Everything you need to know before, during, and after a new AC installation. Written for homeowners who want to make informed decisions and avoid common costly mistakes.
Replacing an AC system is one of the largest home expenses — typically $5,000-$15,000+ in South Florida. Yet most homeowners go into it blind, relying entirely on the contractor's recommendations without knowing what questions to ask.
This checklist covers the entire process from evaluating whether you actually need a replacement through post-installation verification. Print it, check off items, and use it to hold your contractor accountable.
- Do You Actually Need a Replacement?
- Pre-Installation Checklist
- Contractor Evaluation
- Equipment Selection
- Installation Day
- Post-Installation Verification
- Common Mistakes to Avoid
- Florida-Specific Requirements
Before spending $5,000-15,000+, verify the problem actually requires a new system.
- System is 15+ years old AND has a major component failure (compressor, coil)
- Repair cost exceeds 50% of replacement cost
- System uses R-22 refrigerant (phased out, costs $100-300/lb to recharge)
- Multiple breakdowns in the past 2 years
- Energy bills have steadily increased despite maintenance
- Home comfort is consistently poor (hot/cold spots, humidity problems)
- System is undersized or oversized for your home
- System is under 10 years old with first major issue
- Problem is a single component (capacitor, contactor, fan motor)
- Repair cost is under $1,000 on a system less than 12 years old
- Refrigerant leak on newer R-410A system (can be found and fixed)
- Thermostat or control board issue
If repair cost > 50% × replacement cost, replace. If your system is over 12 years old, lower that threshold to 30% since more failures are likely coming.
Example: Compressor replacement quote is $2,500 on a 13-year-old system. New system costs $8,000. $2,500 > 30% of $8,000 ($2,400) → Replace.
- Know your current system: Write down brand, model number, tonnage, SEER rating (on the outdoor unit nameplate)
- Check your ductwork age: If ducts are 20+ years old, factor duct replacement into your budget
- Review your electric panel: A high-efficiency system may need different breaker sizing
- Check insulation: Poor insulation means you'll need a larger system regardless of brand
- Measure your home: Know the approximate square footage, number of rooms, ceiling height, and window count/orientation
- Document comfort problems: Which rooms are too hot? Too cold? Humid? This helps the contractor design the right solution
- Pull your permit history: Your county building department website shows what permits exist for your HVAC system
Always get at least 3 quotes. Here's how to make them comparable:
- Request a Manual J load calculation from each contractor (not just "1 ton per 400 sq ft" rules of thumb)
- Ask each contractor to quote the same tonnage and SEER rating so you can compare labor and installation quality
- Get quotes that itemize: equipment, labor, materials, permit, startup, and warranty costs
- Verify each quote includes permit pulling AND final inspection
- Ask about ductwork: will they inspect/repair/modify existing ducts?
| Red Flag | Why It's a Problem |
|---|---|
| No Manual J calculation | Guessing at system size leads to oversizing (humidity) or undersizing (poor cooling) |
| "We don't pull permits" | Illegal in Florida. Voids manufacturer warranty. Fails home inspection if you sell. |
| Drastically lower than other quotes | Cutting corners on installation quality, wrong equipment, or no permit |
| Pressure to decide today | Legitimate contractors give you time to compare |
| Won't provide contractor license number | May not be licensed — verify at myfloridalicense.com |
- Active Florida CAC license — Verify at myfloridalicense.com
- Registered with your county — Local business tax receipt / competency card
- Insurance: General liability + workers' compensation
- Manufacturer authorized dealer — For the brand being installed (ensures warranty support)
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"Will you perform a Manual J load calculation?" — The only correct way to size a system. Takes 30-60 minutes. If they say "we don't need to," walk away.
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"Who pulls the permit?" — The contractor must pull it. If they ask you to, that's a red flag.
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"Will there be a county inspection?" — Yes, always. The contractor schedules it after installation.
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"What brand and model number specifically?" — Get the exact model, not just "a Trane 3-ton." Model numbers determine features, efficiency, and warranty terms.
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"What's included in the warranty?" — Differentiate between manufacturer warranty (parts) and contractor warranty (labor). Get labor warranty in writing.
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"How will you handle the ductwork?" — Will they inspect, seal, or modify ducts to match the new system? Putting a new system on bad ductwork is like putting new tires on a car with broken axles.
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"What refrigerant does this system use?" — Should be R-410A or newer (R-32, R-454B). Never install a new R-22 system.
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"How long will installation take?" — Standard split system: 1 day. If ductwork is involved: 2-3 days. Anything quoted at "a few hours" for a full system is concerning.
- Look up contractor on myfloridalicense.com — verify active CAC license
- Check BBB, Google Reviews, and Yelp (10+ reviews minimum)
- Ask for 3 references from recent installations (past 90 days)
- Verify insurance — call the insurance company listed on their certificate
- Confirm they are a factory-authorized dealer for the brand they're quoting
SEER (Seasonal Energy Efficiency Ratio) measures cooling efficiency. Higher = more efficient = lower electric bills.
| SEER Rating | Classification | Typical Monthly Savings vs 10 SEER |
|---|---|---|
| 14 | Minimum (FL code) | ~28% |
| 16 | Mid-range | ~38% |
| 18 | High efficiency | ~44% |
| 20+ | Premium efficiency | ~50%+ |
Florida minimum: 15 SEER for split systems (as of 2023 federal standard). Don't let anyone install a 14 SEER system — it doesn't meet code.
| Type | Best For | Typical Cost (Installed) |
|---|---|---|
| Standard split (condenser + air handler) | Most homes with existing ductwork | $5,000-12,000 |
| Heat pump split | Homes wanting heating + cooling efficiency | $6,000-14,000 |
| Ductless mini-split | Room additions, homes without ducts | $3,000-8,000 per zone |
| Package unit | Homes where all equipment sits outside | $5,000-10,000 |
- Variable-speed compressor — Runs at lower speeds for longer, dramatically improving dehumidification. Worth the upgrade in Florida.
- Variable-speed air handler — Better airflow distribution, quieter operation, improved humidity control.
- High SEER rating (16+) — Your AC runs 8-10 months/year. Efficiency savings compound fast.
- Corrosion-resistant condenser coil — Salt air near the coast destroys standard coils in 5-7 years. Look for "coastal" or "Spine Fin" coil options.
- Smart thermostat compatibility — Remote monitoring and humidity control.
| Problem | Cause | Symptoms |
|---|---|---|
| Oversized | Manual J not done, "bigger is better" myth | Short cycling, high humidity, uneven cooling, higher bills |
| Undersized | Cost cutting, underestimated heat load | Runs constantly, can't reach set temp on hot days, high bills |
| Correctly sized | Proper Manual J calculation | Runs 15-20 min cycles, maintains temp and humidity, efficient |
The most common installation error in Florida is oversizing. An oversized unit costs more to buy, more to run, dehumidifies poorly, and wears out faster due to short cycling.
- Clear 3 feet around the outdoor unit location
- Clear path from the front door to the air handler location
- Remove items from around the air handler (closet, utility room, attic access)
- Protect flooring — ask the crew if they bring drop cloths
- Confirm someone 18+ will be home all day
- Confirm the permit has been pulled (ask for the permit number)
- Old refrigerant is recovered (not vented — that's an EPA violation)
- New line set is being installed (not reusing old copper lines if switching refrigerant types)
- Condensate drain has a proper P-trap and drains to an appropriate location
- Ductwork connections are sealed with mastic or metal tape (NOT cloth "duct tape")
- Air handler is level
- Outdoor unit is on a level pad with proper clearance (12"+ from walls, 24"+ between units)
- Electrical disconnect is installed near the outdoor unit
- Thermostat wiring is correct (especially if upgrading to smart thermostat)
- New filter is installed and you know the correct size
- System is charged per manufacturer specs (subcooling/superheat method, not "by feel")
- Contractor performs startup procedure and tests all modes (cool, heat if applicable, fan)
- Temperature drop across the coil is 15-22°F (measured at the return and closest supply)
- Condensate drains freely — pour water in the drain pan to verify
- No unusual noises from indoor or outdoor unit
- Thermostat operates correctly in all modes
- Contractor explains maintenance requirements
- You have all paperwork: invoice, permit number, warranty registration info, Manual J report
- Register your equipment warranty with the manufacturer (most require registration within 60-90 days for full warranty)
- Verify the county inspection was completed and passed
- Monitor energy bills — you should see improvement within the first full billing cycle
- Check that all rooms cool evenly
- Verify indoor humidity stays below 55%
- Listen for unusual noises during startup and operation
- Check the condensate drain weekly for the first month
| Task | Frequency | DIY or Pro |
|---|---|---|
| Change air filter | Monthly (1") or quarterly (4") | DIY |
| Clean condensate drain | Quarterly | DIY |
| Clean outdoor condenser coil | Bi-annually | DIY or Pro |
| Professional maintenance tune-up | Annually | Pro |
| Check refrigerant charge | Annually | Pro |
| Inspect ductwork | Every 2-3 years | Pro |
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Choosing the cheapest quote — Installation quality matters more than equipment brand. A poorly installed premium system will underperform a well-installed mid-range system.
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Skipping the Manual J — "One ton per 400 square feet" is a myth. Actual sizing depends on insulation, windows, orientation, ductwork, and occupancy.
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Not pulling permits — Florida requires permits for HVAC replacement. No permit = no inspection = no warranty = problem when you sell.
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Ignoring ductwork — New equipment on old, leaky ductwork wastes 20-30% of cooling capacity. At minimum, have ducts inspected and sealed.
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Oversizing "just in case" — Bigger is NOT better for AC. An oversized system costs more, dehumidifies poorly, and wears out faster.
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Not registering the warranty — Most manufacturers require online registration within 60-90 days. Miss it and your 10-year warranty becomes 5 years.
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Forgetting about the thermostat — A smart thermostat with humidity control can improve comfort and efficiency by 10-15%.
- Minimum 15 SEER for split systems
- Permit required for all HVAC replacements
- Licensed CAC contractor must perform the work
- County inspection required after installation
- Hurricane straps may be required for outdoor units in high-wind zones
Florida requires a CAC (Class A Air Conditioning) license for HVAC installation. Verify at myfloridalicense.com.
Hiring an unlicensed contractor is illegal under Florida Statute 489.127 and can result in fines for both the contractor and homeowner. More importantly, unlicensed work voids manufacturer warranties and won't pass inspection.
Check these before purchasing:
- FPL rebates — Florida Power & Light offers rebates for high-efficiency systems
- Federal tax credits — Energy-efficient heat pumps may qualify for 25C/25D credits
- Manufacturer promotions — Seasonal rebates from Trane, Carrier, Lennox, etc.
- PACE financing — Property Assessed Clean Energy programs available in many FL counties
If you're replacing your AC system in South Florida and want a second opinion on quotes, sizing, or equipment selection — a licensed HVAC contractor can provide an honest assessment.
Need help evaluating your options? AC Repair Today — Licensed Florida contractor (CAC1824118) serving Miami-Dade, Broward, and Palm Beach County. Same-day consultations available.
Found outdated information or want to add a tip? Open an issue or submit a pull request. This guide is community-maintained.
This project is licensed under the MIT License — see the LICENSE file for details.
Maintained by AC Repair Today — Helping South Florida homeowners make smart HVAC decisions.