The Passive Solar Energy Book
About this book
"The Passive Solar Energy Book: A Complete Guide to Passive Solar Home, Greenhouse and Building Design," published in 1979 by Rodale Press, is one of the most important popular references for passive solar design to emerge from the energy crisis era of the 1970s. Written by architect and researcher Edward Mazria, the book brought together in accessible form the principles that had been developed by researchers like Victor Olgyay and others in the previous two decades, and made them available to architects, builders, and homeowners seeking to reduce energy consumption through intelligent building design rather than through mechanical systems. The book appeared at a moment of acute public concern about energy.
The oil embargo of 1973-74 and the energy crisis of 1979 had made the dependence of American buildings on fossil fuel heating and cooling visible and economically painful in a way it had never been before. Architects and builders were searching for practical strategies to reduce building energy demand, and passive solar design—using the form, orientation, glazing, and thermal mass of a building to capture and retain solar energy without pumps, fans, or mechanical controls—offered a compelling combination of technical sophistication and low cost. Mazria's book provided a practical manual for implementing these strategies.
The book is organised around a series of "patterns" or design rules—twenty-seven in total—each addressing a specific aspect of passive solar design for residential buildings and small commercial buildings. Each pattern is presented with explanatory text, diagrams, and data, and the rules build on each other to form a coherent and comprehensive design methodology. The fundamental principle of passive solar design, as Mazria presents it, is that the building envelope itself can be designed to act as a solar collector, thermal storage mass, and heat distribution system, with the sun providing the primary heating energy at no operating cost.
The key variables are the orientation of the building (a south-facing orientation in the northern hemisphere maximises winter solar gain), the size and placement of south-facing glazing (which must be calibrated to the climate to avoid overheating), the thermal mass of the building materials (which absorbs solar heat during the day and releases it at night), and the insulation of the building envelope (which reduces heat loss to the outside). The book addresses three principal passive solar system types. Direct gain systems are the simplest: south-facing windows admit solar radiation directly into the living space, where it is absorbed by massive floor and wall materials—concrete, brick, stone, or adobe—and released slowly as heat throughout the night.
Indirect gain systems use a thermal storage wall (often called a Trombe wall after the French engineer Félix Trombe) placed between the south-facing glazing and the interior space; the wall absorbs solar heat and releases it by radiation and convection to the interior. Isolated gain systems use a sunspace or greenhouse attached to the south side of the building; solar heat collected in the sunspace is then conveyed to the interior through windows, doors, or vents. Mazria provides detailed guidance on the sizing of south-facing glazing for different climatic conditions across the United States, using degree-day data and solar radiation maps to allow designers to calculate the appropriate glazing area for specific locations.
He addresses the critical question of summer overheating—the risk that the same south-facing glazing that provides welcome heat gain in winter will overheat the building in summer—and provides rules for the sizing of overhangs and other shading devices that allow winter sun to reach the glazing while blocking the higher summer sun. The book also addresses the design of solar greenhouses and sunspaces, which can serve simultaneously as passive solar heating elements, food-growing spaces, and buffers between the living space and the outdoors. Chapters on natural ventilation and daylighting complete the coverage of passive environmental control strategies.
The book was enormously influential in its time, going through multiple printings and shaping the practice of passive solar design during the late 1970s and 1980s. It is considered a foundational text in the development of sustainable residential architecture in the United States. Sources: Rodale Press; Amazon; Goodreads; Archive.org; Architect Magazine.