A recent study conducted by the National Institute of Standards and Technology (NIST) determined that air barriers are a cost effective measure to be installed in buildings. Most notably, the study showed that the energy savings ranged from 30 – 40 percent for heating climates, and 10 - 15 percent for cooling climates.
“We are excited about the study’s findings, as it confirms what we have believed all along—that installing an air barrier, such as Sto Guard, is an important, cost effective step in the building process,” said Lisa Petsko, product manager. Sto Guard from Sto Corp. is a spray-on waterproofing/air barrier that can be used behind various claddings in commercial and residential markets.

The report, entitled “Investigation of the Impact of Commercial Building Envelope Airtightness on HVAC Energy Use,” was completed by Steven J. Emmerich of Building and Fire Research Laboratory; Timothy P. McDowell of TESS, Inc.; and Wagdy Anis of Shepley Bulfinch Richardson and Abbott, and shows a simulation study of the energy impact of improving envelope air tightness in U.S. commercial buildings. Despite common assumptions, measurements have shown that typical U.S. commercial buildings are not particularly airtight. Past simulation studies have shown that commercial building envelope leakage can result in significant heating and cooling loads.

To evaluate the potential energy savings of an effective air barrier requirement, annual energy simulations were prepared for three nonresidential buildings (a two-story office building, a one-story retail building, and a four-story apartment building) in five U.S. cities. A coupled multi-zone airflow and building energy simulation tool was used to predict the energy use for the buildings at a target tightness level relative to a baseline level based on measurements in existing buildings. Based on assumed blended national average heating and cooling energy prices, predicted potential annual heating and cooling energy cost savings ranged from 3 to 36 percent, with the smallest savings occurring in Phoenix and Miami.

“This study shows tremendous support for using an air barrier to construct an airtight building envelope,” said Petsko. Problems that can occur because of air leakage and condensation are minimized with an air barrier because the barrier provides an effective and economical means of controlling moisture in wall assembles. By using a barrier to construct an airtight building envelope, the risk of moisture problems—decay, corrosion, loss of insulation value, mold growth, and indoor air quality (IAQ)—may be minimized.

For the complete survey results, visit http://fire.nist.gov/bfrlpubs/build05/PDF/b05007.pdf and download the document.

Based in Atlanta, Sto Corp. produces a range of cladding and coating systems for building construction, maintenance and restoration, is ISO 9001-certified and operates production plants strategically located to serve more than 200 distributor shipping locations across North America. For more information, visit www.stocorp.com.