John I. Yellott
Encyclopedia
John I. Yellott was a scientist internationally recognized as a pioneer in passive solar energy, and an inventor with many patents to his credit. In his honor the American Society of Mechanical Engineers
(“ASME”) Solar Division confers a biannual "John I. Yellott Award" which "recognizes ASME members who have demonstrated sustained leadership within the Solar Energy Division, have a reputation for performing high-quality solar energy research and have made significant contributions to solar engineering through education, state or federal government service or in the private sector."
, where he was chairman of the Department of Mechanical Engineering from 1940 to 1943 and director of the Institute of Gas Technology from 1943 to 1945. During World War II he was assigned to the Manhattan Project
to work on the development of atomic weapons as a consultant to the Metallurgical Laboratory of the University of Chicago
.Curriculum Vitae, John Ingle Yellott (1985) PDF file provided courtesy Dr. John I. ("Jack") Yellott, Jr.
". Soon after the oil crisis, Arizona State's College of Architecture instituted a solar program and chose Yellott as its head; he continued to teach there until his retirement at age 70.
. He served as a consultant to major industrial concerns such as Corning Glass, PPG Industries, Libbey-Owen-Ford Glass company, Shatterprufe Glass Company of Port Elizabeth, South Africa; and Pilkington Brothers Glass Company of Great Britain. One of Yellott's clients was Northrup, Inc. whose founder Leonard L. Northrup Jr.
was introduced to solar technology by Yellott, and whose company went on to develop some of the first solar air conditioning
systems and heliostat
s, under Yellott's on-going advice.
According to his Illinois Institute of Technology
Hall of Fame entry, Yellott's work resulted in more than fifty patents, such as an electric locomotive with a coal fired gas turbine using pulverized coal directly injected into a combustion chamber; a film-type solar water heater and a transparent cover to heat swimming pools by trapping solar radiation Yellott's pool cover idea remains in commercial use to this day. He also contributed his solar expertise to civic projects such as the landmark Carefree Sundial in Carefree, Arizona
.
Yellott pioneered passive solar cooling as a field parallel to solar heating, with particular attention to water spray and controlled evaporation. As with any innovator, not all experiments met with success.
Yellott's collaboration with solar entrepreneur Harold Hay on developing an evaporative solar system called a roofpond, which Yellott considered "the simplest system which can accomplish both heating and cooling with the same equipment,” proved to be not so simple. The experiments at Yellott's laboratory encountered obstacles such as the unexpected "healthy growth of 'wrigglers' within plastic-enclosed water" from the city mains; then "a pair of nesting birds was attracted to the comfort of a projecting portion of the roofpond. . . ." (The researchers eliminated the unwelcome 'wrigglers' as well as a prolific growth of algae with chemical treatment; they considered the “cheerfulness of the birds a pleasant relief from the drudgery of data-collection,” but recommended “preventive measures for those not wanting such company.”)
Yellott's and Hay's experiments did prove the roofpond concept technically feasible, later confirmed with expanded testing on dormitory roofs at Trinity University
in Texas. Nonetheless, in the words of solar scientist Kenneth Haggard of the San Luis Obsispo Solar Group, implementation of the idea of maintaining a large puddle of water on one's roof to cool the interior "awaits the next period of blossoming of passive solar architecture." (Hay defended roofponds, acknowledging that while a roofpond design error proved "highly expensive to a young architect and his client," nonetheless there is an "unnecessary fear of having bodies of water overhead." Hay also noted that a review of all roofpond installations in the United States concluded the roofpond "outperforms any other single passive system in both heating and cooling modes" and opined "It may be DOE's best kept-secret buried under hundreds of reports.")
Yellott's achievements particularly in the area of glazing and solar radiation capture have stood the test of time. According to Dr. Jeffrey Cook, College of Architecture and Design, Arizona State University, writing the introduction to the Passive Solar Journal's John I. Yellott Memorial issue, "he made major contributions in areas of basic research, instrumentation, analytic methods, applications, collaboration, education, and demonstration." Cook also wrote: "[h]e published no definitive book," but "[a]rticles bearing Yellott's name will remain classics in solar energy literature;" he "developed no distinctive demonstration, no outrageous solar machine, and no landmark building or award winning engineering system," yet "as a consultant he influenced such major achitectural feats as the St. Louis Arch and the new Hong Kong and Shanghai Bank;” his analysis “contributed to the industry development of architectural glasses . . . that have gained worldwide use.” His pervasive influence in solar science is largely found in the ongoing work of others, as “he was a mentor to architects, inventors, and students.” "Thus,” Cook concluded, “as gentle and persuasive as the sun, Yellott touched many people and places."
Yellott died of a heart attack in Phoenix in 1986, survived by his (second) wife Barbara, a son and a daughter, two stepsons and six grandchildren.
American Society of Mechanical Engineers
The American Society of Mechanical Engineers is a professional body, specifically an engineering society, focused on mechanical engineering....
(“ASME”) Solar Division confers a biannual "John I. Yellott Award" which "recognizes ASME members who have demonstrated sustained leadership within the Solar Energy Division, have a reputation for performing high-quality solar energy research and have made significant contributions to solar engineering through education, state or federal government service or in the private sector."
Early life, education, academia, and war service
John Ingle Yellott was born in Bel Air, Maryland, the son of the Reverend Dr. John I. (1873-1935) and Mildred Walker Nelson Yellott (1876-1954). He was educated at Bel Air High School and Episcopal High School in Alexandria, Virginia, and then studied Mechanical Engineering at Johns Hopkins University, Baltimore, receiving his M.E. in 1931 and his M.M.E. with distinction in 1933. Yellott embarked on a career in academia at the Stephens Institute of Technology, Hoboken, and at Illinois Institute of TechnologyIllinois Institute of Technology
Illinois Institute of Technology, commonly called Illinois Tech or IIT, is a private Ph.D.-granting university located in Chicago, Illinois, with programs in engineering, science, psychology, architecture, business, communications, industrial technology, information technology, design, and law...
, where he was chairman of the Department of Mechanical Engineering from 1940 to 1943 and director of the Institute of Gas Technology from 1943 to 1945. During World War II he was assigned to the Manhattan Project
Manhattan Project
The Manhattan Project was a research and development program, led by the United States with participation from the United Kingdom and Canada, that produced the first atomic bomb during World War II. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army...
to work on the development of atomic weapons as a consultant to the Metallurgical Laboratory of the University of Chicago
University of Chicago
The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...
.Curriculum Vitae, John Ingle Yellott (1985) PDF file provided courtesy Dr. John I. ("Jack") Yellott, Jr.
Changing fields
After the War Yellott served as Director of Research, Locomotive Development Committee, Bituminous Coal Research from 1945 until 1955. In 1955 at age 47 after having already achieved recognition in steam, coal, gas, and nuclear energy, he switched fields—to passive solar energy. Yellott said the change resulted from "the realization that the entire world, and the United States in particular, was running out of fluid fuels, and that we must find a way to gain economic access to the limitless energy of the sun." In a 1974 interview with Popular Science Magazine Yellott said he anticipated soon "[t]he inexorable forces of economics will bring about the age of solar energy."Industrial consulting and return to academia
In June 1958 Yellott founded John Yellott Engineering Laboratories, and the Yellott Solar Energy Laboratory, in Phoenix, Arizona. He became an industrial consultant, with a primary focus on reflective glazing. He served as Headmaster and then Director of Development for Phoenix Country Day School, and taught environmental control systems at the College of Architecture at Arizona State University. As the first Chairman of the ASME Solar Energy Applications Group (later Solar Energy Division) he was in a position of leadership "that was critical to the official 'rediscovery' of solar energy following the 1973 oil crisis1973 oil crisis
The 1973 oil crisis started in October 1973, when the members of Organization of Arab Petroleum Exporting Countries or the OAPEC proclaimed an oil embargo. This was "in response to the U.S. decision to re-supply the Israeli military" during the Yom Kippur war. It lasted until March 1974. With the...
". Soon after the oil crisis, Arizona State's College of Architecture instituted a solar program and chose Yellott as its head; he continued to teach there until his retirement at age 70.
Solar engineering
Yellott's early interest, the source of much consulting work, was on the transparency and transmissivity of glass. In 1960s he helped to develop the solar heat gain factor (SHGF) method of calculating the passive thermal role of glass, now the standard method accepted by the American Society of Heating, Refrigerating and Air-Conditioning EngineersAmerican Society of Heating, Refrigerating and Air-Conditioning Engineers
The American Society of Heating, Refrigerating and Air Conditioning Engineers is an international technical society for all individuals and organizations interested in heating, ventilation, air-conditioning, and refrigeration...
. He served as a consultant to major industrial concerns such as Corning Glass, PPG Industries, Libbey-Owen-Ford Glass company, Shatterprufe Glass Company of Port Elizabeth, South Africa; and Pilkington Brothers Glass Company of Great Britain. One of Yellott's clients was Northrup, Inc. whose founder Leonard L. Northrup Jr.
Leonard L. Northrup Jr.
Leonard "Lynn" L. Northrup Jr. is a pioneer of the commercialization of solar thermal energy in the United States. Influenced by the work of Professor John Yellott, Dr...
was introduced to solar technology by Yellott, and whose company went on to develop some of the first solar air conditioning
Solar air conditioning
Solar air conditioning refers to any air conditioning system that uses solar power.This can be done through passive solar, solar thermal energy conversion and photovoltaic conversion . The U.S...
systems and heliostat
Heliostat
A heliostat is a device that includes a mirror, usually a plane mirror, which turns so as to keep reflecting sunlight toward a predetermined target, compensating for the sun's apparent motions in the sky. The target may be a physical object, distant from the heliostat, or a direction in space...
s, under Yellott's on-going advice.
Illinois Institute of Technology
Illinois Institute of Technology, commonly called Illinois Tech or IIT, is a private Ph.D.-granting university located in Chicago, Illinois, with programs in engineering, science, psychology, architecture, business, communications, industrial technology, information technology, design, and law...
Hall of Fame entry, Yellott's work resulted in more than fifty patents, such as an electric locomotive with a coal fired gas turbine using pulverized coal directly injected into a combustion chamber; a film-type solar water heater and a transparent cover to heat swimming pools by trapping solar radiation Yellott's pool cover idea remains in commercial use to this day. He also contributed his solar expertise to civic projects such as the landmark Carefree Sundial in Carefree, Arizona
Carefree, Arizona
Carefree is a town in Maricopa County, Arizona, United States. According to 2006 Census Bureau estimates, the population of the town is 3,799.-History:...
.
Yellott's collaboration with solar entrepreneur Harold Hay on developing an evaporative solar system called a roofpond, which Yellott considered "the simplest system which can accomplish both heating and cooling with the same equipment,” proved to be not so simple. The experiments at Yellott's laboratory encountered obstacles such as the unexpected "healthy growth of 'wrigglers' within plastic-enclosed water" from the city mains; then "a pair of nesting birds was attracted to the comfort of a projecting portion of the roofpond. . . ." (The researchers eliminated the unwelcome 'wrigglers' as well as a prolific growth of algae with chemical treatment; they considered the “cheerfulness of the birds a pleasant relief from the drudgery of data-collection,” but recommended “preventive measures for those not wanting such company.”)
Yellott's and Hay's experiments did prove the roofpond concept technically feasible, later confirmed with expanded testing on dormitory roofs at Trinity University
Trinity University (Texas)
Trinity University is a private, independent, primarily undergraduate, university in San Antonio, Texas. Its campus is located in the Monte Vista Historic District and adjacent to Brackenridge Park....
in Texas. Nonetheless, in the words of solar scientist Kenneth Haggard of the San Luis Obsispo Solar Group, implementation of the idea of maintaining a large puddle of water on one's roof to cool the interior "awaits the next period of blossoming of passive solar architecture." (Hay defended roofponds, acknowledging that while a roofpond design error proved "highly expensive to a young architect and his client," nonetheless there is an "unnecessary fear of having bodies of water overhead." Hay also noted that a review of all roofpond installations in the United States concluded the roofpond "outperforms any other single passive system in both heating and cooling modes" and opined "It may be DOE's best kept-secret buried under hundreds of reports.")
Yellott's achievements particularly in the area of glazing and solar radiation capture have stood the test of time. According to Dr. Jeffrey Cook, College of Architecture and Design, Arizona State University, writing the introduction to the Passive Solar Journal's John I. Yellott Memorial issue, "he made major contributions in areas of basic research, instrumentation, analytic methods, applications, collaboration, education, and demonstration." Cook also wrote: "[h]e published no definitive book," but "[a]rticles bearing Yellott's name will remain classics in solar energy literature;" he "developed no distinctive demonstration, no outrageous solar machine, and no landmark building or award winning engineering system," yet "as a consultant he influenced such major achitectural feats as the St. Louis Arch and the new Hong Kong and Shanghai Bank;” his analysis “contributed to the industry development of architectural glasses . . . that have gained worldwide use.” His pervasive influence in solar science is largely found in the ongoing work of others, as “he was a mentor to architects, inventors, and students.” "Thus,” Cook concluded, “as gentle and persuasive as the sun, Yellott touched many people and places."
Yellott died of a heart attack in Phoenix in 1986, survived by his (second) wife Barbara, a son and a daughter, two stepsons and six grandchildren.
Awards, honors, and tributes
- The Most Excellent Order of the British EmpireOrder of the British EmpireThe Most Excellent Order of the British Empire is an order of chivalry established on 4 June 1917 by George V of the United Kingdom. The Order comprises five classes in civil and military divisions...
, Member, civil division - The Most Venerable Order of the Hospital of St John of Jerusalem, Associate Commander
- Illinois Institute of TechnologyIllinois Institute of TechnologyIllinois Institute of Technology, commonly called Illinois Tech or IIT, is a private Ph.D.-granting university located in Chicago, Illinois, with programs in engineering, science, psychology, architecture, business, communications, industrial technology, information technology, design, and law...
Hall of Fame - Fellow of ASME, ASHRAE, AAAS, and the Arizona Academy of Science
- Benjamin Franklin Fellow, Royal Society of ArtsRoyal Society of ArtsThe Royal Society for the encouragement of Arts, Manufacturers and Commerce is a British multi-disciplinary institution, based in London. The name Royal Society of Arts is frequently used for brevity...
, London - Honorary doctorate conferred by Arizona State UniversityArizona State UniversityArizona State University is a public research university located in the Phoenix Metropolitan Area of the State of Arizona...
1985 - John I Yellott, Ambassador of the Sun, Proc. 12th National Passive Solar Conf., Boulder, Co. American Solar Energy Society, 1987 pp 1–8 (J. Cook, author)
- John Yellott: A Tribute, Solar Today, Vol. 1, No. 1, Jan/Feb. 1987. pp 4–5 9J. (J. Cook, author).
- Editorial: Remembering John Yellott. Passive Solar Journal, Vol. 3, No. 4, 1986, p. 327 (R.W. Jones, author).
- In Memoriam; John Ingle Yellott. SunWorld, Vol. 11, No. 2, 1987, pp. 32–33 (B. Yellot, author).
- In Memoriam: Dr. John Yellott 1908-1986. Solar Energy, Vol. 30, No. 6., 1987. pp. 387–388 9P.( Glasser, author).
- The American Solar Energy SocietyAmerican Solar Energy SocietyThe American Solar Energy Society is an association of solar professionals and advocates in the United States. Founded in 1954, ASES is dedicated to inspiring an era of energy innovation and speeding the transition toward a sustainable energy economy...
confers annually a John and Barbara Yellott Award to a graduate student concentrating on solar energy.
See also
- Solar architecture
- Solar design
- Passive Solar
- Passive coolingPassive coolingPassive cooling refers to technologies or design features used to cool buildings without power consumption, such as those technologies discussed in the Passive house project.-Passive cooling:...
- Cool roofCool roofCool roofs are the roofs that can deliver high solar reflectance and high thermal emittance...
- Leonard L. Northrup Jr.Leonard L. Northrup Jr.Leonard "Lynn" L. Northrup Jr. is a pioneer of the commercialization of solar thermal energy in the United States. Influenced by the work of Professor John Yellott, Dr...