Air leakage in residential and commercial buildings is a major source of energy waste. According to the U.S. Energy Information Administration, buildings consumed about 40% of the total energy used in the U.S. in 2016.1 Making building envelopes tighter through the proper use of continuous air barriers can help significantly reduce this energy usage—but by how much?
That’s not a simple question to answer. Variables like local climatic conditions, building size and design, and energy source all play a role in determining the impact reducing air leakage can have on energy use. That leads to some pretty complex calculations.
Fortunately, the scientists at Oak Ridge National Laboratory have introduced a tool that can help: their Web-based Energy Savings Calculator. By selecting your geographic location, building type, floor area, and current and target air leakage rate, the calculator automatically inputs costs for electricity and fuel based on averages for that location. The tool provides a graphical estimate of predicted savings by reducing air infiltration at the target leakage rate.
Comparing different air leakage target rates and their effect on energy costs is very eye-opening.
For example, according to the calculator, a 25,000-square-foot standalone retail building in Boston, Massachusetts could save nearly $4,800 dollars annually in electricity and natural gas costs by moving from a leakage rate of 5.4 to 2.0 liters/square meter. Move down to a leakage rate of 1.25 and that predicted savings rises to $5,400. Reduce leakage to the low level of 0.25 and potential savings could be $6,000 a year.
Interestingly, the same building in San Francisco could save about $760 in energy costs at a leakage rate of 2.0 liters/square meter. Clearly, the local climatic conditions play a large role in energy savings, with colder climates reaping the greatest potential savings, mostly in fuel costs.
These examples, based on sophisticated data modeling, are dramatic evidence of the difference a continuous air barrier can make in reducing energy usage and costs. And that’s a difference that keeps giving, year after year.
Energy savings is just one important benefit of continuous air barriers.
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