The UT Solar House—A Prototype of Zero-Energy Living

I want to give you just a brief overview of
what is the solar decathlon so it kind of gives you an idea of the type of things that
had to be on our mind as we were starting to work as a team and putting together all
of our design ideas. Here you can see this is actually a competition
that's a department of energy sponsored event. And this was actually the 5th time, the 2011
event was the fifth time that this event has been held. And they actually set you up as a village
so they select 20 teams from around the world to actually be able to build the homes, bring
them over and set them up as part of the village for the competition.

And these teams are coming from China, Germany,
we had a team from Belgium. So it's truly an international competition
that all these technologies and ideas and culture are all being brought into the same
competition. A couple of the pieces that you can see here
are just kind of this idea of the neighborhood, which I think, you know we were speaking a
little earlier about this idea of being able to walk through what is a solar or energy
efficient neighborhood look like and the opportunity to see 20 different varieties of what that
is I think is a really important piece of the competition. We are actually just closing in, 2 weeks from
I think this time period, the 2013 competition will be opening out in California so this
is an exciting point for us to be able to see what the next group behind us will have
accomplished with the competition. So these are the areas that we actually we
pursing and so it's a true decathlon – 10 competitions.

You can see it's a pretty wide spectrum of
things that we needed to achieve. It wasn't simply the architecture of the building
or the engineering, but actually also how well can communication that; how affordable
is this product to the public. So being able to actually share each of these
as individual components, as whole systems, as a whole building and then also how we share
that with others made for a really interesting team make up that we had 10 disciplines from
across campus. All the way from architecture and engineering
that were expected in that. We had business students, we had graphic designers,
we had culinary students. We actually, as part of going through this
process, you're actually demonstrating daily life in the house. You're doing loads of laundry, you're simulating
showers, you're cooking dinner parties and we actually had to host our competitors in
our home and they got to judge us. But it was how much energy are you using on
your meal? How did it feel as a human being in that environment
enjoying that meal together- was it comfortable or not? So a lot of the pieces that James is thinking
about- about lessons learned with lighting and the color that are actually important
to that experience within the space.

Here's a little bit of a makeup of our team. You can see the wide variety of kind of where
all of these groups were coming from. I think to me it was a little bit unexpected
to see- we knew we needed graphic designers, but when we actually got down to it, having
a team that included 28 graphic designers was something that I had not anticipated,
but they made wonderful things like this image to help us convey our story. I think were a great part of helping make
us successful. When we looked at what were, as a team, we
all got together, all of the disciplines, and we sat in a room, and we wanted to know
what is important to the team.

What are the things that we want to keep in
mind as we pursue this design. And so you see here six concepts that we set
out as being, these are our goals. These are the things that we want to achieve. So having the transparency in the views and
obviously harvesting the sun's energy, which is kind of the point of the competition.

Leaving a small footprint. Having space that transforms, which allows
us to remain a compact unit. And then having the ability to control your
view and your ventilation. One of the other pieces that we wanted to
keep in mind is actually Tennessee as an inspiration for our team and our design. Where do we come from and why does that matter? So we were able to look as far back as cantilever
barn as a structure. There were reasons behind how all of that
structure were built. You have the loft to keep the feed dry, you
have the shelter for your animals. But also looking at things like the World's
Fair and the Department of Energy being located here. We have a lot of really great sources of inspiration,
both historical and I would say technologically-driven that we could look to I think really helped
our team when you are taking a message from Tennessee to go up to the National Mall and
present that to the world. I think that was really strong message for
our state and our university.

Hopefully you can see the contrast here with
the lighting. The idea of living compactly. We wanted to be able to take this as one unit. We had studied all of the previous hoses and
a lot of other examples of modular homes. We actually learned a lot from the teams that
went before us. The complications they faced when they took
multiple units and tried to put them together. Even as simple as the things that we learned
from trying to put it together ourselves with the little prototype house. We actually have one unit and you can see
that we have two enclosed what we call cores, so there's actually a core that incorporates
all of the mechanical and electrical equipment. And then on the opposite end is actually what
we sort of referred to as the private core. It's enclosed as the restroom space and then
on the outer wall that is actually where the, it's not really a Murphy bed, but a bed that
actually slides up into the wall, so it's very similar to a Murphy bed.

The idea is everything between those two cores
is able to be flexible throughout the day, throughout the seasons so that as you're entertaining
a dinner party that you have the ability to entertain that with lots of space. When you're just at home and you want to read
a book- all of this had every function in mind. And then you can see that the majority of
both of north and south walls were glass.

The thickness of that was, so you can actually
see what we chose to do was the southern facade is actually on your right. We chose to have the larger lights of that
be clear glass. Part of that was allowing us to collect that
light and that heat from the southern side of the home. On the northern side we actually chose to
use a frosted glass, which worked for our cases, but it actually also supported the
privacy for the way we were oriented in the neighborhood so that our front yard had kind
of a built-in blind system in a way.

But this facade system actually we'll get
into in a few minutes, but it's a newer system in homes that we actually was lessons from
the greenhouse space. But you'll see the lighting that's incorporated
around the edge. These are actually color-changing LED lights. We were actually able to do some programming
that we could set them to be more natural tones. In the morning you can set it to have a little
bit more of a red color that a little bit more of mimicking sunrise. In the evenings, give it a little bit more
of that orange sunset glow. There were a lot of really interesting things
that we could do with that throughout the week. Even with hosting the dinner party- being
able to set that color so the space felt more comfortable and more intimate.

I think they are set on Tennessee orange in
this photo. It's a little washed out. This is another image of the interior looking
back- I apologize, let me- This image is actually looking from the kitchen space back towards
the living room. You can see the foot of the bed is projected
just a hair there. This is actually looking back towards the
kitchen. One of the pieces we wanted to make sure we
did is everything had a purpose. These walls actually, they're not just walls,
they actually hold pieces of the home. This is actually, the kitchen doors are able
to fully enclose that, but all of the oven, the dishwasher, everything is incorporated
into the cabinetry. You have one solid piece to it. This drawing is a section through one of the
outside walls. If this one is facing south, this is the outside
of the wall.

Everything you see in black is slicing through
that wall. This depth between the inner and outer glass
is on the order of about 14 inches. This was the concept that we started out with
the UT zero-prototype. It was four feet and it was only switchable
by human moving the wall back and forth. Now we've collapsed this down to that 14 inches,
we find that it still has the same thermal efficiency as it did before in terms of still
being able to heat air for us, but it takes up much less area of the building. Plus, instead of having the doors go through
this zone, we have the doors go around on the short ends of the building so that we
don't break that zone of heat gain every time we open and close the door. And over on the side I think you can see a
little bit of our dynamic modeling. We did several different tests on the structure
as we were designing it to see where the light and the heat would be in the space.

To give you a little insight into the next
slide, there is a flow of air that we channel through this cavity. Much more clearer- well, anyway. So up here, this would be the heating mode. Imagine that what you're looking at is the
section of our home so that that line represents the south; this line represents the north
wall. And this would be the sunlight that is impacting
it in the winter.

Again, as in the prototype, that winter sun
comes in under the overhang. That winter sun hits the glass unimpeded as
let's say we have a 30 degree temperature outside, we can raise that temperature about
30 degrees in that cavity. So that we're allowing 60 degree air into
the home. If the set point that we want to reach is
72, then that means the heat pumps, and we had two mini-split heat pumps, only has to
raise it 10-12 degrees for you to be comfortable. In that regard in the winter, during the time
that we have sun, two-thirds of our heating is already taken care of just by the orientation
and design of the envelope. Now to prevent heat loss on that north facade,
when we're done with that air inside, we exhaust a little bit of it out that north facade. So what's happening is there's continuously
a string of air that comes inside the home. The mini split heats it or cools it as necessary
and then we exhaust it out the opposite side.

This would be the winter heating mode: in
on the south, out on the north. Now the opposite happens in the summer. In this version we're getting free, basically
free heat. But in this version, we're actually creating
what we call a dynamic R value or a dynamic insulating layer. Here, if we have a hot day, we have 90 degrees
Fahrenheit, but we're pulling that air in on the north facade, which would be in shade. We're bringing that inside and then we're
using that air to be our fresh air. We're cooling that as we need to and we exhaust
a little bit out of that on the south side, which is also now completely overhung by that
sun screen.

We're creating that dynamic barrier of insulation
around the house. What we found in this is that we're able to
achieve between about an 18-25 r value, which to put it in terms of standard residential
construction, that is about the same or better than a 2×6 stud framed wall with insulation
jet board sheeting and brick. And in our house it was a wall that you look
could look completely through. There's some technology in this home. This is some of our HVAC system components. We used two mini-split ductless heat pumps
in the home. One is in each of those two cores that Amy
showed you in the plan. Together it's about a 1.28 ton capacity for
cooling, but we don't actually need that much. The reason we have more capacity than we need
is because of the rules of the competition. We would have an open day when we had tours
of the general public coming through the home.

At 5:00 we had to shut the house, get everybody
out and by 7:00, about 5:30, 5:30, oh my goodness, we had to have the house at operating temperature
to be able to start the monitoring competitions. We had to have extra capacity to even be able
to heat or cool that house to get it to our set point immediately. That's why we have extra capacity.

And then this is our energy recovery ventilator
that moves air between the two facades. The energy ventilator passes the streams of
air so that heat is transferred from one side to the other, but not the air itself. It's a very efficient means of ventilating
a home without changing the interior temperature. We benchmarked the home. You can see on this chart- there's the Living
Light house in blue and the average builder home benchmarked to 1,000 square feet is in
red. Overall, we're using about half the energy
per year to heat and cool that house. And now we talk about the solar array.

The array that we used on the previous project-
the UT zero prototype- was a bi-facial system made by Sanyo. We were very interested in sourcing as many
American made products as we could on this home, so we used Solyndra. If anyone has heard of Solyndra, it bankrupted
itself about a month after we bought our panels. But, I have to say, it's a very good design
and I can show you why. This diagram, you're looking at three of the
Solyndra tubes in section. This is our reflective roof and this would
be the direction of light. So the reason this 360 degree tube of photovoltaic
or energy-producing skin makes sense is because it doesn't care where the photon hits it.

As long as light hits it somewhere, it makes
power. That works for direct, ambient light and also
any light that misses it on the first pass and bounces up actually can produce power
on the backside. Hugely valuable for us. I really do credit this for being the reason
why we got first place in energy production. We were able to make power earlier in the
morning and later in the evening that most people. This diagram is a little bit hard to see-
there's a grey line that peaks. There's a blue line that's sort of more of
a gentle curve with broader shoulders. The blue line represents the energy production
over the course of the day for Solyndra and the grey is for a standard solar panel. A standard flat-paneled collector is going
to peak higher than we will- they will produce more power at noon, but we are actually able
to produce early in the morning and later in the afternoon, which meant, if you look
at the area under the curve, we had more power.

We also did exhaustive modeling of the home
before we even took it to Washington to make sure we had the equipment and we had the energy
budget to do things correctly. Here you can see- this is the energy use as
it broke down for the competition. Heat is pretty much 40% of what we used. Lighting was very small; the water heater
was 21 and then we were composed it against a chart of the number of days of the competition
and we looked at the energy produced versus the energy consumed and so this chart- the
black is what we produced; the red is what we consumed. In some areas you can see that we had peaks
of consumption that did not hit the peaks of production and that is not unusual. The great thing about this solar decathlon
competition is that it does push people in the direction of being grid-tied.

The intent is to create net-zero, no necessarily
free from the grid. If we again, take the area under the curve,
we produced far more power than we used, but we did not necessarily line up a peak in production
with a peak in use, which the way I think any modern grid would work. Over the course of the competition, we put
far more back than we used, but on certain times, our peaks did not align. So that's something that myself and one of
my colleagues at Oak Ridge National Labs, Bill Miller, are looking at – are there ways
to make those coincide more. But to be honest with you, I think the best
idea is to have a home that has the ability to produce its own power, but is always grid
connected. That way you always have the ability to push
it if you don't need it and to pull it if you do. This one, I think, is kind of interesting
to me.

First we have total energy consumption over
the course of the year. We've again benched marked a similar-sized
builder home at 1,000 square feet. Ours is approximately 1,000 square feet in
blue and you can see that we're somewhere between a half to two-thirds better in terms
of what amount of energy we use over the course of the year. Part of that is building small. Part of that is building efficient and then
the other part of that is being able to operate it efficiently. This is an interesting diagram for me. This is the percent of energy the Living Light
house components used compared to a standard home.

This is a standard home- this 100% mark. Our downdraft cook-top vent used exactly the
same amount of energy as anyone else's downdraft, cook-top vent. But where it gets interesting are things like
lights. We used about 12 % of the energy of a standard
home for our lighting. We had a mix of light-emitting diode in our
floors, light-emitting diodes in our can lights in the ceiling and then we had strip fluorescents
that had a step dimming feature for general illumination. Well-lit during the evening and then day-lit
during the day and that translates to the 12%. The other interesting thing was our refrigerator
and freezer. We used a refrigerator that was an American-made
product, a rather small, I shall say refrigerator, not a full size as you would typically imagine. But what we were able to do with that was-
it had two compressors in it. You'd put a lot of groceries in it, it runs
both compressors, gets everything cool and then to maintain temperature, it steps back
to one compressor. What also worked in conjunction with our water
heater, which was at about less than 40% of the energy used in the standard home water
heater.

It was a heat-pumped based water heater. We put it in the mechanical room where we
put all our waste heat items. We had the inverters for the solar system;
we had the washer and dryer in that room; we had our computer in that room; and we also
had the back of the refrigerator where the coil is was open, dumping all of its waste
heat into that mechanical room. So all of that heat that we would have to
condition out of the home anyway- the heat pump drove it from the air in that mechanical
room straight into our hot water tank. We got first place in hot water. There's some interesting things that weren't
necessarily complex designs, they were just smart thinking that got us ahead.

We did have an automation system for this
home. It gets pretty complicated. We have all of the systems that have to work
in conjunction with one another. This is one where I really like to talk about
how far we've come. This was based on an iPad. We were platform agnostic. It could have been an iPad; it could have
been an HP device; it didn't matter.

This is the screen you would get because you
would dial up through a web connection. Its default setting was it would tell you
interior and exterior temperature. It would give you some hot buttons to go to
certain functions. Then it had the menus on the side to control
everything. We can control the blinds from there. We can control the media, temperature. Here's what it looks like when you pull up
your thermostat. You can control everything from that iPad. Here's the lights. Here are the floor lights: the red, green
and blue channel. If you want to dial in Tennessee orange, this
is where you'd do it. And then this- this was our one-button setup.

We called these moods. This would be something where if you're in
the home and you're setting up to entertain, which is the cocktail glass- I love that logo. You're about to have folks over for a party
in the evening, if you press that one button, it will put the exterior blinds to a preset
where you want them. It will set the mood lighting whatever color
you've set. It will turn on the lights maybe in the dining
area, but dim the ones in the kitchen area. It can turn on the light outside to welcome
guests. It can turn the stereo on the channel you
want it to be on all with one button. Because we have so many complicated systems
and we did not want this to be something that felt like an onerous task every time you had
to set up for an event. That was pretty nice. I think the opposite of this would be vacation. You have one button that you'd press on the
way out that would put everything – you know, close all the blinds, turn all the lights
off – put everything in power-saving mode and potentially even send you an email every
once in a while and tell you what's going on.

That was great. What was interesting about this was, and this
a little anecdote that I'll tell you very quickly. We bought an automation system from a major
manufacturer because no one made anything that could handle all the complexity and multiple
channels and sensors that we had. In fact, the program that we had was created
for an automotive manufacturing plant where you might have 16 robots working together
to weld together a car body. We had our graphic designers and our programmers
create this overlay that went in front of a very generic engineering software. We then attached it to all of these various
pieces of equipment that had never been attached to this type of software before. When the system worked, it worked beautifully. When it didn't work, nothing worked. We were on the bleeding edge of making this
system work. The reason this is fascinating to me is about
6 months ago, I bought my girlfriend a Nest thermostat. Do you know what a nest thermostat is? If you don't know, look it up. Designed by the same guys who did the Apple
interface.

It does everything this system did with the
possible exception of the moods page- $200. Connects to Wi-Fi to your computer. You can dial in from your cell phone. You can set the temperature you want. You can set days in advance- vacation settings-
for $200. I won't tell you what this cost because it
was more than $200. It's interesting, between about 2010 and say,
2012-2013, there's been a huge change in this not just because we now are learning how to
have this technology because we've always had it, but now there's a demand at the residential
level for people to actually do this.

I think that's huge. We wanted to share a little bit about…you
know that's a lot of information about how we approached the design to meet the competition
standards. We wanted to share with you how we did- We
placed 8th overall. I'll say we did the calculations- we were
an expensive project to say the very least. There were a lot of decisions that we made
early on about what we wanted to achieve through this project. To us it was more important to pursue innovation
and some of these bleeding edge ideas that actually cost more money for a prototype. We were last place in the affordability in
the competition, but placed very well in all the other. You can see there, a number of competitions
we actually did place first place. Several third place in there as well. You can get an idea of how we fared in all
of these different categories. And then also on the right hand side is how
we fared against our competition, which, this is a somewhat difficult diagram to read.

We're here at A, but that just means that
we bet Massachusetts, Canada, Florida, Appalachian State, Tidewater, China- the entire nation
of China, which was great – Belgium, New York, New Jersey and Florida. When I talk about the things we wanted to
achieve through this project, one of those pieces was okay, we do this project, we take
it to the competition, and then what? A lot of teams actually have buyers arranged
or they take their project and they place it on site and it kind of loses its life from
that point. One of the pieces we actually did was in making
a single unit and making it easily transported, we were able to take this on tour. When we drove it up to Washington, D.C. and
were able to just pull back the covers and the other teams realized that our house was
already done, that was a fantastic moment, but when we showed up in Nashville and Memphis
and Chattanooga and had the opportunity to take it back to Washington, D.C., the mileage
that we were able to achieve with being able to talk to schoolchildren, homeowners, professionals
from architecture, energy, engineering, the whole nine yards.

The ability to actually share the story and
talk about the individual pieces of the home and the bigger idea and then of course the
University of Tennessee. One of my favorite days- we had two days of
middle school students who came through when we were in Washington for the competition. When you're standing at the end and you're
handing them their little brochure and their button, they were just, "I'm going to the
University of Tennessee!" It just makes you really happy to be able
to stand there and be a part of hopefully bringing in some new recruits and 10 or 12
years.

We're looking for a big, big increase in enrollment. If there's a spike, we're taking full credit
for that. These are a few examples of the different
settings we were able to take this home. When we took it to these places we were actually
able to leave it for several weeks at a time and have it staffed and reach out to the local
schools and reach out to the professional organizations to host specific events as well
as be a part of festivals. Part of what we do, we don't just design,
we don't just build, we also evaluate. That's one of the wonderful things we get
to do because we still own our home. Most builders and architects, once they've
finished with building that project, they don't get to monitor anymore. They don't really get to know how it performs
in the real world. We've had the opportunity to do that. Dr. Bill Miller, who is a joint appointment
with UT architecture, engineering and works at Oak Ridge National Lab, has been monitoring
the home with his graduate students so we have a sense of exactly what sort of temperature
flows are happening in the summer and the winter conditions in our house through our
double-facade system.

We're taking enough data on that, so very
soon we'll be able to know A) if it performed as we intended; and B) if it did not, what
could we do to make it better. We're bench marking a code, and he's almost
finished with this, so that we can really, in the future instead of having to build as
many prototypes as we did, we can model this on the computer very quickly and get very
clear, clean data on this.

That computer tool is very close to being
licensed to a window manufacturer right now. That's one sort of great effect of this is
by putting this much effort into designing these new technologies, people are interested
in that, so they are coming to us asking for it. We've also had some interesting encounters
with some developers who are interested in this idea of compact living. Just this summer we ran a studio with some
developers from Chattanooga looking at how we could reuse shipping containers, which
is sort of a popular idea, but hasn't really been tried yet in this area, so we looked
at that. We also are looking at other projects later
on that deal with this design, build, evaluate theme. We had this house along with the new Norris
house, which is another project of the architecture school, at the American institute of Architects
convention just a month ago.

This is something that seems to be a direction
that people are very interested in. I think it's helped us attract some of the
best and brightest students. We are very interested to push that forward. The closing piece here- we just wanted to
share with you. Not only did we have hundreds of students
and 10 departments and the support of the University and all of its branches, but the
support of industry to engage with us in how do we approach this project. They donated products. They stayed in touch with us just like James
was speaking- the glass manufactures, all the components and pieces that went into that.

Those groups are very interested in not only
in keeping in touch with each other to possibly look at deploying some of these systems, but
also wanted to know what data we're getting back and what kind of feedback we can give
them on this system. All of these people made that possible for
us to build this project and dream. It was really nice, two weeks ago, three weeks
ago, the Southeast Sustainability Summit was in Knoxville and about 25 folks came out to
the house for a tour. Many of them are from these companies up here
at the top. It was great to have those people in the same
room again. I think it was great for them to see what
our students can do. I think we talked about before we started
this presentation, sort of as a sidebar, the students who have worked on this project-
whether they were in architecture, interior design, engineering, mechanical, electrical,
they have found jobs placed with some of the highest and best, kind of most cutting edge
companies because of what they did on this project.

Not only is this sort of work in demand by
the students who come here, it's in demand by the folks that hire our students. It's a really good link between those two. This image was taken on a cell phone. This is Kate Armstrong, one of our grad students
when there were in Washington the second time for the Smithsonian Folk Life Festival, it's
pretty nice to be able to sit on your front porch of the house you design and build and
watch fireworks on our Nation's capital right there with the Washington Monument in the
back.

I think this was a really awesome event. We had 25,000 people see the house just at
this one event. We were right there at the Metro stop on the
National Mall. We had that 105 degree heat wave in D.C. that
week. We had a solar house, it was not grid tied. We had our air condition running. Both doors were completely open because people
were just walking through. We were able to show them what it felt like
to actually be in a solar house in 105 degree weather and it felt pretty good. In addition to the heat wave, they also had
a huge storm that came through. Most of the other exhibits had posts and tents
just like you'd normal see at festivals. I'm sitting back in Knoxville unable to go
with the team up, and watching news reports of tents scattered across the National Mall. I think our structure was the only one that
was still intact. Nothing happened to ours. All of our students went out and helped everyone
else put their tents up because we're volunteers and that's what we do.

One other piece that we wanted to offer to
you all is actually the home is here on campus, on the Ag campus. It's actually sitting at the UT Gardens. There are hours that it is open. It's usually open around the time of the Farmer's
Market. We encourage you to go out and see if first
hand and let us know what you think. Thank you..

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