Hoyt Hottel

Hoyt Clarke Hottel (January 15, 1903, Salem, IN — August 18, 1998, Winchester, MA) was a chemical engineer who spent 76 years on the MIT faculty and shaped both combustion science and solar energy research in the twentieth century.

Education and MIT career

Hottel earned his BSc in chemistry from Indiana University in 1922 and his SM in chemical engineering from MIT in 1924. He became the first Carbon P. Dubbs Professor of Chemical Engineering and directed MIT’s Fuels Research Laboratory for 35 years. During World War II, he served as chief of incendiary bomb development for the U.S. military.

Solar research

Hottel chaired MIT’s Solar Energy Research program from 1938 to 1964, overseeing the design and construction of MIT Solar Houses I through IV, a series of experimental buildings that tested flat-plate collector systems and water-based thermal storage. With Bliss Whillier, he developed the Hottel-Whillier model of flat-plate collector performance, which became a foundational tool in solar thermal engineering.

Rivalry with Telkes

Hottel’s most consequential professional conflict was with colleague Maria Telkes over heat storage media. Hottel insisted on water; Telkes championed Glauber’s salt, a phase-change material. When the Dover Sun House‘s Glauber’s salt system failed by its third winter, Hottel influenced a review that led to Telkes’s departure from MIT in 1953. The dispute reflected a deeper tension between incremental engineering and ambitious experimentation that ran through mid-century solar research.

Despite his decades of solar work, Hottel remained skeptical of solar energy’s near-term commercial viability, warning against “kidding the public about the sun.”

Recognition

Hottel received the Medal for Merit in 1948 for his wartime contributions and was inducted into the Solar Hall of Fame in 1977. His influence on Timothy Maloney‘s water-wall module work, alongside Steve Baer, connected him to the New Mexico passive solar lineage.

See also

• Maria Telkes
• Dover Sun House
• Timothy Maloney
• Steve Baer
• Dover Sun House — place record for the 1948 house whose Glauber’s-salt failure fueled his dispute with Telkes
• Eleanor Raymond — architect of the Dover Sun House at the center of the Telkes storage dispute