In April, Purdue University kicked off a three-year undertaking to prove that high-performance dwellings needn’t necessarily be built from the ground up with all the innovative, energy-saving bells and whistles already attached.
The guinea pig? A three-bedroom Craftsman-style bungalow built in 1928 and located just steps away from Purdue’s West Lafayette, Indiana, campus.
The Purdue Research Foundation-owned single-family residence is a charming piece of real estate with its low-pitched gabled roof, column-supported front porch, original brickwork and beautiful interior woodwork. It's a well-kept, modest property that plays nicely with the other older homes in the neighborhood. But much like other American homes of the same style and vintage, the home at 545 Hayes Street was a drafty, energy-guzzling 2,800-square-foot nightmare.
During a ribbon-cutting ceremony this past fall, the home was christened as ReNEWW — short for Retrofitted Net Zero Energy, Waste and Water — House, a veritable toolbox of cutting-edge green home tech. Like with all net-zero projects, the goal is for ReNEWW House to annually produce as much energy as it consumes.
Photo: Purdue University/Mark Simons
This isn’t the first time that Purdue has ventured into net-zero building territory: Purdue’s super-efficient INHome was the second place overall winner at the 2011 U.S. Solar Decathlon. Equipped with a very Solar Decathlon-esque name, the ReNEWW House, however, is the school’s inaugural net-zero retrofit project.
Launched in partnership with Michigan-based home appliance behemoth Whirlpool, the ReNEWW House is a living laboratory in the truest sense: the home’s tenants, graduate students/engineers enrolled in the Whirlpool Engineering Rotational Leadership Program (WERLD), are researching and living in the home during two-semester stints.
The ReNEWW team has had the work cut out for them from the get-go: the home, leased by Whirlpool from Purdue during the project's three-year run, initially scored a 177 on the HERS (Home Energy Rating System). Translation: it was 77 percent less efficient than an average new home. The score has already been driven down significantly to the single digits.
Explaining that the basic aim of this deep-green conversion project is “is to take an old home and see what we can do with it,” Eckhard Groll, Reilly Professor of Mechanical Engineering and director of Purdue's Office of Professional Practice,” also notes that the process of transforming a leaky old bungalow into a tightly sealed, solar panel-topped research project has been a challenging one. “We struggle. It’s not that easy,” Groll, who is serving as the ReNEWW project lead, says. “We wanted to set a far-reaching goal to get people thinking about it.”
One of the most formidable early challenges was also the most crucial: the installation of a photovoltaic array on the home’s lovely but difficult-to-work-with roofline that, as Groll points out, “isn’t ideal for solar.” The array in question is composed of multi-tasking combined PV-thermal cells developed by SolarZentrum North America.
Photo: Purdue University/Mark Simons
Another major — and necessary — early task was sealing up the home and plugging cracks, holes and other leaks great and small. Project sponsor Honeywell stepped in with its Solstice Liquid Blowing Agent, a new, high-performance blowing agent boasting significantly less environmental drawbacks (and potential health impacts) than hydrofluorocarbon-based blowing agents. The insulation itself (the blowing agent is what causes the insulation to expand) is closed-cell polyurethane spray foam insulation manufactured by Lapolla Industries.
Ply Gem, which supplied triple-pane EcoSmart windows, custom exterior fiberglass doors and insulated sliding and trim with a high amount of recycled content, is another major project sponsor that was involved with some of the more heavy-duty retrofitting work that took place over the summer. Locally based green home building firm Green Goose Homes served as project contractor.
With the shell of the home sealed up and a PV/thermal system in place along with a geothermal system from Enertech Global and smart thermostats from Nest, the ReNEWW team has been focused on applying/testing/monitoring an array of additional energy-centric technologies since September. An extensive study of the home’s indoor air quality also commenced in the fall.
Eventually, the two “W’s” — water and waste — will take center stage as additional phases of the project get underway. Groll refers to the zero-waste goal as a lofty one but one that he and the rest of the ReNEWW team will enthusiastically tackle. Whirlpool-developed appliances (naturally) play a significant role in the water and waste departments, including plans for a heat recovery system that will draw waste heat from the home’s major appliances. A graywater system that harvests wastewater from sinks and showers, backyard composting and an indoor hydroponic garden are also in the works.
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