If all U.S. commercial buildings fully used controls for daily operation, they could reduce energy consumption by the amount of energy that is currently used by 12-15 million Americans each year, according to a report authored by researchers at the Department of Energy’s Pacific Northwest National Laboratory (PNNL). These savings would cut energy use in commercial buildings by 29%.
“Most large commercial buildings are already equipped with building automation systems that deploy controls to manage building energy use,” says report co-author and PNNL engineer Srinivas Katipamula. “But those controls often aren’t properly programmed and are allowed to deteriorate over time, creating unnecessarily large power bills. Our research found significant nationwide energy savings are possible if all U.S. commercial building owners periodically looked for and corrected operational problems such as air conditioning systems running too long.”
Commercial buildings account for about 20% of total energy use nationwide, and only 15% have building automation systems with controls that help reduce energy. Examples include sensors for lights and heating and cooling controls that change throughout the day.
The report addresses 34 total energy efficiency measures to improve commercial building performance. Additionally, the researchers looked at how packaging some of these together impacts performance.
The efficiency measures that showed the greatest potential for energy saving include:
- Lowering temperature setpoints for heating in both the daytime and nighttime and increasing them for cooling for about an 8% reduction
- Reducing the minimum rate for air to flow through variable-air volume boxes to reduce energy use by about 7%
- Limiting heating and cooling to when the building is occupied for a roughly 6% reduction
Across all climates, undertaking these changes could have an average energy savings of 29%, but some building types have even greater potential for energy reduction. For example, secondary schools save about 49% on average.
Unsurprisingly, buildings that are already inefficient would see the greatest impact. Inefficient buildings have a potential national energy saving range of 30-59%, typical buildings could save from 26-56% and efficient buildings could cut back anywhere from 4-19% percent.
Read the report “Impacts of Commercial Building Control on Energy Savings and Peak Load Reduction” at www.pnnl.gov.