Shooting for net-zero: Equal energy in, out of the home
From the street, the row of windows in Dave Blair’s home in Monaca makes the 44-foot-long sunroom look well-suited to grab light.
The 14 solar panels and thermal collector above the room hint something different might be happening.
“It is the nicest furnace you ever could stand in,” Blair says. The sunroom is the main heating device in the house that he hopes will produce as much energy as it uses, otherwise known as being net-zero.
“I wanted to set a path,” says Blair, a retired architectural drafting teacher. “I wanted to make a home that other people could look at and say, ‘We could do that.’ ”
Blair and his wife, Melody, set a challenge for themselves, he says: building the home for only 10 percent more in anticipated cost so the energy savings pay for the additions faster.
He believes he accomplished that goal in the $315,000 home, which has 10-inch-thick walls insulated with dense-pack cellulose.
Elliot Fabri Jr. from EcoCraft Homes, the South Fayette-based builder of modular housing, says the company and Blair acted as co-designers in a way.
Blair came up with designs and ideas of how to be energy-efficient, and EcoCraft put the planning together and searched for products and material to make it work.
For instance, Fabri says, the triple-paned windows are a product of Ireland while the 12-inch-thick precast concrete foundation came from Specialty Precast Co. in Butler County.
The target is a low score in the home energy rating system, or HERS — a set of guidelines that has become a standard in building.
Residential Energy Standards Network, better known as Resnet, is a California-based nonprofit that put together the rating system that established a HERS rating of 100 as the standard for built-to-code new homes. Lower is better in the system, with a totally efficient house getting a zero.
“We hope to have HERS rating of 16 or lower,” Fabri says of the house, where the Blairs took up residency in July.
The heart of the home is the sunroom. The full line of triple-paned windows runs below an overhang that Blair and Fabri worked on to capture as much sunlight as possible in the cooler months and to shield it out on hotter days when the sun is higher.
“It’s really no big deal,” Blair says. “It’s all thinking that was back in textbooks in the ’80s.”
Heat in the 44- by 7-foot space is captured by sealing off the room with thick doors and windows in the interior walls. Once it is trapped in, the interior doors and windows are opened, allowing the warmth to heat the rest of the house.
Ducts at the top of the room have fans to blow some of the air into bedrooms on the second floor.
The windows point south, facing the sun at its highest and warmest, one of the crucial elements of design.
Blair ended his teaching career in Everett, Bedford County, and decided he wanted to return to his hometown of Monaca and build an energy-efficient home.
To do that, he says, one of the main factors was finding a property where the home could be placed to take advantage of the sun’s path.
He found the property and began searching for builders and contractors who could help him reach his goal. The hunt wasn’t easy, he says, because he got into arguments about his ideas and theirs. One construction firm was intent on using concrete block as a foundation, Blair says, regardless of his desire to find something more efficient.
He found EcoCraft at the Greater Pittsburgh Home & Garden Show, Downtown, in 2013 and appreciated the company’s ability to work on all aspects of the project.
“They can do it all,” he says.
The success of the heating system won’t be determined until winter, Blair says, but on a recent cool night when the mercury dipped to 39 degrees, the temperature in the home went down only to 69 from 71.
Measurement for a HERS rating takes place over a period of time, Fabri says, and includes a test using a blower door. In that test, a door with a fan is placed at an entrance and sucks air through the house to detect leaks and determine efficiency.
The house collects solar energy for electricity from 14 panels on the roof, where there is a thermal collector to heat water, to a degree. Hot water for showers or cleaning is warmed to a higher temperature by a gas boiler.
Electric production is routed into the area grid but can be used as a stand-alone source if there is a power failure, Blair says.
The boiler can come into play on colder days by acting as a backup for the heating system. Preheated warm water will be heated more and pumped into an array of pipes near a fan that will pump warm air into the house.
“It is a forced-air hot-water system,” Fabri says.
Blair seems ready for the winter test ahead. He believes the household might be using a little more energy than he planned because it was designed for him and his wife, but her daughter, Emily, and their grandsons, Trent and Trystan, have joined them.
“So we are taking more showers than I thought, but this house is still beyond what even I thought I’d have.”
Bob Karlovits is a staff writer for Trib Total Media. He can be reached at [email protected] or 412-320-7852.