The House That Ingenuity Built
New Jersey’s Ecohabit Heads to National Competition
Zak Moy explains the difference between sholar shingles, that he is holding, and solar panels at a home the Stevens Institute is entering in the U.S. Department of Energy Solar Decathlon. The home is being disassembled in New Jersey to send to the contest in California. (Kevin R. Wexler/The Record/MCT)
Hackensack, n.j. — Plants grow on the roof. A device that looks like a crystalline sculpture sucks moisture from the air. And a sensor figures out when no one’s home, switching off the lights and air conditioning.
Welcome to Ecohabit, a two-bedroom house created by 60 students at Stevens Institute of Technology in Hoboken, N.J. They hope that its gee-whiz technology will help them win the U.S. Department of Energy’s biannual Solar Decathlon, which takes place this year from Oct. 3-13 in California. Twenty college teams, mostly from the U.S. but also from Europe and Canada, will compete.
The Stevens team also is hoping that the house, and the competition, will introduce builders and homeowners to efficient technology that goes beyond solar power. One of the features is a computerized system that monitors energy use and even the weather report.
“A lot of teams use this competition as a home showcase,” said Zak Moy, a 21-year-old recent Stevens graduate who worked on the two-year project. “We’re engineers, so we see this as a problem-solving competition.”
Under the rules of the competition, the house must be handicapped-accessible and solar-powered, and it must use products that are commercially available.
The 920-square-foot, one-story house has an appealing Prairie feel, thanks to its wood siding, horizontal profile and deep overhanging roofs, which extend the living space onto two decks. The technology may be sophisticated, but the design is simple: two rectangular boxes that lock together to form an L. One is the “dry” wing, containing the living room and a bedroom/den. That wing is faced with red cedar.
The “wet wing,” which is covered in fiber-concrete panels, contains the kitchen, washer/dryer, bathroom and master bedroom, as well as a closet containing the heating, electrical and air conditioning systems. The idea was to bunch all the plumbing close together, to minimize the distance that water must travel.
“The most efficient plumbing will have the shortest route from the heater to the tap,” Moy said as he gave The Record a tour of the home before it was dismantled and shipped to California.
The appliances, of course, are all the most energy-efficient available.
The wet wing includes a green roof and green wall to provide insulation and soundproofing. The roof will have low-growing sedum plants; the greenery continues down a side wall, which will have cubbies to hold plants, and onto a flat garden. All this helps absorb rainwater runoff.
The dry wing is roofed with solar shingles; it’s the only house in the competition that uses shingles instead of solar panels, Moy said.
The home has a market value of $300,000. Student designers tried to address the cost of environmental innovations, which are often an obstacle for the average homeowner or builder.
“A lot of people feel (energy efficiency) is too time-consuming, too costly,” Moy said. “Solar energy takes a couple of decades to break even.”
Research has shown that some green technologies deliver more bang for the buck. A 2011 study by the Rutgers Center for Green Building for the New Jersey Association of Realtors found that efficient framing and insulation techniques are among the most cost-effective green building tools. The use of solar energy, EnergyStar appliances and more efficient heating and cooling systems take longer to pay for themselves, but can still be worthwhile, while geothermal energy — which uses the temperature of the earth for heating and cooling — is the least cost-effective, the study said.
Moy said that one of the most useful elements in the Ecohabit house is the computerized monitoring system.
“The spirit of this competition is to show it isn’t that hard,” he said. “Just learning and evaluating how much energy you’re using can help you adjust your lifestyle.”
To that end, all the rooms have “smart sensors,” which are about the size of motion detectors. They detect information such as temperature, humidity, and how many people are in the room. The sensors are monitored by the home’s private computer server. If no one’s in the house, lights and air conditioning will be turned off. The system also tracks how much energy is used by the appliances or systems. Homeowners can access the information wirelessly through their smartphones or tablets.
“It helps provide feedback to help the residents make more energy-efficient decisions,” Moy said. The home’s computer system can even monitor the weather report — so it can tell you, for example, that you should wait to do a load of laundry till the next sunny day, which will create cheaper solar energy. Or tell you to hold off on watering your plants, because it’s going to rain tomorrow.
A new-age dehumidifier hangs on the wall of the dining area. Air is sucked in at the bottom, then dries out as it passes over tubes covered in a liquid salt solution, and comes out drier at the top. Condensation is sent outside, where it evaporates. The system takes about 200 watts of power, compared with 750 watts for a traditional humidifier, Moy said.
The walls contain something called biologically based phase-change material, a passive technology that helps stabilize internal temperature. The material, a bubble-packed soy-based paraffin, absorbs heat during the day and melts; as it cools and solidifies again at night, it releases the heat. So in the southern United States, for example, you can have temperature swings of 20 degrees a day; this product reduces that variation to 4 degrees, Moy said.
In a standard home, you have to run water and wait for the hot water to reach the faucet. In this home, water is heated on demand.
“It heats it when you need it,” Moy said. “You’re saving energy and not wasting water.”
When the water is hot, a button in the bathroom goes from blue to red so you know it’s ready.
About 60 students from a number of different disciplines worked on the project over two years. Architects and engineers occasionally clashed, according to Moy.
The architecture students would come up with an idea, he said, “and then the engineers come in and say, ‘You can’t do that.’”
After the decathlon, the house will be donated to a veterans’ resource center at California State University-San Marcos.
“What’s the point of just building a house to try to win a competition?” said Moy. “If you can help someone out at the same time, why not?”