If your air conditioning unit isn’t functioning properly, you might need an AC recharge. Our guide will detail what a typical AC recharge cost in St Louis, MO looks like.
How Much Does AC Replacement Cost in St. Louis? [2026 Data]
Heating and air conditioning service costs depend on your project and location. Check with a local pro for your specific job.
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Highlights
The average St. Louis home is 1,700 square feet, which needs 3 tons of AC.
The minimum SEER requirement here is 14, but a higher SEER means lower cooling costs.
Permits cost around $79, plus inspection fees, for AC replacement projects in St. Louis.
Average summer temperatures in St. Louis reach the high 80s and low 90s.
AC replacement costs in St. Louis, Missouri, average $4,335, with costs commonly ranging from $2,689 for smaller units with lower efficiency ratings to over $6,386 for larger, more complex systems. St. Louis has humid summers with average temperatures in the high 80s to low 90s, so a working AC system is essential if you want to avoid feeling sticky and sweaty while relaxing at home.
AC Replacement Cost Factors
AC replacement costs in St. Louis depends on several different factors, from the square footage of the space you want to cool to the type of AC unit you want to the unit’s efficiency rating.
Home Size
The median home size in St. Louis, Missouri, is around 1,700 square feet, which needs 3 tons of AC. Here’s how much you can expect to spend on AC replacement in St. Louis based on the size of your home.
| Home Size (Square Feet) | Tonnage | AC Cost |
|---|---|---|
| 1,200 | 1.5–2 | $800–$2,000 |
| 1,500 | 2–3 | $2,000–$3,000 |
| 1,700 | 2.5–3 | $2,690–$6,390 |
| 2,000 | 3–4 | $4,340–$8500 |
| 2,200 | 3.5–4.5 | $4,500–9,000 |
| 2,500 | 4–5 | $4,750–$9,500 |
| 3,000 | 5+ | $5,000–$9,500 |
AC Unit Size
Your home needs the right AC unit size to cool your home efficiently. You should consult with an HVAC pro in St. Louis, Missouri, to find the appropriate AC size for your home, but you can estimate your costs with the guide below. Each 400 to 500 square feet of space needs about one ton, or 12,000 British Thermal Units (BTUs) of AC.
| Tonnage | BTUs | AC Cost |
|---|---|---|
| 1.5 | 18,000 | $800–$2,850 |
| 2 | 24,000 | $3,800–$4,260 |
| 3 | 36,000 | $4,340–$6,390 |
| 4 | 48,000 | $4,670–$7,950 |
| 5 | 60,000 | $5,000–$9,500 |
Type of AC
AC replacement costs in St. Louis depend on the type of AC you’re replacing. If you replace a central AC system that has existing ductwork with another central AC system, you’ll save on the costs to install new ductwork. However, the cost increases if you switch from ductless options to something with ductwork.
| Type of AC | Average Cost | Pros | Cons |
|---|---|---|---|
| Central | $2,689–$6,386 | Whole-house cooling | Difficult to install |
| Window | $60–$400 | Low cost | Limited cooling capacity |
| Portable | $80–$700 | Moves from room to room | Takes up floor space |
| Ductless | $3,000–$10,000 | No need to install ducts | Cools smaller areas only |
| Geothermal | $18,000–$45,000 | Energy-efficient | High installation cost |
Efficiency (SEER)
The higher the Seasonal Energy Efficiency Ratio, or SEER, of your AC system, the more efficient it will be. This can mean a higher up-front cost for higher SEER units, but that also translates to lower energy bills month after month. The minimum SEER requirement for St. Louis is 14.
| SEER | AC Cost |
|---|---|
| 14–15 | $800–$4,300 |
| 16–17 | $1,300–$5,800 |
| 18–19 | $2,000–$6,400 |
| 20+ | $3,500–$9,500 |
HVAC Pro Costs
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You may be able to replace a window or portable unit yourself, but if you’re replacing central AC, a ductless system, or another large AC system, you’ll need to secure permits and have the work completed by a licensed, certified pro.
Labor
To replace an AC system, you’ll pay $1,500 to $3,500 in labor costs in low- or medium-cost-of-living areas, including St. Louis. In total, labor makes up 30% to 50% of the total cost to replace your AC.
Permits
St. Louis requires AC replacement to be handled by a city-licensed mechanical contractor as well as a mechanical permit. The county of St. Louis requires a permit, which costs $79 per unit plus additional fees for inspections. Fortunately, your mechanical contractor will be able to schedule inspections and apply for proper permits and can conveniently add permit costs into the project total.
Additional Pros to Consider Hiring
If you’re installing a completely different type of AC system than your previous unit, you may want to consider hiring the following experts:
Electrician: An electrician can upgrade your electrical panel to properly support an updated AC system, especially if you go from a smaller AC unit to a larger one. Hiring an electrician in St. Louis, Missouri, costs $148 to $466.
Plumber: Expanding from a window unit to central AC? Make sure you have the proper drainage for a bigger system by hiring a plumber. Hiring a plumber in St. Louis, Missouri, costs $169 to $420.
Does AC Replacement Increase Home Value?
St. Louis summers bring high temperatures and humidity, so a newer AC system is an attractive feature for any home. AC replacement can increase home value in St. Louis by up to 10% and has a 30% or higher ROI.
How Angi Gets Its Cost Data
Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We survey real Angi customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.
Want to help us improve our cost data? Send us a recent project quote to [email protected]. Quotes and personal information will not be shared publicly.
Heating and air conditioning services reviews from real Angi homeowners in Saint Louis, MO
4.6★ avg. • 816 total reviews
- Lajuan J.
Generational TradesMan helped me fixed my condensing unit and furnace!! The prices were fair, and the team was very knowledgeable and respectful to my things
Generational Tradesman LLC - J L.
Got the job done right and saved us from a possible major heating/cooling issue before it got bad, so grateful for the kind professionals handling our problem so efficiently and properly!
Citi-Link Heating and Cooling - Jim Y.
I recently had a positive experience with Dunn Service regarding boiler issues, and I wanted to share my thoughts. The technician arrived promptly at the scheduled time and approached their tasks with expertise and precision, ensuring that all problems were thoroughly addressed. The pricing...
Dunn Heating Air Conditioning and Plumbing - Taylor M.
Daren was amazing! Iâ ve hired other companies to do work on my heating & cooling systems and they charge an arm and a leg to just show up. Finley was reasonable priced and was able to get up system up and running way faster than the big companies I hired previously! If you live in a condo...
- Mike K.
Terrible, heating and cooling system never fully functioned.
- Jessica G.
I didn't end up using Vasill, but wanted to leave a review anyway, because even though I went with another company, it was a very tough decision. Henry was very thorough, responsive, and friendly. He submitted a reasonable bid which came to me within a day or two. If anything falls through...
- Stanley V.
Service check and routine maintenance air-conditioning. This went great. Ryan explained what he was doing, was punctual and professional.
Air Comfort Service Inc - Siobhan S.
The company delayed their work 4 months (from December to March); asked us to move air conditioning units to accommodate their work, which we did; took our ~$10,000 deposit, and then closed. They did not do the work or return our ~$10,000 deposit.
The Foundation Doctor - Aj A.
Highly recommend this company! They were affordable, friendly, and quick cleaning all our air vents, registers, and dryer vent. They even offered recommendations to help us maintain the cleanliness and avoid future repairs / mold issues. Would absolutely recommend them to friends and hire...
Midwest Carpet and Duct Cleaning - Hanan M.
Great customer service and an expert in air conditioning installation. They were very professional.
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