We're Not
Comfortable
Until You Are
The weather is always comfortable inside your home, thanks to Design-Air Heating & Air Conditioning.
Get Certified HVAC Furnace & Air Conditioning Repair in Decatur Illinois
Design-Air Heating & Air Conditioning is a family-owned and operated HVAC company dedicated to customer satisfaction. Since 1977, we have been repairing, replacing, and maintaining HVAC systems of all makes and models for homes and businesses in Decatur, IL. We are a proud Carrier Factory Authorized Dealer and employ NATE-certified technicians, so you know we have the seal of approval from the best in the industry. If you suspect your AC or furnace is in disrepair, give Design-Air Heating & Air Conditioning a call. We offer after-hours services because we know system breakdowns don’t happen during convenient business hours.

About Us
We've Been the #1 Choice for HVAC Since 1977 in Decatur IL
Design-Air Heating & Air Conditioning is a family-owned and operated company since it was founded by John Hall in 1977. Currently operated by owner Josh Mower, our business continues to grow and thrive. Mower was born and raised in Decatur, IL, and has worked at Design-Air since 2000, providing 20+ years of service as a loyal, dependable employee. He chose to purchase the business from his long-time mentor, John Hall. Our new owner is focused on customer satisfaction and advances in HVAC technology. As the largest downstate geothermal dealer, you can trust our combined experience of 300+ years. Our team serves both residential and commercial customers with sales, service, and installation for air conditioning units and furnaces that are ideal for your home or business. Turn to the experts at Design-Air when you need a system replaced or routine service on your HVAC unit, and we’ll provide you with the comfort you deserve.

Trust Our HVAC Systems for Your Commercial Needs
No matter the season, our dependable HVAC systems will deliver the necessary heating and cooling to keep your business comfortable and functional.


Why Choose Design-Air Heating & Air Conditioning?
Design-Air Heating & Air Conditioning has been the leading HVAC expert for over four decades. Since then, we have provided long-lasting repair, replacement, and maintenance services to homes and businesses throughout Decatur, IL. Here are just a few reasons our customers continue to choose us for their air conditioning & furnace services.
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Free Estimates on Replacements
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In Business For 45+ Years
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Carrier Authorized Dealer
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Emergency HVAC Services
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Family Owned & Operated Business
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NATE Certified Technicians
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In Business For 45+ Years
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Free Estimates on Replacements
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NATE Certified Technicians
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Carrier Authorized Dealer
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Emergency HVAC Services
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Family Owned & Operated Business
Testimonials
Why Our Clients Choose Design-Air Heating & Air Conditioning
A Technician showed up first thing in the morning after I called about my central air unit not working. The Tech troubleshot my situation and got my unit back in business. The customer service was second to none. The Tech was very knowledgeable and had no problem answering the many questions I had.
Design Air was great! Two winters ago my furnace went out. They were out within 2 hours of calling - after hours - and were back early the next day and had it done by early afternoon. Very efficient and caring
I've had the Geothermal system Design-Air put in about a year ago. It's been efficient and quiet. They came quickly to install it and even tied it into my hot water heater. I've been super happy with the professionalism and response by everyone there. I highly recommend them and will continue to let friends and family know about their service.
Called design air when AC unit wasn’t working at 6:00 pm (after hours). The owner called back about 40 minutes later and came to our house to fix the issue by 9:30pm. Great, professional service. Highly Recommend!
A Technician showed up first thing in the morning after I called about my central air unit not working. The Tech troubleshot my situation and got my unit back in business. The customer service was second to none. The Tech was very knowledgeable and had no problem answering the many questions I had.
Design Air was great! Two winters ago my furnace went out. They were out within 2 hours of calling - after hours - and were back early the next day and had it done by early afternoon. Very efficient and caring
I've had the Geothermal system Design-Air put in about a year ago. It's been efficient and quiet. They came quickly to install it and even tied it into my hot water heater. I've been super happy with the professionalism and response by everyone there. I highly recommend them and will continue to let friends and family know about their service.
Called design air when AC unit wasn’t working at 6:00 pm (after hours). The owner called back about 40 minutes later and came to our house to fix the issue by 9:30pm. Great, professional service. Highly Recommend!