UTC team designs energy-efficient home for Department of Energy competition

OK, the house needs windows that block most of the sun so the interior doesn’t get too hot during the summer, but they also must be transparent enough to use the winter sun for warmth.

OK, we’ll need an HVAC system that, along with keeping things cool and warm, moves stale air from inside to outside and takes some of the moisture out of the air, too, so the walls won’t be damaged by excess wetness.

OK, the whole house—from kitchen to bathroom to roof to outside walls—must be super energy-efficient with sustainable materials.

OK, how much is all this going to cost?

Those are some of the conversations that took place between students in the departments of Chemical Engineering, Interior Architecture and Design, and Engineering Management at the University of Tennessee at Chattanooga.

They found answers to all of those questions. Answers so good, in fact, the team is in the Top 10 of the Solar Decathlon, an international collegiate competition sponsored by the U.S. Department of Energy. The goal is for college students to “design and build high-performance, low-carbon buildings that mitigate climate change and improve our quality of life through greater affordability, resilience, and energy efficiency,” according to the Solar Decathlon website.

“The mission of the team is to provide opportunities for students to gain hands-on experience and unique training on the energy-vision building sector, which helps student to be in the future workforce in clean energy research,” said Sungwoo Yang, an assistant professor in the Department of Chemical Engineering who founded the group in 2019. “This is my mission. The team’s mission.”

The team is in the “New Housing” format in the Solar Decathlon, facing 10 teams from, among other places, Michigan, Indiana, Alaska, Australia and Canada’s British Columbia. The UTC team will present its project proposal at the Solar Decathlon conference in Golden, Colorado from April 22-24.

Putting together a group of 10 students from three different fields of study to work on a single project is quite a task, but to achieve such enormous success first time out is even more impressive, Yang said.

“This is a true interdisciplinary team,” he said.

Designing and building a house was a totally new world for him, said Kaid Black, a senior in chemical engineering and team leader, and it gave him another level of confidence.

“I’ve had to get out of my bubble and learn how to do something new,” he said. “So if I go into any kind of industry, I feel like I can apply that mindset and adapt to whatever environment I’m in because I know that I’ve done it before, especially with something like this.”

 

Project process

To enter the Solar Decathlon, it isn’t just a matter of “Hey gang, wouldn’t it be cool to draw up some house plans with solar panels on the roof and an energy-efficient ‘fridge?” Both of those were part of the job, though.

The team created a four-bedroom, 2.5-bath, two-story house that’s about 2,400 square feet in size. The house won’t actually be built this time, but that’s the ultimate goal in future competitions.

The team first got together in November and met every three weeks, but as the January deadline began crunch, they met weekly.

“We were brainstorming off each other,” Black said. “It definitely sparked us, our creative thinking. I would definitely encourage that kind of thinking. It helps.”

A narrative for the project is a criterion for entering the Solar Decathlon. Who was the targeted buyer? Millennials? Baby boomers? The elderly? Would the homeowners live there for a year or two, accumulate some equity, then move on? Or would they move in and stay forever? Monthly mortgage payments were a factor.

They decided the home would be built for a young professional couple in their 30s. The price of the home would be about $700,000, not out of the ballpark for a house that size with those amenities in Chattanooga’s St. Elmo neighborhood.

After those details were determined, rules said the home must be built on an existing site in the city. The team chose a site in St. Elmo, adding an extra level of difficulty due to the neighborhood’s historic district design covenants. They did that on purpose.

“It was all about our story and what can set us apart and what is going to be harder for us to do. That was our main goal,” said Ashton West, a senior in Interior Architecture and Design.

 

Interior Architecture and Design

Many may think that students in the department only pick drapes, furniture fabric, bath tiles and other surface things. That’s not even close to the truth.

Among other details, West and a fellow student Melanie Basil designed the house’s floor plan for optimum fresh airflow. They chose energy-efficient appliances. They calculated the roof pitch for the proper placement of solar panels.

Yes, they did pick the drapes, but they were chosen for their ability to block the sun at certain times of day, West said.

 

Chemical engineering

The chemical engineering students calculated the energy savings from the solar panels to see if they met efficiency standards.

In another task, they chose an HVAC system that could deal with the hot and humid climate of Chattanooga.

“We were really wanting to get a piece of equipment that would take care of that, which is an energy recovery ventilation system,” Black said. “The system specifically will replace the stale inside air with fresh air from outside. It will also remove a lot of moisture before it even enters a home so none of the walls get damaged with moisture.”

 

Engineering Management

Throughout the project, engineering management students kept an eye on the make-or-break— the cost of materials and construction to determine what the final house price would be.

Chelsie Ewing, a graduate student in the Engineering Management/Construction Management program, conducted the market analysis to make sure the price was within the overall range for homes in St. Elmo. The house site is in the 100-year flood zone, so she developed a system that harvests rainwater as one level of protection as well as choosing water-absorbent plants for landscaping.

“We felt it was necessary to have multiple options for water mitigation,” Ewing said.

 

How about this?

Whatever the task, ideas flew back and forth throughout the project. Some were used; some were tossed, Black said.

When the project first began, he and Chase Berta, another chemical engineering student, excitedly came up with an idea they thought was daring and could actually generate energy—make the floors capable of taking the kinetic energy of walking, transforming it into electricity and storing it in batteries.

There was just one problem.

“Yeah,” he said, then laughs. “The home would be like $20 million.”