Pacific Northwest National Laboratory issued a report recently on their study examining the performance of highly insulating windows. The study was conducted in all-electric, factory built “lab homes” and examined the energy, air leakage and thermal comfort of the windows.

The study, conducted from February 3 to April 13, 2012 for the heating season and July 6 through August 18, 2012 for the cooling season, centered around results gleaned from Lab Home A, a “baseline” home retrofitted with standard double-pane clear windows and patio doors and Lab Home B, retrofitted with triple-pane vinyl-frame slider window and patio doors. Lab Home B had a U-factor of 0.2 and a solar heat gain coefficient of 0.19.

Over the course of the study, researchers found that Lab Home B saved 12.2 percent, or 1,784 kilowatt-hours per year over Lab Home A in annual energy savings.

According to the research, an EnergyPlus model was used in the homes to compare cost savings. Lab Home B offered a whole-building energy savings of 13.9 percent during the experiment through both the heating and cooling seasons. In the study, “The overall whole-house energy savings of Lab Hom B compared to Lab Home A are 11.6 percent ± 1.53 percent for the heating season and 18.4 percent ± 2.06 percent for the cooling season for identical occupancy conditions with no window coverings deployed.”

Click here to view the full report.