Researchers with the US Department of Energy Pacific Northwest National Laboratory have found that commercial buildings could cut their heating and cooling electricity use by an average of 57 percent with advanced energy-efficiency controls. Actual energy savings ranged from 20 to 90 percent. The results come out of a year-long trial of the controls at malls, grocery stores and other buildings across the country.

The findings include:

• heating and cooling are among the biggest energy consumers in buildings, largely because most buildings don’t use sophisticated controls.
• packaged HVAC units in commercial buildings in the US consume the same amount of electricity each year as 8 million US residents, or about 2,600 trillion British thermal units of energy.
• HVAC units can be configured with advanced controls to automatically adjust their operations based on conditions inside and outside a building.
• using sensors and variable-speed motors, the controls decide when and how fast ventilation fans should run, and if the units can use naturally cold air from the outside instead of mechanically cooling indoor air.
• larger buildings such as malls, which need bigger HVAC units, saved more energy than smaller buildings. And buildings that ran ventilation fans more, such as stores open long hours, tended to save more energy.
• on average, it will take a building owner three years to recoup the cost of buying and installing advanced controls.

The researchers say that building owners interested in upgrading or replacing their HVAC systems can learn more from the Advanced Rooftop Campaign, which was formed by DOE’s Better Building Alliance, the American Society of Heating, Refrigerating and Air Conditioning Engineers, and the Retail Industry Leaders Association.

More information from PNL at http://www.pnnl.gov/news/release.aspx?id=1055