This passive solar air heater is mounted on the side of a building.

Using the naturally occurring laws of physics, a passive solar hot air heater uses the heat from the winter sun to heat indoor living spaces.

Because the sun follows a similar, predictable pattern throughout the seasons, if the solar heater is positioned in a certain place in a certain way, it will not receive any summer sun.

This type of heater is also referred to as a thermo-siphon solar air heater.

I’ve seen these types of solar heaters on barns and houses, but this particular heater was totally passive solar.  (Cool!)

This means that it works without electricity, simply by being in its location (on the south side) and by how it is built.

While this article is being posted in the summer, keep in mind that this project would take only a day or two to build, and summertime – when it’s warm, is the ideal time to build this type of project.  (This particular one involves knocking holes into your walls.)

This passive solar air heater is on the south side of the ReStore in Silver City, NM.

I participated in a passive solar heater workshop on a on a cool, spring afternoon in Silver City, New Mexico.

The solar heater was built from easily obtained materials and was mounted on the side of a Habitat for Humanity ReStore.  (The heater can be seen just under and to the left of the ReStore sign.)  Since the office was located on the south side of the building, it was a perfect position to build a passive solar air heater.

 How a Solar Air Heater Works

A current of hot air can be felt. At 103 degrees, it was a surprisingly strong current of air.

Upon entering the office to view the solar air heater, I noticed that the room was noticeably warmer.  This was a good thing, as I visited on a cooler spring day.  While the outside temperature was about 68 degrees Fahrenheit, the air blowing into the space was 103 degrees Fahrenheit.

There were two holes located at the top of the heater, and two at the bottom.

The passive solar design creates a natural vacuum that allows cool air to be sucked into the lower section of the solar heater where it immediately starts to warm.

Within the heater, there are two pieces of darker aluminum screens sandwiched in the middle that help to warm the passing air.

Since hot air rises, it continues to be heated until the top is reached, where it travels into the room.

This natural cycle allows the air to circulate and transfers the solar heated air into the conditioned space.

When sun goes down and the outside temperature starts to drop, there is a built-in function that stops the airflow into the room.

When the temperature outside the building drops below the building’s inner temperature, the parchment paper located at the top of the screen is sucked against the screen and stops the cycle of airflow, keeping the cooler night air from cycling into the building. (Although this heater was not insulated, so cooler air would inevitably enter the space during the night.)

What Basic Materials are Needed

The tempered glass was sealed in place with caulk and a piece of wood.

The passive solar heater was built out of glass panels that were formerly used as shower walls.

The other materials were 2×4 and 2×6 pieces of wood, aluminum screen, nails, caulk and parchment paper.

This is a good project to try on a barn or garage, but could also be integrated into a main living area.

It can be built in a day and serves as another way to warm a space naturally with the sun.

If is it mounted on a south facing wall, it will warm the space in the winter, yet with the sun ‘traveling’ a higher and wider path in the summer, with a proper overhang, the heater will not receive any sun, hence heat, in the summer.

Here’s another way of building a solar air heater.

Diagram of a solar window heater.

I found this diagram after doing a basic search.  I’d recommend researching this method before building it. According to the diagram, it looks like cooler air is (in theory) enters from the top.  It would make more sense to have cooler air enter from the bottom, however, if that’s the case, according to this design, then the cooler air would be coming from outside.  Winter air would be much cooler, thus having a great temperature differential that would cut down on its overall efficiency.

Also keep in mind that this will make whatever materials are utilized in its construction, very hot. When building and updating building, remember the mantra: Do no harm.

I recommend using tempered glass for building passive solar air heaters, since polycarbonate and other oil based transparent materials will off-gas as they get hotter. One doesn’t want to poison oneself while trying to warm the house.

Here’s a somewhat long-winded, yet informative video that looks at a large passive solar air heater installation.  The info starts at 0:54.

I’ve also seen these types of solar air heaters built with aluminum cans.

Thank you to the ReStore and to Asher Gelbart for giving the workshop.

A solar air heater would be a great summer project.   Have fun and remember that it’s better to build these when the weather is warmer.

This was originally posted at The Crestone Eagle, by Kelly Hart

A passive solar cold frame growing box

Last spring I built a simple cold frame to get an early start on plants to set out into the main garden later, and also as a place to keep some plants that particularly love warmer weather. It worked very well for these purposes, providing tomatoes, cucumbers, cauliflower, squashes, peppers, eggplants and many other veggies in abundance.

Then this last Winter Solstice we decided to experiment with planting in the cold frame again, just to see if was possible to use it in the winter for growing food. As a sort of control, we also planted seeds in the adjacent greenhouse at the same time. We chose mostly cool season plants, such as lettuce, arugula, peas, bok choy, kale, radishes, etc. that we knew could take a light frost.

It turned out to be particularly cold weather, with several weeks when it never got above freezing outside and with many nights in the minus teens and down to minus thirty here in Casita Park where we live. This, combined with the shortest days of the year, made for harsh growing conditions to say the least.

The seeds were understandably slow to germinate, but nearly all of them did eventually push their tender little feelers into the crisp air. Now, less than two months later, we are eating salad greens daily and will be getting peas soon.

The surprising thing to me is that the cold frame is actually out-performing the greenhouse . . . and this is with a hot tub kept above 100° most of the time in the greenhouse! Why would this be? I’ll tell you the secret: basic passive solar design.

As you might be able to tell from the accompanying photos, the cold frame has a wall of large stones stacked against the north side, which is also the insulated foundation wall for the greenhouse. These stones absorb heat from the sun all day long (even on overcast days) and hold the heat, gently releasing it throughout the night.

Another unseen trick to the design is that I buried about two feet of 1 1/2” rigid insulation in the ground around the perimeter of the cold frame. This effectively isolates the frozen ground outside the cold frame from cooling the soil inside. Even when the air temperature inside the frame might go below freezing, I don’t think the soil did. At night, I also place insulation panels on top of the cold frame to help keep it toastier in there.

My cold frame is roughly 16 feet long, 3 feet wide and 2 feet high in the back, tapering to 18 inches in the front. The top is made of two lids that are hinged in the back so they can be lifted and secured up against the greenhouse wall if necessary, or propped open to ventilate the space. Depending on what you might want to grow in such a cold frame, it could be built higher to accommodate larger plants. During the summer when I had peppers and eggplants growing in the cold frame, I just left the lid open all of the time, so the plants grew beyond the height limits. The total cost of the materials for this was about $250, mostly for the 3/8” twin wall polycarbonate glazing, which I picked up at SLV Building Components in Alamosa.

Here’s another example of a cold frame from Wikipedia.

Ordinarily, I wouldn’t advise that people plant seeds in the dead of winter; had I planted earlier, I would have been enjoying salad greens much sooner. What is exciting to me about this experiment with my cold frame is that it proves that it is possible to grow food in our climate year round, without any heat other than that provided by the sun.

I installed a wireless thermometer gauge inside the cold frame that has a readout on my desk, where I monitor the temperature frequently. If it rises close to 100°F. I will go out and prop open the top of the cold frame to allow ventilation to keep from cooking the veggies. I enjoying keeping track of this, and it is easy since I am home most of the time. But if circumstances were different, I could install a simple thermostatically controlled ventilation system to keep the cold frame from overheating.

On a frosty day when I opened the lid of the cold frame to water or harvest veggies, the steamy interior air would spill over the sides. That wonderful warm, humid environment is perfect for the little plants. They are happy . . . and that makes me happy!

The original article: http://www.crestoneeagle.com/a-passive-solar-cold-frame
This is a simple cold frame that can easily be built.  It uses elements of passive solar building such as south-facing design, thermal mass and insulation.  It was inexpensive to build and made it possible to enjoy fresh vegetables in the early spring.

The desert city of Arcosanti faces the south and is etched into the hillside.  Arcosanti is located outside of Cordes Junction, in Arizona.

Paolo Soleri is an architectural visionary, seeking to solve the problems associated with urban sprawl and its resulting social decay. He saw that society had become more isolated from the natural world and proposed numerous solutions to design the community back into the core of the city, while using less resources, increasing efficiency and utilizing open space to nurture an appreciation of one’s surrounding natural habitat.

The Visitor’s Center from the south as it faces the canyon.

I arrived to Arcosanti early in the morning, and as the Visitor’s Center had not yet opened, I took a walk down a dirt road.  Not knowing where it led, as I rounded a corner, I was faced with a massive 5 story building accompanied by the sound of bells chiming in the wind.

I felt small as I walked toward a futuristic fortress-looking building with its large glass windows looking down on me.

Arcosanti is a city prototype that will one day sustain and house up to 5,000 people.  While the living areas and cities are quite compact, it borders a 3,200 acre preserve.

The cafeteria is filled with light and has a gorgeous view out the large windows.

The five story building that houses the Visitor’s Center, bakery, cafe and offices is an exquisite blend of the contrasting terms of mass and tremendous weight to with light filled spaces that nurture and a sense of weightlessness.

This concrete building style is typical of all the buildings throughout the city.

A fan located at the top of the orange heat sleeve transfers the warm air that collects at the top of the building into the space below.

The Visitor’s Center is also a passive solar building and does not have an external heating or cooling source.

Notice how the sunlight enters through the large southern facing window.  The sun’s heat is absorbed into the tile floor, a material with thermal mass that slowly radiates the heat back into the space.

The orange sleeve that can be seen on the left hand side of the picture pushes warm air collected at the top of the building into the space below.

Paolo Soleri’s bells chime to welcome to the visitor.

Paolo Soleri is renaissance ideal, being a prolific writer, designer, architect and artist.

He has penned numerous books, designed and built bridges, amphitheaters and buildings, and started the Cosanti Foundation. His bronze and ceramic bells are made at Arcosanti.  Soleri’s Cosanti property, located  in Paradise Valley, Arizona, also makes bronze bells. The sales of these bells help to support the building efforts at Arcosanti.

Passive Solar elements design allows the winter sun to warm a work area.

The bells are made in the foundry, an area shielded by a half dome that creates a configuration that allows work to take place in the open air.

The foundry also feature passive solar elements.  Because it is located in the high desert of Arizona, it can get mighty hot in the summertime.  Because the entire city faces the house, Soleri designed Arcosanti to take advantage of this.

This picture was taken in January, close to the winter solstice.  In the cooler winter months, the winter sun warms the area and its heat is absorbed into the thermal mass of the concrete.

In the summertime, the high winter sun does not enter into the domed area and the foundry is shaded and keeps the working area cooler.

White lines painted on the floor under the domes mark where the sun enters at certain times of the year.

Passive solar building relies on basic scientific principals that have been used throughout time.  Notable historical examples are evidenced by the Anasazi Cliff Dwellers and the ancient Greeks.

Soleri designed the city to have areas of public, shared community space along with with private living areas.

A public, shared space can be seen under two large concrete domes.

There are also a couple of chairs and children’s toys in this area.  White lines have been painted on the floor under the domes that is indicative of how far the sun enters the domes on the the winter and summer solstice as well as on spring and fall equinoxes.

Paolo Soleri believes in the integration of passive and active solar elements to make sustainable cities.

Soleri believes in the combination of both passive and active solar elements create the ideal urban environment.  These principals can be seen in action throughout Arcosanti.

The combination of passive and active solar building elements creates a community that uses only about 1/5th of the energy that a traditionally built development uses.  (I am told that this amount varies throughout the year.)

All of the active solar photovoltaic panels incorporated into the build supply about 10 percent of the energy that the community uses.

Public and private spaces were intermingled throughout the development.

The intermingling of public and private areas can be seen in the amphitheater.  People in the community have their own private living areas, while having opportunities to actively engage with the community.

The amphitheater is a half circle around the stage, while apartment buildings surround the amphitheater.

This type of community contrasts with the notion of suburbia and neighborhoods of residential areas where people must travel outside of the neighborhood to grocery stores, restaurants and entertainment.

A water faucet is tucked away under the seating to provide water for the plants.

There are many different resource saving elements built in throughout Arcosanti.  Water from the roof is channeled into and collected in a cistern.  That water is accessed by a water faucet that can be seen close to the sidewalk, under the seating area.  (Look at the brown strip in the lower 1/5 of the picture and see the faucet located just above it in the middle.) A water hose is attached to utilize the water for the plants and trees.

I continued to explore and came upon a trail marked as a “Visitor’s Trail” that led into the canyon.

I walked to an overlook across from Arcosanti and was faced with a futuristic city, composed of many buildings and areas. Sounds of workers and music from the radio wafted toward me and mixed with the sounds of small animals scurrying and birds fluttering to different bushes.

There is work being done on the lower section of Arcosanti on guest housing.

Construction on Arcosanti started in the 1970s and continues today. Work is currently being done in front of the guest housing on a large terraced greenhouse.

An artist rendering of Paolo Soleri, by Simtropolitan, contributor to Wikipedia.

Mr. Soleri envisioned and drafted the plans for many different types of large, sustainable cities that could support thousands of residents.  He designed all his cities to incorporate the good aspects of the city, (good food, community leisure and entertainment) while preserving the tranquility and importance of private spaces with the goal of living more efficiently and sustainably. He is a creative visionary.

“His philosophical and environmental perceptions offer a sudden,  stunning pertinence for today. He does not need the current bandwagon  of despair. He has been preaching environment and ecology for a long time … He has been the prophet in the desert and we have not been listening.”

—Ada Louise Huxtable, The New York Times, 1970

Currently, there are mixed use, urban developments are going in the direction of mixed use environment, such as TAXI, outside of Denver, but not to the extent of sustainability that Paolo Soleri envisions.

There is also one major sustainable solar city development that is being built in the UAE called Masdar, to be completed in 2025.

Arcosanti is located at exit 262, Cordes Junction on I-17, in Arizona.

Arcosanti is a beautiful urban development with sustainability, modern design and community at its core.  We need to have more of these types of developments.

There is active industry there with the building of bells within on-site foundries, making both clay and bronze bells.  When I visited, there were about 60 residents living there in the winter.

While Arcosanti is located a short distance from the Interstate, it imbues a different, futuristic, progressive feel, making the interstate feel as through it was a relic from an older era.

Arcosanti is open to the public and offers tours, retreats, workshops and summer concerts.  You can also reserve a room at Arcosanti and enjoy baked delights and food in the cafeteria.

It’s a great place to visit, find inspiration and be thankful for the good people in the world.

Paolo Soleri recently passed away at the age of 93.  He leaves a legacy of beauty within his many creations.

Visit the Arcosanti website: Arcosanti.org

This house has a lot of solar goodness going on.  The additions were built in stages to incorporate both passive and active solar elements.

The original home is situated in the middle of the current house, sandwiched by the first addition to the south, followed by the two story addition built onto the northern side of the house (south facing).

The Sun Room

The southern facing sun room was the first addition to the home.

The first addition the adobe home was the stick-frame sun room built to the south of the home.  The early addition has both vertical as well as slanted, overhead glazing.

It was built on a 4″ concrete slab floor that is its thermal mass.  Prior to pouring it, they mixed in a pigment to give the floor a reddish hue.

The windows (glazing) are homemade double paned glass panels.

After building it, they found that the overhead glazing made the house too hot during the Albuquerque summer time.

As a result, they took out the overhead glazing on the western side.  (Additional hotos can be seen in the gallery below.)

A hinged window can be opened to vent the sun room.

Venting windows were installed in the upper west and east facing walls of the sun room.

When open in the summertime, they allow ventilation into the space while allowing hot air to leave the room.

In addition to warming the house in the winter, the passive solar additions also allow more light into the adobe home.

Inside the Main House

The original older adobe house was built in the traditional pueblo New Mexico style, with a flat roof and vigas, the logs supporting the roof.

They were traditionally built with thick adobe walls and small windows, attributes that can lend to a darker house.  In addition to the sun room, overhead sky lights were also installed over the entry way and the kitchen.

There is only one propane backup source of heat located in the dining room.  The owner says that it is typically only used on winter mornings.

The Northern Addition, Trombe Wall and Water Tubes!

The two story addition has a Trombe wall built on the eastern side of  south facing window wall.

In the second stage of building, a two story addition was built to the north.

The passive solar addition is wider and taller than the original house, so the sun can passively warm the south-facing, northern section of the building in the winter.

On the eastern side of the building, a two story adobe Trombe wall is used.  The Trombe wall is warmed by the sun throughout the day and then releases its stored heat into the house throughout the cooler evening and night.

On the western side of the building, the southern facing windows allow the winter sun to hit a water wall located within fiberglass tubes inside the house.

Because the house faces the south, an overhang is used to block the summer sun thus keeping it cool in the hotter summer months.

The adobe bricks used in the Trombe wall were purchased from an adobe brick company NM Earth.

When asked about the process of building with adobe, and the builder echoed what people who build with adobe typically say, that it is a relatively forgiving, nontechnical material, and that adobe can simply be stacked up within a framed structure.

When approaching the home, the second story gracefully exudes its artistic dominance over the older adobe.

This is the inside of the two-story Trombe Wall showing the section near the roof.

Going inside the house to see the other side of the Trombe wall, an open lavender room greets the visitor.

In order to keep it from getting too bright,  they used glass bricks and a east facing bay window in the room.

They kept a similar south western look throughout the house by building the same viga-style ceiling.

Here another house that has a Trombe Wall.

The layers of the house from inside to outside are: adobe, a vapor barrier of tar paper and wire mesh, followed by 2 inches of urethane foam insulation. (Because passive solar houses store and then release the sun’s heat through the colder winter night, the outer walls must be insulated.)  This is followed by a layer of adobe plaster to the outside.

Water Tubes for Thermal Mass / Temperature Moderation

The fiberglass water tubes allow the home to store the sun’s heat in the tubes.

On the western side of the two story addition located behind the existing house, huge fiber glass tubes filled with water are situated to collect and store the sun’s heat in the winter.

In regard to thermal mass, water has the ability to absorb and store the highest amount of  heat, over twice that concrete or stone.

The owner said that they were installed in the house over 12 years ago and are very low maintenance.  He pours a little bleach in them about once a year to keep the water clean and free of algae.  They have had the same city tap water since they were first brought into the house.

This is the view looking up into the rafters of the house. The southern facing glazing is on the left, and the fiberglass water tubes are on the right side of the picture.

Here’s a view of the windows that face the south within the two story addition.

Because of the orientation of the windows (facing the south) combined with the overhang on the roof and the positioning of the glass tubes, the house does not receive that much direct sunlight in the summertime, helping the house to stay cool.

In the winter, because the sun travels a lower and shallower path, the winter sun hits the tubes of water on a sunny day allowing the water (thermal mass) in the tubes to absorb the sun’s heat, helping to keep the building warm.

The tubes of water are a great way to add thermal mass to a building.  As stated previously, water is a more efficient heat storage medium than concrete or masonry.  For example, a cubic foot of water can store 62.4 BTU’s for each 1 degree Fahrenheit rise in temperature, while a similar volume of concrete can store only 28 BTU’s for each 1 degree F temperature rise.

BTU (British Thermal Unit) is a unit of measurement that quantifies heat.  One BTU is the approximate amount of heat required to raise one pound of water by one degree F.

Active Solar

There are three rows of 15 panels on the roof of the adobe house that have already paid for their existence – and continue to pay to the owners for the solar energy that is generated.

The last modification to the house was the integration of active solar on the roof to supply solar electric power.

The active solar system was added in 2005 shortly after the first Gulf War, for practical and philosophical reasons.

It was one of the first grid-tied active solar home systems added in the state of New Mexico.

Debunking the false myth that solar doesn’t pay for itself, the system cost the owner-builder $30,000 and was paid for in the 8th year.  The array is composed of three sets of 15 panels and is rated at 5KW.

Because the home is grid tied and creates more energy than the home uses, the solar system continues to generate money.  As a result, the household receives a monthly check from the electric company that varies between 80 – 90 dollars.

Even on a cloudy day, the solar system was producing electricity.

In New Mexico, the utility company pays the retail price for electricity generated and put into the system over and beyond what the building uses.  (This is in contrast to Colorado, where utilities pay the wholesale price for energy generated by external solar electric homes and businesses.)

I visited the house on a cold, slightly overcast day in December.  Notice that even on a cloudy day, the solar photovoltaic (PV) system was creating electricity.

A passive solar sun room was added to the front of the house.

Looking at the addition from the southwest, one can see where the sun room joins the adobe.

There is also a cistern that collects water from the roof.  The tank is slightly raised, so when a hose it attached, via gravity, it is fed into the hose and to the garden.

This house has shown innovative ways to add passive solar additions to a house.  The inside of the home was filled with light and warm, even on an overcast day.  While the different additions were added over many years, the result is a comfortable, modern and efficient home.

To see more photos of the house, take a look at the photo gallery below.

Photo Gallery

Click on a picture below to enter a slideshow of the photo gallery.  Use the arrows to navigate or click on the right hand side of the photo to progress to the next one.

The house is approximately 3000 square feet.

It’s a bitterly cold day outside. The outside temperature is around 0°F, 20-30 mph winds, wind chill close to -30°F and I couldn’t feel toastier! Oh how I love the passive solar effect! Sunshine streaming in through the windows, a concrete floor soaking up the radiant heat, and thermostats in the 75-81°F range without a bit of help from our furnace.

To give you a little better idea what’s going on, how about a few pictures:

Family Room Windows – A beautiful, sunny, blistery winter day – 0°F with 20-30 mph winds

The winter sun is always low in the sky.

Beautiful Sunny Winter Day – Low Sun Angle on 1/2/2013

At this time of the year, when we need heat the most, it’s very close to the winter solstice and the sun is at its lowest angle it will be for the entire year.

Family Room Windows – Lookout Deep the Sun Radiates into the Space

Notice how deep into the room the sun’s rays strike, radiating onto the dark tile, heating the concrete underneath as it absorbs hundreds of thousands of BTUs from the sun. This energy will go into the concrete floor instead of overheating the house and gradually reradiate into the house later this evening.

The really awesome thing about passive solar heat is it works best when you need it the most! Say in the middle of the winter when it’s cold, especially on these bitterly cold subzero days. Don’t know if you ever taken a moment to step back, and really think about these supercold days, but any time it’s freezing out, like below zero, it’s always sunny. You see, air can only hold so much precipitation depending on its temperature, and the colder it gets the less it can hold, so any time it’s really cold that means it’ll be bluebird sunshine outside! Great thing because this means any time in the winter when we really need heat the most we get it for free!

Contrast this to the middle of the summer when it’s hot outside, the days are long, and the sun is high overhead, and the sun’s rays aren’t creeping into the house even a bit. Yes, it’s still bright/sunshiny inside, but no direct impact from the sun’s rays keep things from overheating. Even more, you can reverse the heat storage effects of the concrete in the summer by opening the windows at night to cool down the slab, and then closing the windows during the day to use the cooled slab to keep everything comfy. Considerable free heat in the winter, some cooling in the summer… Can somebody please tell me why more people don’t build their homes this way?

Really, it’s that amazing! I read about passive solar, researched it, incorporated it into my house design and WOW… what a difference! You really have to feel/experience it to completely appreciate the difference, and let me tell you, anyone who steps inside my house on a freezing cold day will instantly feel the sunny warmth and know what coziness is all about. Ahh… I love the sun!

Even Caleb enjoys it!

Caleb relaxes in the sun.

Take a look at his website, as it is a really a great read. Quadomated.com

About the author:

I’m just one happy geeky quadriplegic engineer living life to its fullest! With the majority of my body paralyzed and a very upbeat attitude I have a unique perspective on technology, living life, building homes and everything in between.

He built a lovely passive solar house and documented the build: Quadomated.com/category/house

All the competition homes are on display to the public during the Solar Decathlon.

Innovation from fresh minds is encouraged and spurred when colleges and universities compete in the most challenging solar home design competition in the world, the Solar Decathlon.   Spanning over two years of work, architecture and engineering schools pooled their best and brightest to build efficient solar houses.

Here’s a subjective “Best of” from the 2011 Solar Decathlon.  The photo and name link to the article, while other links go to a specific section in the article.

Best Passive Solar

Victoria University of Wellington, New Zealand | First Light

• Classy integration of passive solar thermal mass, best tucked away sleeping areas, and passive cooling in a lovely house endowed with a dose of zen.
• Best to home put on a beach
• Cool and noteworthy: A solar hydronic drying cabinet (nice for swimsuits – and other clothes)
• 1st Place in the Engineering category

Middlebury College, Vermont | Self Reliance

• Great combination of southern facing glazing with thermal mass
• Ingenious planting wall with solar control.
• Coolest Passive Solar – Grow space

Appalachian State University, North Carolina | Solar Homestead

• Cool Trombe wall – window modification
• Best outside living area
• The Solar Homestead won the People’s Choice Award – They also did a great job marketing as their team handed out pamphlets that doubled as a shiny, reflective hats.  To my amusement and mild annoyance, because people wore them, the shiny hat kept getting in the photos of the other houses.

Team Tidewater | Unit 6
Old Dominion University and Hampton University

• Best Passive solar porch
• Phase change material under tiles to bulk up the thermal mass in the porch
• Passive cooling with air currents

Team New Jersey | EnJoy
Rutgers, the State University of New Jersey and the New Jersey Institute of Technology

• Best, massive use of thermal mass within passive solar design
• House that could be in a museum of modern art

Team Massachusetts | 4D Home
The Massachusetts College of Art and Design and the University of Massachusetts at Lowell

• Best student designed furniture: A cork, titanium chair caught my eye.
• Coolest Solar blocking – overhang
• The 4D Home also had sliding walls and placed 2nd in the Energy Balance category

 Best Ingenious Design

Team California | Chip
Southern California Institute of Architecture and the California Institute of Technology

• Coolest High Tech House, with motion detection to save energy, house with an app
• Cool student designed furniture
• Team that seemed to be having the most fun (ie. great teamwork)

Best Zen House

University of Maryland | Watershed

• Best symbiotic relationship with nature – house
• Best shower
• Overall Winner of the 2011 Solar Decathlon

Best Passive Cooling

Team Tidewater, Purdue, Team Cali, Team New Jersey, and the Univ. of Wellington

Best Protected in a Hurricane

Florida International University | PerFORM[D]ance House

• Best house with a view
• Most poetic

Super Cool Things Listing

- Cool Windows

• University of Tennessee – Air flow and shades within the window
• Team Tidewater – Duel opening

- Cool ‘Biowall’

• Purdue - A biowall is a plant air filtration system set into the wall.  They also had shades that alternated a solid and translucent material that allowed more or less light into the room

- Cool Room Dividers, Moveable Walls

• China, Massachusetts, Old Dominion / Hampton – All had moveable partitions or walls within the house.

- House with a desiccant system

• Team Florida, Maryland

- Control House with an App

• Cali, Purdue, New Zealand, Tennessee

- Most Surprised By

• China – Who would have thought that living in shipping containers could be so nice?

Notable

• City College of NY, Solar Roof Pod – Dwelling designed for rooftops
• Parson NS Stephens, Empowerhouse  – Building for Community, Efficiency
• University of Calgary – TRTL – Building for the Rez, Permafrost

Other Participants in the 2011 Solar Decathlon

• Ohio State
• Illinois at Urbana
• Ghent University

Everyone gathered in the big tent to hear the section winners during the Solar Decathlon.

This ‘Best of’ was based off my experience at the 2011 Solar Decathlon.  Some university teams gave great tours, thus making knowledge and information available.

There is another Solar Decathlon coming up in 2013.  Attend to get inspiration and join in the fun!

SolarDecathlon.gov

The City University of New York created a home that could be situated on the roof of a building.

The roof mounted solar photovoltaic (PV) panels supply the house with energy while it also shades the structure to keep it cool in the summer.  In addition, each solar panel was fitted with a micro-inverter to maximize solar energy output.

The bathroom in the Solar Roof Pod. Photo credit – DOE Solar Decathlon, Jim Tetro

One enters the inner sanctum of the Solar Roof Pod via a ramp while passing a rooftop garden.

There were two main entrances to the home that were situated on opposite sides of the structure.  The tour entered the home through the north entrance.

Immediately upon entry, one could easily access a bathroom just across the entryway.

The close proximity of the washroom is a nice asset to have in any home.

Note the efficient stacking washer and dryer in the bathroom. Because there is an inner core within the house, the water lines are kept away from the colder edges of the house and kept in close proximity.  This makes building the house more efficient.

The traffic-flow took place around the core of the home.

Continuing around the corner from the restroom, one continues to the bedroom and sleeping area.

The Murphy-style bed can be hidden in the wall on the west side of the house.

There was a Murphy – style bed that descended out of the wall.

In the panoramic picture above, there are two people on the left -hand side by one of the main entrances, adjacent to the bathroom doorway.  In the middle of the picture, the Murphy-style bed is being placed in the wall, and to the right of the picture on the west facing outer wall, a solar energy collector can be seen.  It allows light into the living area, while it also collects solar energy from the setting sun.

Sliding doors, often referred to as ‘pocket doors’ do not take as much space as a swinging hinged door, yet provide privacy.

Continuing around the corner, one finds a kitchen and deck area that faces the south.  (See pictures of the kitchen in the photo gallery below.)

Note the sumptuous wood paneling on the walls.  I am pretty sure that the team built the walls along with all other facets of the house.

I visited the team in the middle of the summer just prior to the 2011 Solar Decathlon and was impressed by the engineering and architecture teams that were working together and building many of the different aspects of the house.  See the insulated walls being built.

The living room space was airy and inviting. Photo credit – DOE Solar Decathlon, Jim Tetro

Continuing past the kitchen area, one enters the living room area.  It was the largest space in the home with ample areas to sit back, relax and enjoy the view.

The Solar Roof Pod would ideally grace the rooftops of large cities, extending the building’s potential living area.

Because the Solar Roof Pod was destined to be situated on a roof, the building was set upon I-beams and surrounded by a deck, complete with a system to recycle to water for the garden surrounding the building.

As mentioned earlier, this was a project that I had the opportunity to visit during the preceding summer. It was impressive to see how much work the teams accomplish over the summer.

I realize that it’s also easy to overlook the massive amounts of work that can not be easily seen when touring homes during the Solar Decathlon.

Because I saw part of the building process, with the panels lined up in a warehouse, I knew that the panels of the house were all hand made, even down to the insulation that was blown into them. This extra effort, however, is not recognized in the Solar Decathlon within the points system.  In my opinion, it should be recognized.

Other schools participating in the Solar Decathlon contracted out various aspects of the building process to other companies, some to the extent that main aspects of the house were not built or experienced by the students. No doubt that student teams learned regardless of the process that was used, however, the point being that some schools expended more effort than other teams did.

This team worked hard to create a symbiotic house destined to utilize the rooftops of city buildings.  It was a brilliant idea that should be recognized and mass-marketed.

Take a look a the photo gallery and the video below to learn more about the Solar Roof Pod.

Photo Gallery

Click on a picture to enter the gallery.  Click on the right side of the picture to proceed to the next one.  Click anywhere in the darkened space or on the “X” to exit the gallery.

It was a noble effort with thousands of hours of work from the Solar Roof Pod team.  The team learned a lot while finishing in 17th place overall.

The scores for the City College of New York team for the 2011 Solar Decathlon.

Shortly after the 2011 Solar Decathlon, it was announced that the City College Architecture Center would be closing.  It appears that it has become the J. Max Bond Center.

See the original model of the Solar Roof Pod entered into the 2011 Solar Decathlon.

Preparation for the Solar Decathlon during the prior summer.

The website for the Solar Roof Pod: Ccnysolardecathlon.com – It appears to have been hacked at the time of this writing, so this is not linked.

Solar Decathlon Main Website: solardecathlon.gov

The Quonset hut addition was warm and filled with light.

It was rejuvenating to visit and experience a beautiful house as well as be in the company of people who take pride in what they build and where they live.

A gleaming Quonset hut graced the top of the hill that was at one time the mission and village square that was the bustling center of Galisteo.

The Quonset hut addition was attached to the the older adobe house. The kitchen sits to the left hand side of the picture.

In this home renovation, a translucent Quonset hut was added to a centuries old adobe house.

The addition fills with light during the day, while it becomes a glowing orb on the hill at night.

I visited on a cool November day when clouds alternated with strong sun. Upon entering the house, an immediate sense of both warmth and light enveloped me. Certain homes simply feel good. This space emanated warmth and light.

A Rumford fireplace, designed to emit a maximum amount of heat, graced the corner of the home.

The Rumford fireplace next to the entrance created an abundance of heat merely by its design.  (Yeay!  Efficient by design = passive – because it just sits there or does what it does, efficiently.)

The sides of the fireplace have a 43 degree angle that reflects the fire’s heat into the living area. (Badly engineered fireplaces and stoves do exist.  I once lived in a place that had a ‘cold fireplace’. It needed have a roaring fire that burned in the stove for about an hour before it started to warm the living area.)

The Rumford fireplace was originally engineered by Sir Benjamin Thompson, Count Rumford, who studied heat radiance in the late 1790s. He advocated smaller and shallower fireplaces that were curved to allow them to both radiate heat into the living area and allow the smoke to easily escape.

In addition, the stove is built into a wall of thermal mass.  It kicks out serious heat.  Additional pictures of the Rumford stove can be seen in the gallery below.

The winter sun strikes the north wall of the house to warm its thermal mass.

The Quonset hut was built to the north of the original adobe structure.

Initially, my passive solar schooling resisted the idea of building anything with glazing to the north, yet for sunny, hot New Mexico, it makes perfect sense.

Because the Quonset hut is located on the north side of the house, it won’t get as hot as it could in the summer. Although it does get plenty hot, up to 175 degrees Fahrenheit. Because of this, they are looking into types of covering for the summer.

There is an exhaust fan located near the top of the wall that can be opened to allow heat to escape.  (See the gallery below.)

In the winter, however, the space is warm and filled with light. The passive solar aspect of the house is fulfilled as the winter sun strikes, warms, and is absorbed into the (southern facing) north adobe wall of the house.

They used pressed adobe bricks that were mortared with adobe plaster.  They left part of the adobe wall rough and contrasted it with a smooth, white plaster.

A white diamond plaster finish reflects the light in the Quonset hut.

The home stayed true to its New Mexico adobe architectural roots with its thick, curved walls. The smooth ‘white diamond’ plaster finish reflected the light nicely.

As I gawked at the house and listened to David and Eric, it dawned on me that they have a type of wealth and ease that most people dream of.

They designed and built a house that meets their desires and needs.  It is a comfortable space that allows them to pursue art and leisure.

The Kitchen

Eric made some breakfast while enjoying the view.

A kitchen was built to the south of the Quonset hut.

The kitchen windows allow for a 180 degree view of the valley below.

The kitchen was designed with utility, practicality and beauty in mind.

The dishes are washed and placed into the drying rack above the sink. That is also where the dishes are stored, thus, they don’t need to be moved after they are dry.

Overall efficiency was built into the house.  It’s one of the luxuries that owner-designer-builders have.

The kitchen with an ingenious dish drying / storage rack.

A large portion of the items used in the retrofit build came from reclaimed and salvaged materials.

The cup of hot chocolate sits on a counter top was once a table leaf, while the beautiful hand-carved cabinets were recycled from an old armoire.

Some visitors comment that the kitchen feels like a boat.  Indeed, the utility, functionality and windows make one feel as if at the helm of a yacht.  The view differs in that one looks out at the vast desert instead of at the sea.

Building the Quonset Hut

The polycarbonate was placed onto the Quonset hut frame.

The process of building the Quonset hut addition took about 3 years and $20,000.

The old army-built Quonset hut was purchased in Albuquerque for $1000. They disassembled and hauled it to their location.

They poured a 2-foot slab foundation, then built a 3′ wall of concrete block to set the east-facing side of the Quonset hut frame on.

4 – 24 x 4 foot polycarbonate panels were attached to the Quonset hut frame.

The polycarbonate they used is a thick, translucent material that has channels of air within it that aid in the structure’s insulation, while it allows solar heat and light into the house. The polycarbonate has been treated with a UV protectant and is warrantied for 20 years.

The Original Adobe House

Adobe homes typically have thick walls.

The older adobe house has thick walls that help keep the house cool in the summer, and once warm, help it to retain its heat in the winter.

Adobe is one of the oldest building materials around. It is tremendously strong and the ultimate green building material. It is biodegradable (because it’s mud) while having longevity.

The original house was built in the 1800s.

It is a lovely house renovation that uses passive solar building elements with a south facing wall that absorbs and radiates heat.  They built an efficient Rumford fireplace for the times when extra heating is needed.

It’s always nice to see people who love where they live.  I count myself lucky to have been in their company.

Take a look at the gallery to see more photos of the Quonset hut-adobe home renovation.

Gallery

This article was based off of a submission to GreenPassiveSolar.

Photos of the building process are courtesy of David Van Dyke and Eric Thomas.  See more at: dvandyk.deviantart.com

The Parsons New School of Design and the Stevens Institute of Technology designed and built the Solar Decathlon home destined for the Greater Deanwood neighborhood outside of Washington D.C.

The home was also built in partnership with the Washington D.C. Habitat for Humanityand the D.C. Department of Housing and Community Development.

The Solar Decathlon home is moving to the Deanwood Community.

Meetings were held with community residents to guide the overall design of the home.

Demonstrating that efficient homes are for everyone, the home eventually will be moved to the community of Deanwood.  At the time of writing, this has not yet been done.

It has been a great learning experience for the students and it’s no small feat to coordinate, built, refine, then move a house to a new location.

The street facing north porch was shaded and was a welcoming space for socializing.

The north deck that faces the street allows for community involvement and socialization, while the deck on the southern side of the house is more private and has space for storage.

The kitchen had energy efficient appliances, wooden floor and had an ample amount of counter space.

The living areas of the house were predominantly white in color, which reflected the light to create a cheerful atmosphere, even on an overcast day.

This is not a passive solar house. Similar to inefficient houses that have the garage on the south side of the house, this house has plans for a storage shed on the southern side.

It was, however, built on the passive house standard, whose philosophy is to build a very insulated, energy efficient house. It has ultra-insulated walls along with energy efficient windows.

Energy efficiency is important and the passive house standard may be the best way of designing houses to be built without regard to the sun. It is, however, smarter to build with the sun in mind, since it is predictable, and we live in modern times where this is quite achievable. 

Stairs up to the mysterious ‘Light Loft’ area.

A second story was built onto the house and called a Light Loft. During the tours, a roped-off stairway led to this area, however, I’m not sure if it would have been another conditioned living space, or if it was simply a large skylight.

They utilized an energy recovery ventilation system with a heat exchanger that either heats or cools the incoming fresh air with the temperature from the old stale air as it leaves the building. This saves energy by transferring the temperature thereby not having to expend large amounts of energy to heat or cool the incoming air.

By building an insulated house and by utilizing energy efficient building materials and appliances, this house is built to use only approximately 10% of the energy that a typical house uses.

A children’s bedroom in the Empowerhouse.

Based upon that statistic, this would be a great way to build energy efficiency into neighborhoods across the country.

The 1000 square foot house also has photovoltaic panels on the roof of the house that help to supply the house with energy.

This was an important contribution to the 2011 Solar Decathlon as it combined a social activism with the practical need for housing.

The team tied for first place in both the categories of Affordability and Hot Water.

Take a look at the pictures in the gallery and the video below.

Photo Gallery

A screenshot of the final scores from the 2011 Solar Decathlon

Parsons New School for Design and Stevens Institute of Technology emPowerhouse Website: parsit.parsons.edu

See the original model of the emPowerHouse entered into the 2011 Solar Decathlon.

Solar Decathlon Main Website: solardecathlon.gov

Ohio State University created enCORE for the 2011 Solar Decathlon.

This home, however, changed dramatically from its first public model.  The most memorable feature was the interesting plastic siding.

The outside panels slid to block the sun from entering the house.

When I visited this house during the Solar Decathlon, while all the other teams gave informative tours, the Team from Ohio did not offer any additional information.  Thus, this article is based off of observation and the scant material that they provided.

The outside of the house had sliding panels that appeared to be a plastic product.

It would be interesting to see how this material weathers in the sun. I suspect that it would take a beating. The plastic panels were on a rail that allowed them to be positioned to block the sun from entering the house.

It seems that the wind could wreak havoc on this house.

I also thought the house had a dark and had a muted feeling.

Visitors touring the 2011 Solar Decathlon home.

There was an area that collected water between the porch and living area within the main home.

Scenes of water were nicely integrated into the overall design.

There was a system that filtered rainwater, however, I’m not sure if the water garden seen outside the bedroom window was part of the water filtration system.

This was a nice touch, but it did not seem to have integration with the surrounding environment like the house from the University of Maryland.

They tried to incorporate natural light in high traffic areas within enCORE’s 930 square foot design.

There were some interesting space saving features in the house.

The University of Ohio was an early leader of the 2011 Solar Decathlon with first place finishes in the important Comfort Zone category and they tied for 1st in the Hot Water category. The also had a 3rd place finish in the Energy Balance Category.

The team from Ohio had good placings in important categories, however, they fell short in the overall PR category, especially where the greater public is involved. They simply did not do a good job communicating aspects of their house during the tour.  It’s something to keep in mind when participating in the Solar Decathlon, otherwise bloggers will write very uninspired articles about your Solar Decathlon home, while gushing and raving about others.

There is more information to be gleaned about enCORE by viewing the photos and video below.

The Photo Gallery

While an early leader, the team fell to 5th place overall in the 2011 Solar Decathlon.

A screenshot of the overall scores for the University of Ohio’s Solar Decathlon home called enCORE.

See the original model that was submitted to the Solar Decathlon.

Check out Ohio State’s website to see more of EnCORE: solardecathlon.osu.edu

The Solar Decathlon Main Website: solardecathlon.gov