Passive Solar Architecture Uses building elements for energy capture and storage Windows for solar gain, daylighting, ventilation Overhangs, fins, and shading for solar control Convective, radiant sky, or evaporative cooling Work even when the power is out!

Passive Solar Architecture First described in Greece and Rome Driven by rising charcoal prices Widespread use of solar design Solar cities, solar access, passive heating and cooling If our designs are to be correct we must...take notice of the countries and climates in which they are built. Vitruvius

Solar cities develop Planning and street layout Building orientation Passive design improved comfort and the quality of life

Summer comfort A well to do Roman family would have fountains and pools for summer cooling Today we might use an indirect evaporative cooler

Passive Heating 1.0 Most people first think of passive solar heating This is easy - face south, add windows or a solar room or conservatory Bodie, California 1930s

1930 Swiss Solar Fuel shortages and high costs after WWI led to solar design in Germany and Switzerland Neubühl, near Zurich, is a cooperative solar village

1940s Solar USA George Fred Keck designed Solar Park homes for Howard Sloan in 1941 Good orientation for winter, solar control in summer but under-insulated, not enough mass Illinois was the home of Libby-Owens-Ford a double pane glass maker who supported solar development

1950 Solar Sustainable A rammed earth passive solar home was built in 1950 by David and Lydia Miller in Greeley, Colorado The owners and architect J Palmer Boggs were delighted with performance

1951 Solar Design Tools Architects in the 1950s had solar design tools for the first time Solar homes were built, primarily by architects for the well-to-do But subsidized electricity, low cost air conditioning, and mass production soon killed solar design

Passive heating 2.1 The next step was adding more thermal mass to store energy for heat at night in winter A concrete floor or plaster walls provide some mass But more may be needed

1956 Mass Wall -- France Masonry wall for thermal mass Glazing outside gathers solar energy Vents allow heat in/reduce night loss American Edward Morse 1880s Rediscovered in France by Félix Trombe Trombe wall Trombe Wall - Odiello

1961 Passive Solar School Wallasey, England--Emslie Morgan, architect The first effective large passive solar design Double glazing, high mass with external insulation Good interior daylighting Students, sun and lights provided all the heat

1972 Water Is Often Best Steve Baer built this high performance water wall home Corrales, New Mexico His company, Zomeworks, is still active today

1976 Water wall This water tank was the first rectangular water wall, 1976 Mass floor, solar orientation and overhangs for solar control Also 3 tank ICS solar water heater Energy use 90% below average

Passive heating 2.2 Better insulation, more mass Water wall passive home (DAB solar design) Smaller rectangular steel water tanks Energy use cut 75%

Cooling 3.0 - Solar Control Overhangs work on south facing walls East and west may need fins, shutters, awnings, shades Toldos cover courtyards Landscaping helps, trees to SE/SW not south Green walls

Cooling - Night Vent Night convective cooling Water wall office, Jon Hammond 1975 Culverts add surface area for improved heat exchange Cross and stack ventilation during the day can also provide cooling by evaporation

Enhanced ventilation Traditional designs also utilized ventilation, often with evaporative cooling for a boost In Iran cool air may be drawn from underground water tunnels (qanats) Fountains and pools enhanced cooling breezes

Integrated Design 4.0 ICS water heaters Greg Acker designed this culvert water wall home Solar control, night vent cooling Direct gain solar heating with a water wall 70% savings on energy use Roll down awning-summer Water filled culverts behind

Roof mass integrated design Roof mass can be heated in winter by the sun Cooled in summer at night Water or highmass material

100% Heating and Cooling Harold Hay, Ken Haggard and Phil Niles full scale Skytherm house 1973 Sliding insulation panel system not well developed

Improved roof pond system Jon Hammond redesign uses hydraulic rams Lids up on cool summer nights and closed in the day Lids down on winter nights and up on sunny winter days

More cooling for hot climates 1970s - The Environmental Research Lab in Tucson Research on the excellent performance of downdraft evaporative cooling towers

Evaporation and radiant sky cooling -- the Cool Pool A shaded evaporating roof pond can maintain comfort under extreme conditions Radiation to the cool sky adds to evaporation Performed very well in a hot parking lot at the California State Fair

Un-integrated design Solar brutal - too many windows, not enough insulation, thermal mass, or solar control Can be too hot in any season--but still cold on dark winter days Common in 1970s New Mexico but this example is from Oregon Still done today - poor orientation can be disastrous South windows should Be 10-20% of floor area, rarely more

Estimated costs Clothesline 0.002 cents per kwh Passive design DHCV Passive water heater 1-2 cents per kwh Active water heater 2-7 cents per kwh Photovoltaic 10-30 cents per kwh

Daylighting 5.0 Daylighting reduces cooling loads Improves people’s attitude and health Saves energy Often the key factor in commercial buildings

Easy to model Light shelves on south facing walls are very effective for daylighting They control glare and bounce light further in Models allow quick checks of lighting

Daylighting Orientation (12 ft) Taller ceiling (16 ft) Light shelf (25 ft) Angled ceiling (28 ft) Optimized (39 ft) Use physical and/or computer model

Community design 5.0 Mike and Judy Corbett start a remarkable solar development with passive solar heating and cooling More than 200 units, designed for bikes, walking and community building 50% less energy used than adjacent developments (1975) Mixed use A delightful place

The challenge in 1980 We knew how to do very high performance buildings With super-insulation and effective thermal mass (water best) How could we build super-insulated buildings with high internal mass at competitive cost?

The answer emerges DB, Matts Myhrman, Bill Steen A consulting job for a pig farmer in 1983 led me to straw bale building Historic straw bale buildings in Nebraska, Wyoming and Alabama In 1989 the first straw bale workshop was held near Oracle, AZ DB, Matts Myhrman, Bill Steen

1994 The Straw Bale House Straw bales provides high insulation value and significant amounts of plaster for distributed thermal mass Just five years later we published the first big book on straw bale construction Sale have now passed 125,000 There are more than 20 sb books in many languages

Straw bale passive solar homes Near Bishop, by Ken Haggard and Pliny Fisk Probably the first permitted straw bale in California With composting toilets, greywater biobeds Higher performance--modest price

Integrated commercial design 6.0 Daylighting Passive heating, cooling, ventilation General Services would not accept a floating temperature in our 240,000 square foot building in 1975 Even after we showed it would be better than existing buildings nearby 88% energy savings predicted Jon Hammond, David Bainbridge, Loren Neubauer, Jim Plumb, Marshall Hunt, Denny Long, Living Systems

Office space 1976 Ken Haggard and SLOSG submitted a roof pond design the next year It would have provided 100% heating and cooling The design was not “hierarchical” enough

Office space Ken Haggard, Polly Cooper and their staff have designed more than 200 passive solar buildings since 1975 This is their passive solar, straw bale off-grid office Daylit, natural ventilation Waterwall for heating and cooling

Assembly building/offices Daylit, naturally heated, cooled ventilated synagogue Energy use 82% below California’s energy code Water walls for thermal mass Straw bale walls Ken Haggard and Polly Cooper San Luis Obispo Sustainability Group, 2006

Police station Daylit, light shelves Passive solar Police station Visalia Jon Hammond, Indigo Architecture, 2006

Passive Solar Europe Germany and Scandinavia began passive solar home building in the 1990s Good resources and support Typical 70-90% savings Driven by true cost pricing 30¢ kwh PassivHaus Institute

Big office buildings! ING (NMB) bank building in Amsterdam, 550,000 sqft by Ton Albert (1987) Daylit, natural ventilation Passive and active solar 90% energy use reduction no increase in cost Reduced absenteeism Overcrowding led to changes in systems - mechanical added Operable windows did experience some noise issues

Mixed use passive The Prisma building in Nuremberg Design Dr. W. Stahl, SUNNA Daylit, passive heating, cooling and ventilation 140,000 square feet

The global challenge Simple passive solar straw bale homes ADRA Simple passive solar straw bale homes Thousands underway in China thanks to Kelly Lerner and other volunteers, ADRA In Mongolia energy use was cut 80%

Passive solar obstacles An anti-solar building--we could hardly do worse Perverse incentives--almost everyone involved has incentives to do the wrong thing Key issues - subsidies, developer v/s client, tax code Result: sealed, unhealthy, unsustainable buildings Estimated lost productivity and medical costs $200 billion a year (Dept of Energy)

What should we expect? Health, comfort, joy and beauty! 90% less energy needed for heating and cooling 90% daylighting Natural ventilation with operable windows for most buildings < 6 stories Comparable first cost More sustainable materials