Portland State’s Green Building Research Laboratory studied how to save on heating bills by monitoring four Portland area homes that installed Indow window inserts. The study initially predicted that Indow window inserts would save homeowners 10 percent on their heating bills. But the study found it actually saved them almost 20 percent. The scientists believe the extra savings came because the homeowners felt so comfortable that they turned their thermostats down.
Indow window inserts increase comfort in two key ways. First, they almost completely block the drafts coming through a window. The window inserts are composed of a sheet of acrylic glazing edged with the company’s patented Compression Tube. The inserts install very easily without a mounting bracket but seal out the cold air and create an insulating air pocket in between the window insert and the window.
Also a person feels warmer standing next to acrylic than a single-pane of glass even if the room temperature is the same in both cases. And that in turn makes that person less likely to turn up the thermostat.
Indow inserts are installed by being pressed inside the interior of existing window frames. Homeowners can remove them and then reinstall them in just seconds.
It was an Oregon BEST grant that paid for a study early on proving the energy efficiency of Indow inserts.
Those results were backed up by a U.S. Department of Energy study released earlier this year that found Indow inserts led to a more than 20 percent reduction in heating, ventilating and air-conditioning use in a Seattle home.