Who makes it: Indow Windows
When Sam Pardue learned it would cost $35,000 to replace the distinctive-but-leaky windows on his 100-year-old Portland home, he knew there was an opportunity for a new solution.
“There were cheaper windows available but it seemed like a horrible thing to do to rip out those original windows and replace them with cheap vinyl ones,” he said.
Instead, he designed Indow Windows, thermal inserts that adhere to the inside of window frames through a pressurized spring. He was inspired by the thermal lining of refrigerator doors.
Adding Indow Windows to single-pane windows can achieve 94 percent of the energy savings of double-pane replacements at a fraction of the cost, according to the company. The inserts plus installation run about $13 per square foot, so refitting a house with 14 average-sized windows costs about $2,400.
Installers first come to a site to take measurements – they can fit the inserts even to out-of-square windows – then return with custom-cut inserts that can be installed within a few hours.
The spring mold lining, made of PVC-free silicon tubing, forms an airtight compression around the frame.
“That’s what gives the Indow Window the force to stay in place without any nails, screws or adhesives,” said Pardue, the company’s founder and chief executive. “The low-profile design almost disappears when you install it.”
“For preserving the architectural character of the structure, that’s a huge deal,” he added. “We have a lot of enthusiasm from architectural preservationists because it’s such a light touch.”
What’s more, the U.S. Department of Energy estimates that 43 percent of U.S. homes still have single-pane windows, so the energy savings potential is significant.
“The problem is that double-pane replacement is so expensive,” Pardue said. “Hundreds of people have gotten quotes for double-pane windows and had a heart attack just like me.”
Indow Windows launched in Portland in 2010 and plans to expand throughout Northwest.
