NREL
 

New Design Tool Can Help Cut Building Energy Use By Up to 50 Percent

Energy Efficient Buildings Can Substantially Reduce Global Warming

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Golden, CO, January 22, 1998 — Designing state-of-the-art, energy efficient buildings just got easier.

A new, upgraded software package can help almost any architect or engineer evaluate passive solar and efficiency design strategies in a matter of minutes on an office personal computer. The new software - Energy-10 version 1.2 - is an upgrade to the original program developed at the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL).

The new Energy-10 contains more than 30 upgrades that help architects use the software for designing energy efficient residential buildings. The earlier version focused mostly on small commercial buildings.

Saving energy is the point of Energy-10. "This puts in the hands of a designer a tool that enables them to walk through the design process and understand the consequences of design decisions on energy use as they go," said Energy-10 author Doug Balcomb, senior engineer at NREL. "Typically, we can cut energy use by 50 percent without necessarily adding anything to the cost of a building."

Almost 40 percent of all energy consumed in the United States is used in buildings. Two-thirds of all electricity produced in the U.S. is used to light, heat and cool buildings. This energy use accounts for an estimated 35 percent of the nation's total greenhouse gas emissions.

Helping architects and engineers understand the energy implications of their work is critical in any strategy to reduce greenhouse gas emissions and global warming.

Energy-10 allows an architect to watch a detailed simulation of how his building will use energy and shows ways to reduce overall energy consumption. The software simulates a year of hour-by-hour operations a process that requires about one billion calculations in less than a minute and displays annual, monthly or hour-by-hour energy performance graphs.

The software incorporates detailed historical weather data for 78 locations around the country, enabling architects to accurately match their buildings with a sites weather patterns.

A key enhancement in version 1.2 is AutoSize, a feature that tells designers how large of a heating, ventilation and air conditioning (HVAC) system a building will need. The more energy-saving features a building uses, the smaller the HVAC system thats needed.

"The HVAC system is 15-20 percent of a buildings cost," Balcomb said. If you can downsize that by 30-40 percent, you can cut up to 10 percent of a building's overall cost. The savings can cover the other energy-saving features, so you can design an energy efficient building that doesn't cost any more to construct.

Another key feature allows designers to evaluate the effects of daylighting in a comprehensive way. The use of daylighting is a critical design decision for many offices and schools, which are used primarily during the day. Using fewer artificial lights reduces electricity consumption and the need for cooling. Studies have shown that daylighting in schools can lead to an improvement in student test scores of 5-21 percent.

Energy-10 version 1.2 is the result of collaboration between NREL, Lawrence Berkeley Laboratory and the Berkeley Solar Group. It is being marketed and sold by the Passive Solar Industries Council (PSIC) in Washington, D.C., which also provides training workshops and user support. PSIC can be reached at 202-628-7400, ext. 210.

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