Heating, Cooling and HVAC

The Basics
There is still a lot of confusion about exactly what green building is. For most experts, there are five main characteristics that define it:

1. Having an environmentally friendly site selection or “footprint.” Some of the factors involved are orientation of the house to maximize natural sunlight for heat and light, as well as shade for cooling. As a result, the home’s furnace and air conditioning don’t have to work as hard to maintain a comfortable house. Another goal is making a minimal impact on the area in which the house is built. Forget clear-cutting the entire lot; take down only the trees and bushes that would interfere with construction. The remaining trees can help cool the house in the summer and act as a windbreak in the winter. And locating the home near shopping and other services will keep the amount of driving down—a win for the entire enviroment.

.
2. Using energy efficient designs and materials while building a “tighter” home to prevent HVAC loss. The use of sunlight and shade for heating and cooling is as old as mankind, but there are designs and materials specifically designed to keep the house nearly air-tight. With less outside air infiltrating the home, the indoor climate is much easier to control. LED lights use a fraction of regular incandescent bulbs, while Energy Star appliances are certified to meet strict guidelines about how much electricity they require to operate.

Because higher insulation standards and Energy-Star-compliant appliances have evolved over the last few decades, energy efficiency is often the first place builders start when going green. “Energy efficiency is certainly some of the low hanging fruit,” says Brian Gitt, executive director of Build It Green, a non-profit, third-party green building education and certification group in Berkeley, Calif.

.
3.Reducing a home’s water consumption through low-flow fixtures. It’s true that the earliest low-flow plumbing fixtures caused problems for some homeowners, but today’s versions are as good—if not better—than the old water hogs. One technology is the incorporation of air into the process; the result is a low-flow shower that feels just as strong as the one using much more water.

.
4. Promoting a healthy indoor air environment. Yes, air-tight houses are critical to energy efficiency, but an unwelcome result is indoor air quality that is five times more polluted than the air outdoors! Green builders often use some kind of fresh-air ventilation to exhaust the stale indoor air to the outside, while bringing in fresh air into the house and conserving energy at the same time.

.
5.Emphasizing material conservation and waste reduction while using sustainable products in design and construction. Engineers in the building-materials business have designed all kinds of products to save lumber by using optimal value engineered joists and beams that require minimal trimming and boring for mechanical run. Green builders can go as far as recycling job-site waste and using it for mulch in the newly planted yard.

Another form of waste reduction is building houses that will endure for years before requiring any serious maintenance. Metal or cement tile roofing, for example, will hold up much longer than standard shingles; many have life expectancies of half a century.

No national standards
To help builders get a better handle on green building, the National Associatio of Home Builders has created its Model Green Home Building Guidelines. “It’s a resource guide for builders who want to figure out what green building is and learn about green building techniques,” English says. The Guidelines can be downloaded from the website; it’s also available in hard copy and on a CD-ROM through the NAHB.

While NAHB’s Guidelines provides a starting point, there’s still no nationally recognized standard for green homes. Instead, there are about 70 regional groups across the country promoting green building in their own regions. They include Build It Green in Berkeley, Calif., and the Southface Energy Institute in Atlanta, Ga., which works with the Greater Atlanta Home Builders Association to educate builders. “We don’t design and build green homes, but we train and provide technical assistance to those who do,” says Dennis Creech, executive director at Southface, whose EarthCraft House program serves as a green benchmark for builders in the Southeast.

A national standard may be on its way, though. The U.S. Green Building Council, a non-profit group based in Washington, D.C., is currently testing its LEED for Homes pilot program in 12 different regions across the country. Jay Hall, acting manager of the program, hopes to “piggyback” with existing local groups such as Southface and have a national standard in place by late 2007. “We’re trying to create a national standard for green homes, and send a clear message about what constitutes green as you go from one region of the country to the other,” Hall says.

Green building now
Plenty of builders are using green techniques today—and they’re taking it very seriously. For example, Christopherson Homes, which puts up approximately 300 homes per year in northern California, has earned Build It Green’s “GreenPoint Rated” certification. Amy Christopherson Bolten, director of community relations, says Christopherson’s homes employ a variety of green techniques:

* Dual-flush toilets
* Low-VOC paints
* Formaldehyde-free insulation
* Forest Stewardship Council-certified lumber, which comes from forests managed with sustainable methods
* 2×6 wall studs, which allow the studs to be spaced farther apart to save lumber wood, and make the walls thicker to allow for more insulation.
* Ventilation systems wrapped and sealed to prevent heat and air conditioning from leaking out.

“Now, we can show our customers how much they’ll save in energy costs based on our specifications,” Christoperhson Bolten says.

Hurdles still present
Being green isn’t always easy, though. For example, FSC-certified lumber can be problematic. “It’s hard to get, and it’s expensive, about 20 to 30 percent more than regular lumber,” says Christopherson Bolton, who estimates that building green adds a few thousand dollars in costs to each house.

Training subs to build to green specs can be a challenge, too. Then there’s the fact that many homebuyers still don’t know what green building is. “The public still seems to be on a learning curve with it,” Christopherson Bolten says.

That learning curve appears to be on the upswing, though. With consumers hyper-sensitive to energy costs while becoming more environmentally conscious in general, most observers agree that green is the color of the future for builders and buyers, alike. “The builders in our program aren’t just a couple of custom-home guys in a fringe market. They’re mainstream builders,” says Southface’s Creech. “Eventually,it is a fact that the home-buying public is going to demand that their homes be built this way.”
Click to learn more about Green Building

Source:Hgtvpro.com