web analytics
keyetv.com Austin News, Weather, Traffic KEYE-TV Austin - HOME
 

Zero Energy Home: So Hot It’s Cool

 Posted by on May 26, 2007
May 262007
 

By Barbara Kessler

It is 86 degrees as the afternoon sun assaults the asphalt roofs of Frisco, Texas. But it is cool inside the Craftsman-style house on Beacon Hill Drive.

The usual whir of the AC, ever present in so many area houses, has been replaced by the sounds of gently rustling leaves and breezes outside the screened porch. The windows are open. The hush is soothing. The cool is … puzzling.

zeroenhous.jpg How is it that this 3,800 square foot suburban house with its tall ceilings, state-of-the-art appliances and big airy windows has achieved this victory over the brutal Dallas summer and its henchmen, the electric companies?

Well, for starters, it was designed that way. The interior climate and its attendant energy cost was the priority one from the day one. This particular moderately air-conditioned, specially insulated “green” house was built to defy the conventional wisdom that it must be energy costly to live in the South.

It makes that statement — that green is attainable — serenely but decisively.

Whether you are looking to build a green home, green your own home or just want to keep up with this concept, a walk through this “Zero Energy” house is worth your time. (Or see another of this builder’s homes, once this one is sold.)

Tucked anonymously amongst other suburban homes, this house churns away at its energy conserving mission, its electric meter sometimes silent, sometimes moving forward and sometimes running backwards, says builder Jim Sargent of Anderson Sargent Custom Homes in the Dallas suburb of Waxahachie.

zerohouskitchen.jpgYes, you heard that right, backward. And in that instance, the power company has to send money back to 5357 Beacon Hill Drive for generating more energy than it consumes.

A happy thought.

And here’s another: The Frank Lloyd Wright-style house is positively elegant, trendy but distinct, and stocked from its sienna stained concrete floors to its specially insulated attic with all the latest design flourishes and modern household gadget wizardry.

That part was relatively easy, according to Sargent, a veteran green builder who worked in relative obscurity for a couple decades before finding himself at various podiums addressing homeowners and builders eager for an education in green building.

Building a house that keeps cool and is also pretty is not difficult, he tells them, despite the fact that 99 percent of all other new homes in United States Sunbelt manage to do a pretty good job of being pretty, and a pretty terrible job of being cool.

“We’re buying more energy efficient cars,” says Sargent, who was named 2006 Green Builder of the Year by the U.S. Energy Department, “but we are still buying Hummers to live in.”

Growing Greener
By the time Sargent built the Beacon Hill house in 2004 as a demonstration project, he had been building green houses on and off for about 30 years. He had experimented with green pilot projects in the 1970s, but gave up due to consumer apathy. But he again converted to building green in the mid-1980s.

It was a time when conservation seemed antithetical to the acquisitive aspirations of Americans. But it was then that Sargent was sending his sons off to college and realized that builders were doing a disservice to future generations with their wasteful ways.

He had begun to see his work as in conflict with building a better world for his grandchildren.

“I went back to my company and I said, ‘Guys, we know how to build a better home, and I’m ashamed of what we’re doing and we’re not going to do it.’ ”

And so with the zeal of the twice-converted, he launched a 15-year effort to go green. He studied the homes he built by monitoring their energy usage. He sought out the leading edge of technology in many areas of home construction and poured everything he learned into his work.

“I learned that I could build a home with conventional materials that would be a very high performing home. I could basically tell someone in a 2,500 square foot home that their heating and cooling bills would be about $1 a day. In a 1,200 square foot home I could get it down to about 35 cents.

The prospective homeowners often didn’t believe him. But later, when it turned out to be true, they believed.

Rule One: Don’t Make Ice Cream in the Attic
What Sargent discovered during this period, from the mid 1980s throughout the 1990s, wasn’t some complex or magical formula. What he learned was that re-shifting priorities, watching where the sun was and avoiding a few dumb mistakes could turn a potential energy disaster into an energy efficient house.

And the chief dumb mistake he discovered? It was sitting right there in the attic like the proverbial elephant in the room, huffing away in a part of the house liable to hit 130 to 150 degrees during Texas summer days, making cool air.

This was, and is, so illogical, that Sargent loves to dwell for a moment on the point with his audiences, telling them about the colleague who likened this folly to going into the attic to make ice cream.

Everyone nods. Yes, the attic is the last place you would go to make ice cream. Yet it had become the default spot for the indoor Air Conditioning equipment, particularly in Texas, where most houses lack basements and few builders or homeowners wanted to sacrifice air conditioned living area to the AC unit.

So instead, they put the AC in one of the two to three ovens we build onto our homes.

“We have about three ovens in our homes,” he says. “One is the attic. We have this dark roof up there and it will be 130 to 140 degrees. Another is our garages, we put (them) on the west side of the house and adjacent to and touching the house all day long — and any window that is getting direct sun is an oven.”

In the interest of energy savings, Sargent did sacrifice living area to the AC, putting the unit in a closet somewhere on a lower level in most of his houses he built. The trade-off paid off when homeowners saw the energy savings result.

Later, Sargent also started insulating some attics with foam insulation sprayed on the underside of the roof to keep the attic no more than 10 degrees hotter than the house itself.

Relocating or keeping the AC cool had a cascading effect. The units didn’t have to work as hard and he was able to use smaller units than conventionally proscribed for the square footage he was cooling.

Next he tackled leaks. He’d learned over the years that homes leak in amazing ways in a number of places you wouldn’t suspect and that sealing them up was more than a matter of putting in better windows (which doesn’t hurt) or caulking doorways (which also doesn’t hurt).

Here Sargent’s bag of tricks got a little more complicated. He began using a “blower door” — a sheet of fabric that seals up a doorway to the house and can be used to either pressurize or depressurize the building to better detect the leaks. He learned that leaks can cause a house to become a negative pressure air-sucking machine, and when that happens, the house literally breathes in hot air from outside or the attic during the summer. Not cool.

Rule Two: Don’t Let Your House Suck
Sargent could give a seminar on house leaks alone. His first pointer: They’re not necessarily where you think they are. His experimenting found leaks above showers and along interior walls. Many subcontractors — plumbers, electricians, drywall installers — are responsible for producing leaky homes, he said. Finding the leaks is an involved process, but like sticking the AC unit in an “oven” this was another case of an obvious oversight of a commonsense principle. A tight house holds the cool air. A leaky house has to refresh all the time.

The result, says Sargent, is that homebuilders or homeowners will try to fix the problem by installing a needlessly large AC unit to cool down the house that doesn’t seem to keep cool.

The large unit is powerful and can cool the house quickly, but then the cool ebbs away and the large, powerful AC unit has to crank on again. Repeat process several times throughout the day and you’ve successfully produced an “energy guzzler” home.

Tracking down leaks, by the way, is the first step for homeowners wanting to green up their existing abode. Sargent recommends hiring energy inspectors to find a home’s source of energy loss, such as leaks in walls and leaks in ductwork, particularly in the attic.

For more information on home energy raters (HERS) and other ways to have your home energy usage audited, see the Energy Star website.

Caulk and mastic (to seal ductwork) is an excellent first line of defense for a homeowner who isn’t ready for bigger improvements like insulating the attic, replacing windows or adding solar panels, Sargent said.

Speaking of Solar Panels…
Sargent’s demonstration house, which is listed for sale at $750,000, was built to be tight through rigorous quality control. The ductwork, for instance, was sealed with mastic, a putty-like substance instead of the duct tape that might later dry, crack and peel away. The house also sports casement windows, concrete floors heated by warm water coils underneath and exterior walls constructed of 10-inch thick concrete blocks (environmentally friendly concrete made partly from coal plant ash refuse was used).

The blocks have insulation inserts that shield the house from temperature changes outside but “communicate” with the inside, Sargent said. Their mass helps the house to hold warmth in the winter and slows the heating up that occurs in summer. In other words, the thick walls moderate the interior climate at both weather extremes.

The casement windows do more than provide a better seal than the typical metal frame windows used in zerhousebreeze.jpg the area. zerhouseporch.jpg They were installed to open vertically and catch breezes to help ventilate and cool (see the breezeway to the left and the screened porch below).

The house, which was featured in the Dallas parade of homes, has just about every green and eco-friendly device and building material that Sargent could throw into the package.

It is verfiably, certifiably green in a dozen ways, using sustainable materials like bamboo flooring, energy-conserving compact fluorescent light bulbs, low-water toilets, solar tubes that bring daylight to interior rooms and a special environmentally friendly drywall plaster.

Behind the scenes, the house takes every opportunity to power and provide for itself, using $75,000 worth of solar panels on the west roof to supply part of the home’s energy needs, the smallest possible one-ton AC system and a special dehumidification system that averts excessive operation of the AC for dehumidification.

The throw-in everything approach drove up the cost of the house, probably to the detriment of selling it because the price exceeds others in the neighborhood. But it’s message of conservation was thoroughly explored and demonstrated.

And energy conservation, as opposed to producing power, was the overarching principle. Without it, the house wouldn’t perform like it does.

Rule Three: Conserve, Conserve, Conserve
Sargent, his partner Vickie Anderson and the home’s designers, Barley & Pfeiffer Architects, searched for every way to conserve by design. They used passive solar concepts long cultivated by green builders, such as using “mass” (remember the concrete walls?) to capture warmth in the winter and ventilation to cool in the summer.

But some traditional rules of green building could not be employed. They were not able, for example, to orient the front of the house to the South, a standard plan in building green in the Northern hemisphere because it allows the inhabitants to bask in warm winter sun which is relatively low in the sky. Yet the summer sun, which casts a higher arc across the sky can be shut out.

The Beacon Hill lot faced east, not south, but this was just the sort of challenge that Sargent welcomed. He wanted to show that being green doesn’t depend on ideal conditions and send a message that you can adapt a low-energy house to its neighborhood. He’d been doing that for years. So the home’s east-facing windows were left large to let homeowner-pleasing light into the dining room and master bedroom, but were fitted with awnings to block the noon day sun.

The designers then turned their attention to the south side, where a porch and breezeway was added to take advantage of Texas’ southerly winds. Casement windows were positioned to catch the breezes and an overhang was drawn in to shade the porch.

The west side of the house got the solar panel on the roof to capture the power of the sun, and smaller windows in the home’s office to mitigate the heat of the sun.

“In the afternoon, I never want the sun to hit a west window,” Sargent says. “The house has been challenged all day long and the amount of heat that goes through the glass is staggering.”

Behind the house, large water tanks store recaptured water that can be used to water the lawn. But the lawn itself was minimized with stone pathways and xeriscaping, using low-water plantings adapted or native to the area.

Like an ecosystem, the house’s systems interlink and support each other. Water is heated via the solar panel, but only as much is heated as bathroom users “call for” with special doorbells. Water condensation from the AC is funneled to the water recapture system, including water from the dehumidification process that relieves the burden on the AC. A new product among foam insulation offerings, Icynene, also takes the heat off the AC, and was sprayed on the underside of the roof so the cool unit could be placed in the attic.

In the winter, the heat from the family room fireplace is captured and re-circulated.
And so it goes, on and on. A sort-of living organism or circle of life in miniature.

The net result: Zero. Energy that is.

(If you a home buyer interested in this house contact the Abio AHK Realty office, 4801 W. Lovers Lane, 214-358-5550.)

Copyright © 2007 | Distributed by Noofangle Media