David Crosthwait

David Crosthwait was a pioneer in the heating, ventilation and air conditioning (HVAC) industry. He devoted his career, which included groundbreaking efforts in engineering, inventing, writing and teaching, to redefining the technology of indoor climate control. His many contributions to the HVAC industry paved the way for the efficient systems on which we rely today.

Crosthwait was born in Nashville, Tennessee, in 1898. He grew up in Kansas City, Missouri, where his father worked as a biology and chemistry teacher and became principal of the city’s first Black high school. Crosthwait, who showed an early interest in engineering and a passion for invention, earned a full academic scholarship to Purdue University.

At Purdue, Crosthwait studied mechanical engineering, earning his bachelor’s degree in 1913 and his master’s degree in 1920. After completing his degrees, he joined C.A. Dunham Co. (now Dunham Bush) in Marshalltown, Iowa, in 1925. Founded in 1894, the company is one of the oldest commercial heating and air conditioning unit manufacturers in the world. Here, Crosthwait worked as a research engineer and began developing new products to heat and ventilate buildings. He became the company’s director of research laboratories in 1930.

During the 1920s and 1930s, Crosthwait developed many inventions, including an improved boiler system and a new thermostat control, with the goal of making the ventilation systems in larger buildings more effective. His innovative solutions to heating and ventilation problems led him to be commissioned to design systems for high-profile projects. Most significantly, he designed the steam system used to heat Radio City Music Hall at Rockefeller Center in New York City.

Crosthwait earned 39 U.S. patents and 80 international patents. His inventions spanned the HVAC industry and beyond, including innovations in refrigeration, auto turn signals, thermostat controls, vacuum pumps and more.

A regularly published author in heating and ventilation industry publications, Crosthwait contributed chapters to the American Society of Heating, Refrigerating and Air Conditioning Engineers Guide. He also authored a manual on heating and cooling with water and contributed to many guides, standards and codes dealing with HVAC and refrigeration systems.

After more than 40 years at Dunham Bush, where he had become the technical adviser, Crosthwait retired in 1971.

Following his retirement, Crosthwait continued to share his expertise by teaching a course on steam heating theory and control systems at Purdue, where he would receive an honorary doctorate in 1975.

Crosthwait was named a fellow of the American Society for the Advancement of Science and served as a member of the American Chemical Society and the National Society of Professional Engineers. In 1971, he became the first Black fellow of the American Society of Heating, Refrigeration and Air Conditioning Engineers.