About Dr. Fahrenheit, HVAC

HVAC & Refrigeration Specialists

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An appointment

    Trust our team of experts for fast, dependable AC repair, service, and installation.

    “Bringing back the old-fashioned house call.”

    Dr. Fahrenheit is an HVAC company focused on heating, cooling and refrigeration. 

    We’re a veteran-owned, family-operated business that has been proudly serving clients in Woodstock, Roswell, Marietta and Acworth for over twenty years. 

    We’re dedicated to our community and offer discounts for senior citizens, veterans, and more. We’re your friendly mom and pop shop who love to support our friends, neighbors and fellow community members. 

    About our Owners:
    Randall and Laura Lahr

    Dr. Fahrenheit was started by husband and wife team Randall and Laura Lahr in 2001. With Randall’s HVAC experience and Laura’s construction and sales experience, they developed a dream–a dream on which they have raised their children and lived a blessed life.


    Randall Lahr is a proud Marine Corp Veteran with a passion for service and his fellow brothers and sisters in arms. He is a proud supporter of the Wounded Warrior project and member of the Marine Corps League of Woodstock. In 2018, Mr. Lahr was involved in a horrific motorcycle accident, and by the grace of God, he survived. 


    With an “Ooh-rah,” he set out to “adapt and overcome” and today, with a dedicated team that shares a common mission, Randall builds his business on that of honor, courage and commitment. The dream continues…                                                                          

    Request an Appointment

    Contact us today to schedule a service appointment or free estimate.

    Contact Us

    Our Values

    Superior Customer Service

    Dr. Fahrenheit HVAC is a small but mighty team dedicated to being focused on our clients and delivering the absolute best customer service, guaranteed.

    Clear and Honest Communication

    We believe clear, honest communication is a key factor in providing excellent service. When you voice your questions or concerns, we listen.


    Our goal is to make you comfortable! That means we'll work with you to make sure the job is done right the first time and that all your needs are met.

    Cherokee County HVAC Repair and Replacement Services

    Our team offers high-quality work performed by professionals you can trust.

    Air Conditioning Services

    Our certified technicians keep your air conditioning systems working efficiently during the scorching Georgia summers.

    We’re the reliable team you can trust to make sure your air conditioning repairs and replacements are done right the first time. Our services include: 

    • Air conditioning maintenance
    • Air conditioning replacement 
    • Air conditioning installation 
    • Air conditioning repair

    Heating Services

    When the temperatures dip in the winter months, we know that a home without a properly working heater can be a problem–and quick! Our dedicated technicians will come out, take the time to understand the issues, and help you get your home toasty again. Heating services include:


    • Heating maintenance 
    • Heating replacement 
    • Heating installation
    • Heating repair

    24/7 Emergency HVAC Services

    In addition to our heating and cooling services, we understand that sometimes, your units just break or cause problems, no matter what time of day it is. That’s why we also offer 24/7 emergency service on HVAC repairs. Just give us a call! 

    Why Dr. Fahrenheit?

    What our customers say.

    Makes and Models

    We work with all major brands and models of HVAC equipment. The doc will diagnose your issue and have the perfect antidote for your HVAC issues.

    Contact Us

    Need help? Schedule your appointment online here or give us a call at (770) 926-6773. Give us a call to experience the Dr. Fahrenheit difference!

      The cold temps are here–is your heating system up to the challenge of keeping you toasty during the cold months ahead?

      Furnace Health Check Special:
      Get Up To $500 Back On Select Installed HVAC Systems Now Through 12/15.

      Did you know? The cost of replacing your old furnace or heating system to install a new one will be offset over time by the money you save with a more efficient unit. A new furnace installation performed by one of our certified professionals will help keep your house warm and cozy during the cold winter season. 

      If you think it may be time to replace your old heating unit, schedule a FREE in-home consultation with Dr. Fahrenheit and one of our authorized heating technicians will come out to give you an estimate on the cost of installing a new furnace. 

      We offer high-quality systems from the world’s leading brands like Trane, Rheem, American Standard, and more. 

      Ensure your toes stay toasty this winter. Book your FREE house call today!