undersized ducts add thousands and hurt efficiency.
- Refrigerant type: systems using the newer R-454B refrigerant cost a little more right now as supply settles.
- Accessibility: a condenser that needs a crane to reach a rooftop or a tight side yard adds labor.
- Electrical: new disconnect, whip, or a panel upgrade.
- Season: mid-summer emergency installs cost more than a planned spring swap.
Cooling is also tangled up with your other big mechanical systems. If you're already opening walls or budgeting a full mechanical refresh, it's worth looking at your hot water setup too. Our breakdown of a water heater tank vs tankless decision uses the same payback logic you'll apply to SEER2.
Window units: $150 - $800, DIY. Mini-splits: $3,000 - $16,000 by zone count. Central air: $4,500 - $14,500 by tonnage, plus ductwork if needed. SEER2 efficiency and electrical work are the two biggest swing factors.
FAQ
Is it cheaper to repair my old AC or replace it?
A good rule is the "$5,000 test": multiply the repair cost by the unit's age in years. If it tops $5,000 or the system uses discontinued R-22 refrigerant, replacement usually wins. A 12-year-old unit needing a $600 compressor part is rarely worth saving.
Do I really need a permit for AC installation?
For central and mini-split systems, yes, in nearly every US jurisdiction. The permit and inspection (roughly $250 to $600) confirm the electrical and refrigerant work meet code. Skipping it can void warranties and snag a future home sale. Window units need no permit.
Can I install a mini-split myself?
DIY kits exist with pre-charged lines, and a handy homeowner can manage a single zone. The catch is that handling refrigerant for anything beyond pre-charged kits requires EPA certification, and a bad vacuum or charge will shorten the unit's life. For multi-zone work, hire a licensed tech.
If you take one thing from all this, let it be sizing. I've replaced more units killed by being too big than too small. Get a real load calculation, ask your contractor to explain the SEER2 number and the electrical scope in plain English, and don't let a single low bid talk you out of the permit. A cooling system installed right disappears into the background for fifteen years, which is exactly what you want.
