How much does AC replacement cost in St. Louis?

The cost of central air conditioner replacements in the St. Louis area varies depending on the size of your home, the efficiency rating of the system you choose, and whether any ductwork modifications are needed. A standard single-stage system for a typical Kirkwood or Ballwin ranch home will come in on the lower end of the cost range. High-efficiency variable-speed systems for larger homes in Wildwood or Chesterfield run higher. We provide written, itemized estimates before any work starts, so you know exactly what you're paying for.

Can I get financing for AC replacement in St. Louis?

Yes. Aire Serv of St. Louis offers financing options for qualifying customers, subject to credit approval. Replacing an aging AC is a significant investment, and spreading that cost over time makes a high-efficiency system more accessible than paying for it all at once. Ask our team about available payment plans when you schedule your estimate.

How do I know if my AC needs repair or full replacement?

The 5,000 rule is a useful starting point: multiply the repair cost by the age of the system in years. If that number exceeds $5,000, replacement is usually the smarter financial call. A 12-year-old unit facing a $450 capacitor swap is an easy repair. That same 12-year-old unit with a failed compressor needing $1,800 in parts and labor is a much stronger case for replacement. The refrigerant type matters too. Systems running on R-22 are expensive to service because the refrigerant was phased out under EPA regulations, and recharging an R-22 system has become significantly more costly in recent years.

What other HVAC services does Aire Serv of St. Louis offer?

Beyond air conditioning replacement, our team handles furnace repair and replacement, heat pump installation, ductless mini-split systems, thermostat upgrades, whole-home humidifiers and dehumidifiers, air duct cleaning and repair, air filter installation, and UV lamp systems for indoor air quality. We also offer HVAC maintenance agreements that cover both your heating and cooling systems year-round. For homes across Mehlville, Sunset Hills, Crestwood, and Des Peres, we're the team St. Louis calls for complete heating and cooling service.

What is the difference between a heat pump and a central AC system for St. Louis homes?

A heat pump handles both cooling in summer and heating in winter by reversing the refrigerant cycle. Central AC handles cooling only and pairs with a gas furnace for heat. Heat pumps have become far more common in St. Louis suburbs like Eureka and Wildwood, where homeowners want to reduce gas dependence or qualify for federal energy-efficiency tax credits. Modern cold-climate heat pumps operate efficiently down to 0°F, which covers nearly every St. Louis winter scenario. The right choice depends on your current heating setup, energy costs, and how long you plan to stay in the home.

Should I replace my AC and furnace at the same time in St. Louis?

It's worth serious consideration if your furnace is within five years of your AC's age, because the two systems share the air handler and coil. Replacing them together saves on labor and lets us match the variable-speed blower in a new furnace to a variable-speed condenser, which improves efficiency and humidity control significantly. If your furnace is newer and in good shape, replacing only the AC often makes sense. We'll give you an honest recommendation either way, with no pressure to do more than your home actually needs.

How long does a new AC system last in St. Louis?

A properly sized and installed central air conditioner typically lasts 15 to 20 years in the St. Louis climate. The keyword is "properly sized." Oversized units are extremely common in older St. Louis neighborhoods, and they wear out faster because they are constantly short-cycling. Annual maintenance, clean air filters, and keeping the outdoor condenser clear of debris extend that lifespan. Our maintenance agreements include a seasonal cooling checkup that covers refrigerant levels, coil cleaning, electrical connections, and thermostat calibration.

What size AC unit does my St. Louis home need?

Sizing is done with a Manual J load calculation, which accounts for your home's square footage, insulation levels, window area, orientation, and local climate data. St. Louis sits in a mixed-humid climate zone, which means your system needs to handle both high summer sensible heat loads and significant latent (moisture) loads. A system sized only for square footage often misses the humidity piece entirely. We run full load calculations on every replacement job, not estimates based on the old unit's tonnage.

Who handles AC replacement near Chesterfield, Wildwood, and West St. Louis County?

Our team covers a wide service area across St. Louis and St. Louis County, including Chesterfield, Wildwood, Ballwin, Ellisville, Manchester, Fenton , Eureka , Ladue, Frontenac, Town and Country, Des Peres, Glendale, Kirkwood, Brentwood, Webster Groves, Maplewood, Oakville, Sunset Hills, Imperial, Barnhart, and Mehlville. Ready to move forward or want an honest second opinion on a repair quote? Contact the St. Louis HVAC team at Aire Serv to schedule your assessment.

What are the signs my AC needs replacement, not repair?

Your system is 12 to 15 years old or older and has needed multiple repairs in the past two seasons Repair costs are approaching 50% of what a new system would cost Your home never feels cool or comfortable, even when the unit runs constantly Energy bills have climbed noticeably without a change in usage habits The system uses R-22 refrigerant, which is no longer manufactured and costs significantly more to recharge

AC Replacement in St. Louis, MO

St. Louis summers are brutal. By July, heat indexes push past 100°F, and aging AC systems start showing their limits. If yours is short-cycling, blowing warm air, or piling up repair bills, it may be time to replace it. Aire Serv of St. Louis handles AC replacement across the metro, from Chesterfield and Wildwood to Kirkwood and Oakville, with upfront pricing before any work begins. Call a St. Louis HVAC specialist today.

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What the AC Replacement Process Looks Like

Replacing a central air conditioner involves more than swapping out the outdoor unit. Our process starts with a full assessment of your existing system: we check the age and condition of the air handler, test refrigerant charge, inspect the ductwork for leaks or restrictions, and evaluate whether your current equipment matches the load demands of your home.
St. Louis homes built in the 1970s and 1980s, in neighborhoods like Maplewood, Webster Groves, and Brentwood, often run oversized equipment that was never sized to current energy efficiency standards. An oversized unit short-cycles, meaning it cools quickly but shuts off before it can pull humidity out of the air. In a city where August air feels like a sauna, that's a real problem.
Once the assessment is done, our Home Comfort Designer will walk you through your options. We work with Ruud and American Standard, covering efficiency ratings from entry-level SEER2 systems up to high-efficiency variable-speed units. A 16 SEER2 system runs substantially quieter than the aging 10 or 12 SEER units common in older St. Louis homes. For Eureka and Gray Summit properties that rely on heat pumps, we handle sizing and replacement as part of the same workflow. On install day, we recover the old refrigerant properly, set the new system per manufacturer specifications, and run a full startup check and airflow test before we leave.

Why St. Louis Homeowners Choose Aire Serv for AC Replacement

We quote by the job, not by the hour. That means you know the full cost before we start, and it doesn't change when the install takes longer than expected or requires an extra set of hands. Every replacement comes backed by the Neighborly Done Right Promise®, so if something isn't right after we leave, we make it right. Our team includes licensed journeyman technicians and system designers with backgrounds from Ranken Technical College and State Technical College of Missouri, which means your new system gets sized and installed by people who trained specifically for this work.

St. Louis has its own set of HVAC challenges. The city's humidity swings sharply between seasons, and homes in areas like Ladue, Frontenac, and Town and Country often have complex multi-zone systems that require careful balancing during replacement. We factor all of that in. You get a cooling system matched to your home's actual load, not just a unit that fits where the old one was. Our 7-day-a-week customer support means you're never waiting until Monday to get a callback scheduled.

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Why St. Louis Homeowners Choose Aire Serv for AC Replacement

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HVAC Services in St Louis and Surrounding Areas

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Frequently Asked Questions About AC Replacement: St. Louis, MO

- Your system is 12 to 15 years old or older and has needed multiple repairs in the past two seasons
- Repair costs are approaching 50% of what a new system would cost
- Your home never feels cool or comfortable, even when the unit runs constantly
- Energy bills have climbed noticeably without a change in usage habits
- The system uses R-22 refrigerant, which is no longer manufactured and costs significantly more to recharge
The cost of central air conditioner replacements in the St. Louis area varies depending on the size of your home, the efficiency rating of the system you choose, and whether any ductwork modifications are needed. A standard single-stage system for a typical Kirkwood or Ballwin ranch home will come in on the lower end of the cost range. High-efficiency variable-speed systems for larger homes in Wildwood or Chesterfield run higher. We provide written, itemized estimates before any work starts, so you know exactly what you're paying for.
A properly sized and installed central air conditioner typically lasts 15 to 20 years in the St. Louis climate. The keyword is "properly sized." Oversized units are extremely common in older St. Louis neighborhoods, and they wear out faster because they are constantly short-cycling. Annual maintenance, clean air filters, and keeping the outdoor condenser clear of debris extend that lifespan. Our maintenance agreements include a seasonal cooling checkup that covers refrigerant levels, coil cleaning, electrical connections, and thermostat calibration.
Sizing is done with a Manual J load calculation, which accounts for your home's square footage, insulation levels, window area, orientation, and local climate data. St. Louis sits in a mixed-humid climate zone, which means your system needs to handle both high summer sensible heat loads and significant latent (moisture) loads. A system sized only for square footage often misses the humidity piece entirely. We run full load calculations on every replacement job, not estimates based on the old unit's tonnage.
It's worth serious consideration if your furnace is within five years of your AC's age, because the two systems share the air handler and coil. Replacing them together saves on labor and lets us match the variable-speed blower in a new furnace to a variable-speed condenser, which improves efficiency and humidity control significantly. If your furnace is newer and in good shape, replacing only the AC often makes sense. We'll give you an honest recommendation either way, with no pressure to do more than your home actually needs.
A heat pump handles both cooling in summer and heating in winter by reversing the refrigerant cycle. Central AC handles cooling only and pairs with a gas furnace for heat. Heat pumps have become far more common in St. Louis suburbs like Eureka and Wildwood, where homeowners want to reduce gas dependence or qualify for federal energy-efficiency tax credits. Modern cold-climate heat pumps operate efficiently down to 0°F, which covers nearly every St. Louis winter scenario. The right choice depends on your current heating setup, energy costs, and how long you plan to stay in the home.
Beyond air conditioning replacement, our team handles furnace repair and replacement, heat pump installation, ductless mini-split systems, thermostat upgrades, whole-home humidifiers and dehumidifiers, air duct cleaning and repair, air filter installation, and UV lamp systems for indoor air quality. We also offer HVAC maintenance agreements that cover both your heating and cooling systems year-round. For homes across Mehlville, Sunset Hills, Crestwood, and Des Peres, we're the team St. Louis calls for complete heating and cooling service.
The 5,000 rule is a useful starting point: multiply the repair cost by the age of the system in years. If that number exceeds $5,000, replacement is usually the smarter financial call. A 12-year-old unit facing a $450 capacitor swap is an easy repair. That same 12-year-old unit with a failed compressor needing $1,800 in parts and labor is a much stronger case for replacement. The refrigerant type matters too. Systems running on R-22 are expensive to service because the refrigerant was phased out under EPA regulations, and recharging an R-22 system has become significantly more costly in recent years.
Yes. Aire Serv of St. Louis offers financing options for qualifying customers, subject to credit approval. Replacing an aging AC is a significant investment, and spreading that cost over time makes a high-efficiency system more accessible than paying for it all at once. Ask our team about available payment plans when you schedule your estimate.
Our team covers a wide service area across St. Louis and St. Louis County, including Chesterfield, Wildwood, Ballwin, Ellisville, Manchester, Fenton, Eureka, Ladue, Frontenac, Town and Country, Des Peres, Glendale, Kirkwood, Brentwood, Webster Groves, Maplewood, Oakville, Sunset Hills, Imperial, Barnhart, and Mehlville. Ready to move forward or want an honest second opinion on a repair quote? Contact the St. Louis HVAC team at Aire Serv to schedule your assessment.

Residential
Commercial

AC Replacement in St. Louis, MO

Schedule Online

What the AC Replacement Process Looks Like

Why St. Louis Homeowners Choose Aire Serv for AC Replacement

The Aire Serv Advantage

Aire Serv of St Louis

HVAC Services in St Louis and Surrounding Areas

Frequently Asked Questions About AC Replacement: St. Louis, MO

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