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Avatar for Fresh Air Heating & Cooling
Fresh Air Heating & Cooling
4.8(
277
)
Central A/C - InstallCentral A/C - Service or RepairCentral A/C - Install - For Business+3 more

Serving O Fallon, MO and surrounding areas

Approved

In business since 1947

Free estimates

Emergency services offered

"Great Experience. I was concerned about the 22 yr age of our air conditioner able to keep working and wonder if a long wait time to get a product shipped like refrigerators last year, I called for a quote and within a week it was installed and working! Installers worked tirelessly until their work was done, clean and neat!"
Fresh Air Van
Additional Photos
Additional Photos
Additional Photos
Additional Photos

+2

11 neighbors recently requested a quote
Recommended by92%of homeowners
Avatar for Dunn Heating Air Conditioning and Plumbing
Dunn Heating Air Conditioning and Plumbing
4.7(
274
)
Central A/C - InstallCentral A/C - Service or RepairDuctless Mini-split A/C - Install or Replace

Serving O Fallon, MO and surrounding areas

Approved

In business since 2003

Free estimates

Emergency services offered

"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 for their professional services was reasonable. Overall, based on my experience with Dunn Service—characterized by politeness, professionalism, and fair pricing—I would highly recommend their services to anyone facing heating and air conditioning issues."
Additional Photos
Response time2 days
22 neighbors recently requested a quote
Recommended by89%of homeowners
Avatar for Hively Home Comfort LLC
Hively Home Comfort LLC
4.8(
47
)
Central A/C - Service or Repair

Serving O Fallon, MO and surrounding areas

Approved

In business since 2017

Free estimates

Credit card accepted

We take great pride in our experience, expertise, quality, and customer service that we provide to meet the consumer's needs. It is our mission to provide excellent workmanship and complete customer satisfaction from start to completion of a project. In order to understand the needs and expectations of our customers, we take great care to work and communicate with every customer in a professional manner. Our reputation is based on service, safety, and quality, regardless of how large or small the job.

3 neighbors recently requested a quote
Recommended by65%of homeowners
Avatar for All American Appliance Service Inc
All American Appliance Service Inc
4.5(
531
)
Central A/C - Service or RepairCentral A/C - Service or Repair - For Business

Serving O Fallon, MO and surrounding areas

Approved

In business since 1980

Free estimates

Emergency services offered

"The repairman came out on time and found the issue immediately. While he was capable of repairing my compressor, he recommended that I contact the manufacturer to take advantage of a warranty repair. His honesty and details for how to quickly engage the warranty service caught me by surprise, and I will not hesitate to call this company anytime I have an issue. I recommend this company."
Additional Photos
Response time2 days
4 neighbors recently requested a quote
Recommended by89%of homeowners
Avatar for Aire Serv of St. Louis
Aire Serv of St. Louis
5.0(
5
)
Central A/C - InstallAir Ducts & Vents - CleanCentral A/C - Service or Repair+1 more

Serving O Fallon, MO and surrounding areas

Approved

In business since 2024

Free estimates

Emergency services offered

Looking for reliable HVAC service in St. Louis? Aire Serv of St. Louis is your local expert for residential and commercial heating and cooling. From emergency AC repair during humid Missouri summers to furnace maintenance before the winter chill, our professional technicians are available to keep your home comfortable. We pride ourselves on transparent, upfront pricing, no overtime charges, and the "Done Right Promise." Whether you need a system replacement, duct cleaning, or a routine tune-up in Fenton, Webster Groves, or Kirkwood, we are the team you can trust. Breathe easy with Aire Serv—your comfort is our top priority. Call us today to schedule your service!

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26 neighbors recently requested a quote
Avatar for Wise Men Heating and Cooling, LLC
Wise Men Heating and Cooling, LLC
5.0(
7
)
Central A/C - InstallCentral A/C - Install - For BusinessCentral A/C - Service or Repair+2 more

Serving O Fallon, MO and surrounding areas

Approved

In business since 2000

Free estimates

Emergency services offered

"The father and son duo was very professional. My emergency happened after typical business hours but they still came out take a look at my thermostat. Very polite and informative. Once the store opened, they got what they needed and returned the next morning. They did an excellent job and are very affordable. I look forward to continuing business with them."
Full furnace
Full furnace
Full furnace
Heating Cooling HVAC
HVAC

+2

Response time7 hrs
Response rate100%
4 neighbors recently requested a quote
Avatar for Schraer Heating and Air Conditioning
Schraer Heating and Air Conditioning
5.0(
8
)
Central A/C - InstallCentral A/C - Service or RepairDuctless Mini-split A/C - Install or Replace+3 more

Serving O Fallon, MO and surrounding areas

Approved

In business since 1946

Free estimates

Emergency services offered

"The 3 Mustache Pledge! Schraer Heating and Cooling deserves every bit of praise I can give! I called them about a worrisome noise coming from my system — one that I could only describe through a few rather vague and comical sound effects. Despite my less-than-technical explanation, their technician quickly understood exactly what I meant, found the issue, and had it fixed in no time. Their professionalism, responsiveness, and ability to solve the problem so efficiently (and with good humor!) made the whole experience stress-free. I’m so grateful for their excellent service and expertise. Highly recommend Schraer Heating and Cooling to anyone looking for honest, skilled, and friendly professionals! I will definitely keep my maintenance agreement in full force and effect!"
Airlift rooftop unit
Duct installation
Geothermal job
Crane lift a rooftop unit
Finalize duct on a new construction

+3

Response time1 day
53 neighbors recently requested a quote
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Air Conditioning questions, answered by experts

You may be able to clean mold from your air conditioner in some cases. If the mold growth only takes up a small area, you can use either vinegar or bleach mixed with water to remove it. Larger areas of mold should be left to the professionals, though. It's also a good idea to leave mold removal to the pros if you are sensitive to mold or have asthma. 

Aside from needing HVAC repair, there are times when you may need to replace your unit. HVAC replacement costs $5,000 to $12,500. Here are some telltale signs that your HVAC unit is going bad:

  • Your unit is 10 years or older.

  • Your home is very humid.

  • The unit keeps cycling without producing cool air.

  • You need to repair the unit frequently.

Replacing an HVAC system does not always include new ductwork. The decision depends on the condition of your existing ducts. If they are in good shape, correctly sized for the new unit, and meet current standards, they can often be reused. However, if the ducts are damaged, poorly designed, or improperly sized, they will likely need to be replaced or upgraded to ensure the new system operates efficiently. An HVAC contractor will assess your ductwork and recommend the best course of action. Typically, ductwork is purchased separately, and a full replacement will add to the overall project cost.

A dual evaporator coil is a specific design that allows the AC system to cool different compartments at different levels. It’s usually seen in refrigerators and similar appliances, but not in whole-house air conditioning systems. Talk with your AC technician about the best uses for a dual evaporator coil.

The American Society of Heating, Refrigerating, and Air-Conditioning Engineers, or ASHRAE, sets the standard guidelines for air changes per hour in homes and businesses. The International Residential Code, or IRC, also sets ACH requirements for residences and bases those requirements off of ASHRAE standards plus climate specifics related to your location.

The O Fallon, MO homeowners’ guide to air conditioning services

From average costs to expert advice, get all the answers you need to get your job done.