KINGFISHER, OK, April 24, 2026 /24-7PressRelease/ -- Dave Hartzell has been selected for inclusion in Marquis Who's Who. As in all Marquis Who's Who biographical volumes, individuals profiled are selected on the basis of current reference value. Factors such as position, noteworthy accomplishments, visibility, and prominence in a field are all taken into account during the selection process.

Mr. Hartzell has established a distinguished career in the heating, ventilation and air conditioning industry as owner and operator of Hartzell's Heat & Air in Kingfisher, Oklahoma, a position he has held since 2008. Over the past 15 years, he has built the company into a leading provider of HVAC services and repairs, specializing in residential systems while also serving gas plants, oil rigs and greenhouses.

Under his leadership, Hartzell's Heat & Air has become recognized as the geothermal expert in Oklahoma, committed to energy efficiency and environmentally friendly solutions. The company is known for significantly reducing energy costs for clients and is a leading dealer of both Trane and Mitsubishi products. The business holds an A+ rating from the Better Business Bureau and has received recognition from Google based on customer reviews. Mr. Hartzell's team of experts has installed and maintained numerous grow houses, some ranging from 200 to 300 tons in size. His approach incorporates best practices learned from previous employers, ensuring superior quality solutions for every client.

Mr. Hartzell strives to make his name synonymous with quality, reflecting a consistently high standard and clear expectations. He believes that excellence must be firmly established before his name is associated with any work. He also emphasizes that his success is a collective achievement, made possible through the steadfast support of his family.

Prior to founding his own company, Mr. Hartzell spent seven years as a network engineer with Sprint. During his tenure, he played a pivotal role in developing a $30 million project that resulted in the creation of the world's largest telecom 12-star triangulation system for cell phones—a national initiative and Federal Communications Commission project of global significance. This achievement stands as his most significant professional milestone, completed under budget and ahead of schedule.

Mr. Hartzell also contributed his expertise to Entech Sales & Service LLC and TD Industries, gaining valuable experience at two of the top 100 firms in the United States. After graduating from Oklahoma State University, he worked alongside a fellow alumnus named Sammy for 12 years, learning business practices and philosophy in a rural setting. His early exposure to the electrical field began at age ten under the guidance of his father, an electrician. By sixteen, Mr. Hartzell was already leading crews while balancing school responsibilities with work on electrical teams during his junior and senior years.

Throughout his career, Mr. Hartzell has demonstrated expertise in residential HVAC systems and is widely regarded as an expert in this area. He maintains active memberships with several industry organizations, including the Better Business Bureau, the Chamber of Commerce, the American Society of Heating, Refrigerating and Air-Conditioning Engineers, the Air Conditioning Contractors of America and the International Ground Source Heat Pump Association.

Academically, Mr. Hartzell's background includes an Associate of Science in thermodynamics from Oklahoma State University, earned in 1989. He also completed vocational training at O.T. Autry Vocational and Technical School in 1986 after attending Woodward High School in Woodward, Oklahoma, graduating in 1981. His academic journey was shaped by influential mentors: his father instilled a strong work ethic and commitment to excellence, his grandfather emphasized the importance of mathematics, and an engineer from General Electric encouraged him to leverage his early electrical experience toward engineering success.

In addition to his professional pursuits, Mr. Hartzell is civically engaged as a donor to various schools within his community. In his free time, he enjoys spending time with family, including his three children, fishing and working with computers—a field where he is recognized as an expert who helped run some of the first bulletin boards and websites while remaining attuned to advancements in artificial intelligence.

As part of his long-term vision for Hartzell's Heat & Air, Mr. Hartzell has structured an exit plan that will transition ownership to employees upon his retirement, ensuring continued success as an employee-owned enterprise with his daughter designated as successor. For now, he is dedicated to teaching others about air conditioning to share knowledge effectively across generations.

About Marquis Who's Who®:
Since 1899, when A. N. Marquis printed the First Edition of Who's Who in America®, Marquis Who's Who® has chronicled the lives of the most accomplished individuals and innovators from every significant field of endeavor, including politics, business, medicine, law, education, art, religion and entertainment. The suite of Marquis® publications, including Who's Who in America® and Who's Who in the World®, remains an essential biographical source for thousands of researchers, journalists, librarians and executive search firms around the globe. Marquis® publications can be viewed at the official Marquis Who's Who® website, www.marquiswhoswho.com.

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