Replacing an AC unit when you already have ductwork and electrical in place runs $3,000–$8,000 for most homes. That’s the condenser (outdoor unit) plus the air handler or evaporator coil (indoor unit), plus labor for a straight swap. If you’re starting from scratch in a home with no existing AC at all, that’s a different scope. See central air installation cost.
Run the numbers
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Before you approve a replacement
- 1Did you run a load calculation (Manual J) for my home, or are you sizing off the old unit?
- 2What SEER2 / AFUE / HSPF2 rating am I actually getting, and how does that compare to code minimum?
- 3Can I get this exact quote in writing to compare against at least one other bid?
- 4What’s included — permit, old-unit removal, new pad or disconnect, startup and commissioning?
- 5What’s the manufacturer’s warranty vs. the installer’s labor warranty, and do I need to register anything?
- 6What’s the total installed price, with any financing costs broken out separately?
Cost by system size and tier
| Unit size | Entry (single-stage) | Mid (two-stage) | Premium (variable-speed) |
|---|---|---|---|
| 1.5–2 ton | $2,500–$4,000 | $3,500–$5,500 | $5,000–$7,500 |
| 2.5–3 ton | $3,000–$5,500 | $4,500–$7,000 | $6,000–$9,500 |
| 3.5–5 ton | $4,000–$7,000 | $5,500–$8,500 | $7,500–$12,000+ |
Labor for a straight swap typically adds $1,000–$2,500 on top of equipment, depending on your market and job complexity. The ranges above include labor for a standard swap with no major scope additions.
Efficiency tier is the biggest lever inside these ranges: a single-stage entry unit keeps the number low; a variable-speed system with modulating compressor pushes well above it, and pays back in lower utility bills and better humidity control over 15-plus years.
📊 Deciding whether to repair or replace?
The cost data in this guide comes from real, itemized HVAC contractor bids analyzed with BidSmart, a bid-comparison tool from our team. Upload the quotes you’ve received and see how they compare line-by-line — scope, equipment tiers, and the items a low bid quietly leaves out — before you sign anything.
What “unit replacement” includes (and what triggers extra charges)
A standard unit replacement (existing infrastructure intact) covers:
- Removing and disposing of the old outdoor condenser and indoor coil
- Installing the matched replacement pair (condenser + coil)
- Connecting existing refrigerant line set, electrical, and condensate drain
- Commissioning: verifying refrigerant charge by measurement, checking airflow and temperature split
Common extras that add to the base price:
- Line set replacement: if the existing line set is undersized, corroded, or kinked, replacing it adds $500–$1,500 depending on length and routing
- Electrical work: if your panel needs a new or upgraded circuit for the new unit’s amperage draw, plan for $300–$800
- Pad and disconnect: a cracked concrete pad or corroded disconnect box are typically minor ($150–$300 combined) but appear on itemized bids
- Permits: required in most jurisdictions; typically $75–$250 and included in a reputable bid; confirm it’s there before signing
Ask every contractor to itemize these as separate line items. A bid that rolls everything into one number makes it impossible to compare scopes, and scope differences routinely account for more price spread than brand or equipment differences do.
The refrigerant transition: what it means for your replacement
New residential AC equipment as of January 1, 2025 ships with R-454B or R-32 refrigerant, not R-410A. Your existing R-410A system can still be serviced with reclaimed refrigerant, but new replacement equipment will not use R-410A.
This matters practically in one way: when you replace the outdoor unit, the indoor coil should also be replaced to ensure the matched system is certified for the new refrigerant type. Mixing an old R-410A coil with a new R-454B condenser creates a mismatched system that voids the manufacturer warranty and may not meet the published efficiency ratings.
A good bid replaces both. If a contractor quotes outdoor-unit-only on a system built before 2025, ask specifically whether the coil is being replaced and whether the matched system is AHRI-certified.
The repair-vs-replace decision
The standard field heuristic: if repair cost × unit age (in years) exceeds $5,000, get replacement bids. A $400 capacitor repair on a 10-year-old unit ($4,000 effective cost) argues for repair; a $1,800 compressor on the same unit ($18,000) argues strongly for replacement.
A 15-year-old unit is past its actuarial peak regardless of what it costs to fix today. The newer R-454B/R-32 systems are meaningfully more efficient and will carry a 10-year parts warranty from day one; that’s real money in utility bills and repair risk over the next decade.
For a more detailed cost-component breakdown and the repair-or-replace math, see AC repair cost by failure type and the full HVAC cost index.
Before you sign: three questions for every replacement bid
- “Is this an AHRI-matched system? Can I see the certificate?” Good answer: yes, with the certificate number. An unmatched pair voids your warranty and your efficiency ratings.
- “Does the quote include the permit, and is the line set being replaced or reused?” Both should be answered in writing, not verbally.
- “What labor warranty do you include on top of the 10-year parts warranty?” One year is standard; two or more is a sign the installer stands behind their work. A tech who cuts corners on installation doesn’t offer a long labor warranty.
For the full checklist of what to ask before signing any HVAC contract, see The HVAC Quote Checklist.
