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Avatar for Fresh Air Heating & Cooling
Fresh Air Heating & Cooling
4.8(
277
)

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

8 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(
273
)

Serving O Fallon, MO and surrounding areas

Approved

In business since 2003

Free estimates

Emergency services offered

"Excellent! I love JT Dunn Heating and Cooling. We selected them out of 5 different contractors to install our brand new furnace and conditioner in 2017 and we hadn't had a problem since. We just had a 3 year tune-up and nothing was wrong and the ac is quietly humming away outside. Thanks to employee Robert Fitzgerald for coming out today and doing a awesome job and keeping us as customers!"
Additional Photos
Response time2 days
20 neighbors recently requested a quote
Recommended by90%of homeowners
Avatar for Hosack Plumbing Heating & Cooling
Hosack Plumbing Heating & Cooling
4.8(
344
)

Serving O Fallon, MO and surrounding areas

Approved

In business since 2009

Warranties offered

Credit card accepted

"Mike was awesome, very knowledgeable and friendly. Efficiently got the furnace running as it should be! Even took the time to educate me on what the issue was and explained what he did to fix it. Highly recommend!"
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+2

Response time6 days
10 neighbors recently requested a quote
Recommended by93%of homeowners
Avatar for Aire Serv of St. Louis
Aire Serv of St. Louis
5.0(
5
)

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!

Logo
23 neighbors recently requested a quote
Avatar for Wise Men Heating and Cooling, LLC
Wise Men Heating and Cooling, LLC
5.0(
7
)

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%
8 neighbors recently requested a quote
Avatar for Local Air Duct Pros
Local Air Duct Pros
4.5(
15
)

Serving O Fallon, MO and surrounding areas

Approved

Super Service Award Winner

In business since 2025

Free estimates

Credit card accepted

"Local Air Duct Pros did an outstanding job! The team was professional, punctual, and very thorough. I noticed a huge difference in air quality right away. Highly recommended!"
Response time7 hrs
Response rate97%
29 neighbors recently requested a quote
Avatar for Schraer Heating and Air Conditioning
Schraer Heating and Air Conditioning
5.0(
8
)

Serving O Fallon, MO and surrounding areas

Approved

In business since 1946

Free estimates

Emergency services offered

"I cannot say enough wonderful things about this amazing company! My daughter and I had been without a furnace for over 6 years. We used space heaters in the bedrooms, bathroom and kitchen, but the rest of the house stayed cold. Along with that, I had a constant fear of an electrical fire resulting from the units, because last year a young mother and her baby died in a house fire down the street from us, most likely caused from a space heater. When Schraer came to our home that offered to install gas furnace free off charge that was just sitting in their shop! We are truly Blessed and Grateful for their kindness and generosity! There are good people out there in the world, and the owners and employees of Schraer Heating and Cooling are some of best!"
Airlift rooftop unit
Duct installation
Geothermal job
Crane lift a rooftop unit
Finalize duct on a new construction

+3

Response time1 day
29 neighbors recently requested a quote
Avatar for AAA Home Services
AAA Home Services
4.9(
9
)

Serving O Fallon, MO and surrounding areas

Approved

In business since 1970

Warranties offered

Small jobs welcome

"I highly recommend AAA home services. They installed a brand new HVAC system and the entire process was trouble free every step of the way. I have had them out to service the system twice a year and the scheduling to do so is easy and the service has been excellent. AAA home services has always communicated well and I have had them do exceptional plumbing work including the installation of a hot water heater. Thank you AAA home services."
AC units from American Standard
HVAC Installation
HVAC Installation
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Showing 1-10 of 238
Air Conditioning questions, answered by experts

No, not all HVAC systems have a fresh air intake, but there are many advantages to having one. For example, a fresh air intake can boost the air quality inside your home and help your furnace run more effectively. Plus, it can make your house more energy efficient, possibly saving you money on your utility costs.

A new air conditioner capacitor will cost less than replacing the entire air conditioner system. While a capacitor itself will cost between $8 and $25, paying a professional to replace an AC capacitor will cost $180 on average. It’s not safe to replace an air conditioner capacitor on your own. 

Many factors affect how much adding air conditioning will cost you, from the size of your home to the size, type, brand, and installation specifics of the system itself. Chances are, a new central air conditioning system for a 2,000-square-foot house will cost somewhere between $3,900 and $7,900 to install, with an average around $6,000

For the most part, you should leave your AC fan in “auto” mode so that it only runs during a heating or cooling cycle. Keeping it in this position uses less energy, which equals lower utility bills. However, there are some situations where it’s better to leave your AC fan on, including if you have allergies or there are lots of people in your home.

You can buy a house with a 15-year-old HVAC system if you inspect the system for performance and budget for a replacement within the next three years. You can also negotiate the price with the sellers. Ask to look at the unit’s maintenance records and energy bills for the last two years to determine the shape of the HVAC system and its operating costs. Spend time in each room of the house to gauge if the HVAC keeps the home at a consistent temperature throughout.

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.