Championing the Solar House
February 13, 2019
Based on author and teacher Anthony Denzer, a solar house — one which deliberately utilizes the energy of sunlight for heating spaces — is often considered as a product of the 1970s: “An eccentrically shaped structure using oversized sloped glass walls and also diagonal bamboo siding … an earth berm … a Volkswagen van neighboring”
He admits that this picture is not completely untrue, since many architects tackled house designs in that period that could minimize the use of fossil fuels, ravaged by the petroleum and financial disasters. But it’s an incomplete image.
Denzer’s The Solar House (Rizzoli, 2013) corrects this oversight by forecasting the growth of solar houses in the 1930s to today. It is a narrow subject, but the book is a fun, accessible read. Denzer has created a story of those architects and architects who devoted much of their lives to searching for houses that could utilize less energy, as social and political currents ebbed and flowed with and contrary to them.
A general story of solar houses could be painted because the contradictory attitudes of two fields: the architects’ aesthetic and fascination with passive heating versus the engineers’ technological and busy (mechanistic) focus. This is a place which Denzer spends some time and it is an especially important one, considering that we have not reached a reconciliation that might enable more widespread appreciation of solar houses. This isn’t to say that the story is about a duel of 2 groups. But it is indicative of broader strands in American society — especially concerns of how things seem and how things perform.
Denzer starts the novel with Fred Keck, called the first solar architect. Keck worked with his brother William at the firm Keck + Keck, designing a number of residences in and around Chicago. Many focused on the development of the solar house as a special type. The characteristics they share are linear east-west plans using big, south-facing windows and roof overhangs to block the high sunlight.
Howard Sloan commissioned Fred to design a prototype solar house from the North Shore Chicago suburb of Glenview in 1940. Sloan opened the house to the public, charging a dime entrance to more than 5,000 visitors in four months. He hoped that the cozy interior on cold winter days would persuade people of the virtues of solar houses.
Keck would keep working for Sloan, integrating new materials and technology (triple-pane glazing to decrease heat loss from inside to outside during the nighttime, radiant heating etc.) at a 24-house subdivision they called Solar Park. Keck had developed operable and insulated louvers which were often beneath the south-facing glass; these assemblies permitted for ventilation throughout the day while helping keep the interior temperature during the nighttime when closed.
Pictured is the Duncan House in another Chicago suburb, Flossmoor. It included the very same components (linear plan, south-facing windows, roof overhangs) but also exterior “wing walls” using adjustable vertical louvers for cutting back on the late-afternoon sun in the months when overheating of the interior occurred.
The Keck brothers were not really known for its solar houses they developed from the 1940s (they had been omitted from Sigfried Giedion’s influential Space, Time and Architecture although he toured their houses). Instead it was a few houses Fred Keck made for the 1933 Century of Progress fair in Chicago, both glass houses rather than solar. The House of Tomorrow (photograph) and Crystal House both featured all-glass outside walls with blinds and drapes, respectively, for shading.
The houses were extremely popular, but their intent and appeal were formal rather than practical; they pointed to an alternative future through the use of glass. However, Keck did recognize the benefits of solar heating, which led him to develop houses within the next decade using much more selective glazing. With so much single-pane glass, the House of Tomorrow would overheat during the day and lose heat during the night, something which didn’t dissuade Mies van der Rohe and Philip Johnson from producing ineffective glass houses almost 20 years after.
The solar houses that pepper Denzer’s book consequently resemble the 1970s stereotype, rather than glass houses, but they’re the 1970s typology in the making. There is a Frank Lloyd Wright “hemicycle” house, a similar but inverted curved house by the Keck brothers, amid work by less-known architects that created houses inside academic institutions or for companies which would benefit from the implementation of solar houses. In the latter vein, Libby-Owens-Ford commissioned notable architects to design solar houses for each of the 48 states at the time; at the end just a publication of these designs was produced, not the actual houses, but the initial hopes were high.
Architect Henry Wright’s renovation of this Ramirez House at Pennsylvania (photograph) employs the same principles as the Kecks’ pioneering work. However, its wood floor didn’t allow for the sun’s energy to be saved and released later, as happens in concrete flooring. From talks of the house came an emphasis on thermal mass as an significant part solar houses.
Many schools worked on developing solar house designs, especially MIT using its own numbered series of house designs starting in 1939. As can be viewed here, Solar House I, developed by engineer Hoyt Hottel, concentrated on technology over architecture.
The south-facing roof was covered in flat-plate collectors, or heat traps, which Denzer defines as “a shallow vessel, comprising three glass places split by airspace, a black-painted copper plate backed by copper tubes of water, and 51/2 inches of mineral wool insulation” The sun would heat the plates and so the water, knowingly heating the distances through mechanical way.
Maria Telkes an engineer at MIT who developed an alternative scheme to Hottel’s, worked with architect Eleanor Raymond to a house using a similar reliance on technology but one whose kind and aesthetics would likewise benefit the layout. The Dover Sun House positioned Telkes’ collectors (created with phase-change salt containers) above south-facing windows, so the residents could have views and the sun’s heat will be saved to heat the interior via bins above the ceiling.
A testament to the popularity of this Dover Sun House, in addition to the desire for houses that could use less energy at the postwar years, can be seen at a cover story of Popular Science at 1949. Unfortunately the system lasted just two years, because of the sedimentation of the solid and liquid sodium and the corrosive effects of the component on the bins.
The attempts on the part of engineers and architects growing solar houses in the years before and after World War II culminated from the 1955 World Symposium on Applied Solar Energy and the 1957 Solar Energy exhibition at Greece. So many solar houses were built after 1955 that, as Denzer states, “documentation could be impossible,” but it wasn’t enough to stave off the low cost of electricity and the growth of air conditioning in these years.
Nevertheless, Denzer presents some novel projects from such years, such as engineer Masanosuke Yanagimachi’s Solar House II in Tokyo. The interior resembles that of a traditional Japanese house, with tatami mats and translucent panels, but in addition, it has radiant ceiling panels functioned by rooftop heat traps, as in Hottel’s MIT design.
Yanagimachi’s Solar House II is among many projects documented in the publication with architectural drawings. This building section illustrates how the systems are tied together, in the rooftop heat sink and radiant ceiling panels to the innovative heating tank in the cellar.
The latter was used for both heating and cooling; in the case of heating, the heat pump created ice during the night which was used the next day to cool the water pumped through the house. The idea of off-peak ice storage has become increasingly common in green buildings, even in skyscrapers.
Denzer calls for the late 1970s a “Solar Renaissance,” suitable given that Jimmy Carter mounted solar hot-water panels atop the White House in 1979 (to be removed by Ronald Reagan seven years later). Among those jobs from this time period is Saskatchewan Conservation House, that resembles early solar houses in form but departs from them in important ways: It’s smaller and fewer windows, it doesn’t rely on most of the engineered technologies in the prior decades, and it is superinsulated. The latter feature is its most lasting, influencing the current Passivhaus fundamentals and Canada’s R-2000 app.
The basic idea of the superinsulated and supertight house is that the heat inside the interiors (some of it coming from solar gain) is not lost to the exterior. Fresh air is brought in by an air-to-air heat exchanger, as is the case from the Conservation House. The house performed so well — attaining what could be referred to as net-zero status — which the solar collectors mounted above the second-floor windows could have been omitted, as they were not needed for space heating.
Denzer finishes the book with a few snapshots of solar houses today. These fall to the superinsulated camp of houses created to Passivhaus fundamentals, like this 1991 house in Germany by Wolfgang Feist and others; and the biennial Solar Decathlon contests, where student teams design and build houses that vie to be the roughest at a number of measured manners. The latter more closely resemble the pioneering work of this Kecks, however, the work from the competitions also attempts to synthesize architectural and engineering considerations, arising through multidisciplinary teams and incorporated layout.
The Solar House
It is apparent from Denzer’s publication that there is more to solar houses than previously known or imagined. However, it’s also obvious that there is still lots of work that should be performed to synthesize the aesthetic and the technological, and also to persuade the people that solar houses are viable and desirable.
Increasing energy prices may create solar houses more desirable in the last few years and decades to come, so it’s time for architects and engineers to work together on producing solutions that tap into these Denzer so eloquently presents.
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