Originally published on Green Building Elements.
The evolution of pioneer solar passive architect David Wright’s career demonstrates the importance of exposure to the solar works of the ancients, as provided in this guest column by John Perlin based on his new book, Let It Shine: The 6000-Year Story of Solar Energy. This is the first of five articles.
David Wright was just another young architect trained conventionally in what he described as the school of just build it and then with heating and cooling equipment and lots of fuel you combat nature. An outing to the Betatakin cliff dwellings at the Navajo National Monument marked the beginning of a new way he would regard architecture.
From a northern creek bed vista, Wright craned his neck to view an entire village nestled in a cave that had been carved out of a cliff by the forces of erosion and opened to the south. Temperatures were around 40 degrees Fahrenheit but the interpretive guide informed him that the interiors of the structures that once housed the villagers hovered between 70 to 80 degrees Fahrenheit and never dropping below 50 degrees at night. The low winter sun, the ranger explained, poured into the cave throughout the day. The thick walls of the houses absorbed the sunlight and its heat moved through the walls at such a pace as to reach the living spaces by sunset, keeping the villagers sufficiently warm with little need for any other fuel. Building with the sun and climate in mind, the ranger continued, allowed those inside to survive where almost no firewood was readily available, owing to what he referred to as their ancestors’ shortsightedness.
A new vision began to take hold in Wright’s mind. He began to see the deserted village as “a very sophisticated use of low-energy materials and natural elements for year-long living comfort.” Wright began to appreciate their maximal use of readily available resources with an absolute minimum of technology, and it worked as the ancient cave dwellers had only the cave and rock with which to make their buildings energetically self-sufficient. That fact, he swears, he would never forget. “That impressed me.” Further research revealed that other ancient peoples had dwelled in variations on the same theme. “Looking back and drawing from history, it becomes increasingly apparent that the really hard work has already been done,” Wright concluded.
When Wright considered that he had at his disposal a far greater range of analytical tools and materials to work with than had his predecessors, Wright felt confident that he could rely on the house itself to stay sufficiently warm in winter and comfortably cool in winter if properly built and oriented
In 1972 Wright designed and built a house with a two-story glass wall that formed the entire south side. The depth of the house was calculated so that the sun would penetrate the entire interior in winter while the eave extended sufficiently to keep out the high summer sun. The house’s thick adobe walls were insulated on the outside with polyurethane foam to protect those living inside from the winter cold and the summer heat. The roof was also heavily insulated, and the floor consisted of a relatively massive layer of adobe brick and sand with rigid insulation underneath. Tight fitting, folding shutters were opened and closed as necessary for indoor comfort.
Before Wright had finished the house, his scientific friends from Los Alamos Laboratories were worried, saying, “It might not work as well as you think!” They warned and advised him to install an auxiliary heating system. Much to their surprise, heat from his Franklin stove sufficed, having to burn only a fraction of what others usually required to stay comfortably warm during that cold, snowy Santa Fe winter.
Sitting inside the toasty house one winter evening, Wright and some of his solar-minded friends that included the legendary Steve Baer were chatting. Wright asked the group: “So what type of system have I built?” One of the engineers replied, “Well, in mechanical engineering. We call systems that use pumps or fans ‘active,’ so I guess this must be a passive solar design.” Wright later recalled that it was the first time he had ever heard the term passive solar mentioned, adding “today passive solar design is known and practiced throughout the world.
Photographs: David Wright, National Park Service
Author: John Perlin is author of four books: “A Golden Thread: 2500 Years of Solar Architecture and Technology;” “A Forest Journey: Wood and Civilization;” “From Space to Earth: The Story of Solar Electricity;” and his latest book, “Let It Shine: The 6000-Year Story of Solar Energy.” Harvard University Press Chose “A Forest Journey” as one of its “One-Hundred Great Books” published by the press, as well as a “Classic in Science and World History.” The Geographic Society and the Sierra Club chose the book as their “Publication of the Year.” “Power of the Sun” and “Sunrise” are two documentaries for which I did the screenplays. “Power of the Sun” was done in collaboration with two Nobel Laureates at University of California, Santa Barbara, where I am now a member of the Department of Physics.