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One farm in the Ozarks is the location of a series of unique experiments in sustainable living. If these experiments prove successful, it would greatly affect the future of sustainable technologies and how people think about building their homes. KSMU’s Shane Franklin had the opportunity to tour the farm, and has this story.
Rockspan Farm, the home of Dan and Margy Chiles, is unique in so many ways. They wanted to build a farm that could be an example to others, and a test lab for experimental technologies they’ve been personally developing over the years.
“We are trying a number of new technologies here to make houses more efficient and to make a livable space without having to burn a lot of coal. That’s the whole idea. The backdrop to this entire project is that the Earth is warming, the climate is changing, and everybody has to do their part. I’ve been talking about this for years on city council and I thought, now that I have my own chance to do this, I’m going to do it right. We’re pushing a lot of technical envelopes here, but so far so good.”
Talks began with a local architecture firm in June of 2010, according to Rockspan.com, the farm’s official website. The farm is now nearly complete.
Rockspan is comprised of a house and barn, with a southern roof covered with solar technology. The first thing you might notice about the house as you drive up the long drive, lined with trees, is that this house is in no way ordinary.
The first thing you’ll notice about the house at Rockspan Farm is its construction- concrete and white oak. This creates an incredibly durable frame. Chiles describes the unpainted concrete walls as having a Rorsch-block effect, which he finds beautiful. There are other reasons for the unique construction, which well speak of shortly.
The next thing you’ll notice about the house is the mosaic above the front door. According to Chiles, the intricate mosaic depicting the sun, with a copper sculpture named “Spirit,” in the center, is made up of nearly 1800 small pieces of wood gathered from 64 different types of trees by Chiles’s grandfather, R.H. Chiles. Dan Chiles built the mosaic himself, and included a testament of love, a small heart with “DM” in the center, for Dan and Margy Chiles. Chiles says this mosaic above the main entrance to his home is a tribute to his grandfather.
After taking in the initial uniqueness of the home, you’ll likely notice landscape of Rockspan. The house and barn sit in a green field, perched on a hill overlooking a lake, several springs, a waterfall, a natural land bridge for which the farm gets it’s name, and access to the Sac River, which feeds into Springfield’s main water supply.
[The natural spring by the Rockspan land bridge]
Chiles says he plans to utilize the space and abundant water, some of which he’ll gather off of his roof and store in a 4,000 gallon water cistern, to grow crops. He would not be the first to utilize the unique resources of this landscape though.
“This has been settled by natives for at least 9,000 years. Maybe 10,000 years. So, this has been cultivated and used as an agricultural source for that period of time, and here I am arriving pretty late, but still determined to be sustainable.”
To measure just how sustainable Rockspan really is, Chiles has followed LEED guidelines, or the Leadership in Energy and Environmental Design. He’s striving for Platinum status, the highest status LEED offers, but he says that the one aspect that might keep the farm at Gold status is LEED’s insistence on recovering unused urban space. Chiles expressed that LEED has yet to fully appreciate the value of building a small, sustainable farm.
“In every other regard, I’ve gone through extraordinary lengths to make sure that this house really lives up to the spirit of LEED, which is- Can you justify building a new house, is it sustainable, will it last a long time?” Which is really what we have going on here. Because when you build a house out of concrete and white oak, you’re really making a statement. You’re saying ‘I built this, and I want it to be around for a long time.’”
Now, back to the unique construction of the house at Rockspan Farm- There are two reasons for the concrete construction. Chiles says the home is designed to be both tornado resistant and net zero energy, which means that it produces more energy than it consumes. The concrete walls are key to both of these factors.
“What’s unusual about this home is its strength. It has three inches of insulation in between and layers of concrete on either side, so it’s built like an Oreo cookie. Inside each one of those layers of concrete are sixteen half inch steel cables. Those dudes are stretched and then they pour concrete on them and then they cut the cables. The concrete walls are perpetually under tension and since they pour concrete on them they are also under compression.”
Chiles noted that after what happened in Joplin, he wanted to be sure to give his family a fighting chance. But, the concrete walls have another, less obvious, function.
“The other unusual thing about the house is, I’m trying to heat and cool the house with this solar energy I have available. It has two miles of tubing inside those concrete walls.”
These tubes hold a fluid that transfers the energy from the sun-warmed exterior walls to the cooler interior concrete walls, heating the home in the winter. It can also do the opposite in the summer, taking the heat in the house and moving it through the tubes to the cooler northern wall, or to the barn. The heat then can be dispersed into the environment at night, cooling the entire farm system.
“If you had to visualize what this house is, it’s like a vascular system in a person. So, if you peal back the layers of skin you see this wonderful network of red and blue tubes. Of course, that’s doing lots of things. It’s transferring blood from place to place, nutrients, oxygen, but it’s also transferring energy. That’s how we get energy from our core to our exterior and back and forth. That energy transfer is basically what this house is doing, except with concrete instead of skin.”
This system is similar to a more commonly used form of alternative energy; known as a ground source heat pump. But, at Rockspan, Chiles wanted to try something entirely new.
“Most ground source heat pump systems have deep wells or coils buried into he ground, but I thought- That’s cheating! There are a lot of places in the country where you simply don’t have access to the ground water or have access to a big green field, like I have here. So, what would it be like if you could use the house itself to heat and cool the house, through the energy that’s in the walls? That’s the great experiment that were engaged in here.”
This is not the only experimental system that Chiles is developing at Rockspan.
“I want to be net zero energy. That means that I make as much energy in the course of the year as I’m consuming. To start that process I’ve put 10.5kW of photovoltaic panels on the roof of the barn. Normally these are about 17 percent efficient, so that’s pretty standard in the photovoltaic world.”
In other words, these solar panels turn 17 percent of the energy that strikes them from the sun into electricity.
“We weren’t satisfied with that, so we built a heat exchange structure underneath each one of these photovoltaic panels.”
This is where the experimental part comes in. The photovoltaic panels are located on top of the barn, a short distance from the house. Because the panels set in the sun all day, they begin to warm up.
“There is warm water coming off the backs of the photovoltaic panels; those are technically known as PVTs or photovoltaic thermal panels. What’s happening here is the pumps are pushing the water through the photovoltaic panels, it comes back and goes into the slab floor of the barn. It’s free, for the price of running this little pump.”
Chiles says that when you combine the electrical and thermal energy coming off the PVT collectors, they become capable of capitalizing on 35-40 percent of the energy freely given by the sun. The thermal energy, from the collectors, provides heat for the barn. The electricity generated from the array powers the entire farm.
“Keep in mind, all that was done in the Ozarks. We designed and we built those PVT collectors right here. We’ve gotten a lot of interest for them, because incremental progress in the photovoltaic world is a percentage here and a percentage there, but overnight to double their performance? That’s pretty amazing.”
Other sustainable and energy efficient technologies at Rockspan include, but are not limited to, a highly efficient septic system to ensure no leaks into the ground water, and a residential fire sprinkler system running through the whole house. In addition, the house has natural ventilation utilizing a spiral staircase that runs from the basement to the penthouse on the roof, as well as brilliant sun tunnels providing passive lighting through the whole house.
If you’re interested in more information on other technologies utilized, or keeping up on the progress of the Rockspan experiment, you can find a large resource at Rockspan.com.